From Water to Land: 10 Amazing Types Of Amphibians

There are nearly 8,000 types of amphibians, including some of the most unusual and exciting creatures found on land and water.

About two million species of animals inhabit Planet Earth. More than that, scientists discover and categorize about 10,000 other new species every year. Animals are broken down into classes which include vertebrates and invertebrates, or animals with or without spines.

Amphibians belong to the vertebrate class along with birds, fish, mammals, and reptiles. All amphibians are cold-blooded, meaning they cannot generate body heat on their own. For that reason, they must rely on their environment to keep them cold or warm enough for survival.

Going further, most amphibians undergo a metamorphosis from a juvenile to an adult form. For example, frogs begin as tadpoles with gills and a tail. As they mature, they develop lungs. Over time, four legs replace most types of amphibians tails.

The Types of Amphibians

Amphibian species include three subgroups or orders. Firstly, there is the Order Anura which includes about 6,500 species of frogs and toads.

Secondly, the Order Caudata or Urodela includes about 680 species of newts and salamanders. Thirdly, Order Apoda or Gymnophiona, includes about 200 species of caecilians.

Frogs and Toads

Types of amphibians: European Common Frog (Rana temporaria) & European Toad (Bufo bufo) on a grassy patch of soil
European Common Frog (Rana temporaria) & European Toad (Bufo bufo): Image CC by 2.0 Generic, by Thomas Brown, via Wikipedia Commons

Frogs and toads typically have short bodies, webbed fingers and toes, and no tails. And, they usually have bulging eyes.

Newts and salamanders

yellow-spotted salamander, an amphibian, on a white background
Spotted salamander (Ambystoma maculatum): Image CC by 2.0, by Brian Gratwicke, via Wikipedia Commons

Newts and salamanders look similar to lizards and have short legs, skinny bodies, and long tails. Surprisingly, salamanders and newts have the remarkable ability to re-grow lost limbs and tails.

Caecilians

Caecilian: one of the types of amphibian with eggs in wet soil
Presumed Microcaecilia dermatophaga mother with eggs: Image CC by A 2.5 Generic, by Wilkinson M, Sherratt E, Starace F, Gower DJ (2013), via Wikipedia Commons

Caecilians don’t have any legs and resemble worms or snakes. That is because they mostly live underground, or in the substrate under streams. As a result, they have strong skulls and pointed noses to help them burrow through mud and dirt.

Fun Facts About Types of Amphibians

Amphibians are an evolutionary link between water-dwelling animals such as fish and land-dwelling animals such as mammals. Let’s be honest, they are some of the most fascinating animals on Planet Earth.

For example, amphibians have extremely primitive lungs. However, they have thin, moist skin that absorbs limited amounts of oxygen. So, you could say some types of amphibians breathe through their skin.

Another exciting fact about them, amphibians are carnivores and predators. But, they cannot chew their food. So, they swallow their prey whole.

Amphibians are also one of the planet’s most endangered animal species. It is believed that nearly half of the world’s amphibians are threatened species. That’s due to a combination of factors, including habitat loss, pollution, and climate change.

10 Amazing Types of Amphibians

Amphibians include some of the most amazing and unusual vertebrates found on earth. Much like their ancestors, most of them stick close to water.

We gathered a collection of photos of 10 of the most exciting types of amphibians currently roaming the earth, below. Then, we included a brief introduction to each one.

1. Axolotl

The axolotl is a type of salamander that is native to central Mexico. Unlike many other types of amphibians, axolotl larvae do not undergo metamorphosis when they reach maturity. As a result, they retain their gills, and tails, and are entirely aquatic throughout their life cycle.

photograph of an axolotl under wooden structure in a tank - one of the types of amphibian
Types of amphibians: Axolotl. Image via Instagram.

2. Fire Salamander

Fire salamanders are native to the forests of central and southern Europe. These types of amphibians stay near to ponds and streams, which they rely on for breeding. Another cool fact, they are active both night and day.

photograph of a fire salamander - a type of amphibian
Fire Salamander. Image via Instagram.

3. Golden Toad

The golden toad was native to the tropical mountain regions of Costa Rica, known as montane cloud forests. Sadly, golden toads are one of many types of amphibians thought to be extinct since they have not been seen since 1989.

photograph of a golden toad - a type of amphibian
Golden Toad. Image via Instagram.

4. Green Tree Frog

Green tree frogs are native to New Guinea and Australia. Their colors range from brown to green, depending on the surrounding air temperature. These are one of the most abundant types of amphibians dwelling in trees.

photograph of a green tree frog - a type of amphibian
Green Tree Frog. Image via Instagram.

5. Hellbender

Hellbenders are native to wetlands of Kentucky, Pennsylvania, and Tennessee. However, they are sometimes located in smaller numbers in the surrounding states. Sadly, hellbenders join other types of amphibians on the IUCN Red List of Threatened Species.

photograph of a hellbender - a type of amphibian
Hellbender. Image via Instagram.

6. Luristan Newt

These black and white spotted newts are native to the Luristan Province of Iran. While they look like cows, they are clearly amphibians. The Luristan newt is listed as “critically endangered” on the IUCN Red List of Threatened Species. However, they are currently protected under Iranian law.

photograph of a black and white spotted luristan newt - a type of amphibian
Luristan Newt. Image via Instagram.

7. Poison Dart Frog

The poison dart frog is native to the subtropical and tropical regions of South America. They can also be found in Central America. Bright colored dart frogs are extremely poisonous. However, dart frogs with cryptic or dull coloring have nominal toxicity. In fact, some are not toxic at all.

photograph of a poison dart frog - a type of amphibian
Poison Dart Frog. Image via Instagram.

8. Red-Eyed Tree Frog

The red-eyed tree frog is native to the Neotropical rainforests of Mexico and Central America. In addition to their bulging red eyes, these tree frogs have webbed orange feet and blue and yellow flanks. Luckily, due to their large number, they are listed as “least concerned” by the IUCN Red List of Threatened Species.

photograph of a red-eyed tree frog - a type of amphibian
Red-Eyed Tree Frog. Image via Instagram.

9. Endemic Tailed Caecilian

The endemic tailed caecilian is native to the tropical regions of Sri Lanka. Resembling a giant earthworm, endemic tailed caecilians range in size from 9 inches to nearly 16 inches. Additionally, the endemic tailed caecilian is listed as vulnerable by the IUCN Red List of Threatened Species.

photograph of a sri lankan endemic tailed caecilian - a type of amphibian
Sri Lankan Endemic Tailed Caecilian. Image via Instagram.

10. Tiger Salamander

The tiger salamander is native to the mountainous and lowland regions of the United States and Mexico. Unlike other types of amphibians, they tend to avoid water. Additionally, they can grow to lengths of 12 inches and larger.

photograph of a tiger salamander - a type of amphibian
Tiger Salamander. Image via Instagram.

What We Learned About the Types of Amphibians

We hope you enjoyed our article and accompanying photos of amazing and unique types of amphibians.

You have seen our favorite types of amphibians. Now we want to know about your faves. Using the comments section, let us know any unusual types of amphibians you would like to see included in future articles.

Featured image: A collage of various amphibians CC by ASA 3.0 Unported, by Various Artists: File:Litoria phyllochroa.JPG, File:Seymouria1.jpg, File:Notophthalmus viridescensPCCA20040816-3983A.jpg, File:Dermophis mexicanus.jpg, via Wikimedia Commons

How to Prepare a Microscope Slide to Zoom In on a Specimen

Microscopes offer a great way to discover an entire universe that lies beyond what we can see with the naked eye. From harmful bacteria to beautiful and unique crystal shapes, microscopes open an entire world for us to explore which would otherwise be impossible to learn about. To experience this vast but minuscule new world it is important to know how to prepare a microscope slide for the different materials you'll want to examine close up.

This article serves as a simple, easy-to-follow guide on how to prepare a microscope slide. This includes a list of the materials needed to mount slides, an explanation of the different techniques of mounting slides and when to use them, what techniques to use for the best results depending upon the specimen, and which style of slides to choose for which type of observations you'll be making. Follow this easy guide to explore what the microscopic world has to offer!

How to Prepare a Microscope Slide

microscope slide

Image via Pixabay


Gather the Materials Needed

When considering how to prepare a microscope slide, you should first gather all the necessary materials for creating slides. As you will see later on in this instructional guide, different types of materials you wish to observe under a microscope call for different types of slide mounts. Also, the different types of observations you wish to make each have their own requirements regarding shape of the slide you should use. Regardless of what you are observing and how you will observe it, there are certain basic materials you will need. These materials include:

  • Slides
  • Coverslips
  • Pipette (also called a dropper)
  • Tweezers
  • Cotton or paper towel
  • Petroleum jelly
  • Stains (chemical or organic)
  • Fluids for wet mounting
  • Samples of the material you wish to observe

Microscope slides can be made of glass or plastic, feature a flat or concave shape, and each one will have its own advantage and purpose, depending on what type of observations you will be doing. For example, plastic slides are more resilient and less likely to break, so they are safer to handle as they have no sharp edges, so they are a better choice if you'll be preparing your microscope slides outside.


Glass slides generally have a better reflective index and are less likely to scratch, which allows for better photos to be taken of the specimens than those on plastic slides. Choosing glass or plastic slides is a personal choice, but regardless of the materials the slides are made of, the standard size of a typical microscope slide is approximately 1X3 inches and between 1mm-1.2mm thick.

Wet vs. Dry Mounts


micropscope slide on a stage

Image via Pixabay

There are two main methods of mounting microscope slides: the wet mount method and the dry mount method. The dry mount technique is simpler and is ideal for larger specimens that that are inorganic or dead matter. Feathers, pollen, hair samples, and insects are all Ideal examples for dry mounts. Thicker or opaque samples might have to be sliced thinly to allow light to pass through the specimen which will help you see things better under the microscope. Because these samples are lifeless, these slides rarely expire and can be preserved for longer periods of time.


Wet mounts are more complex and require more attention, so keep this in mind when planning how to prepare a microscope slide. Generally used for observing organisms that live in water and other liquids, such oils, glycerin, and brine, wet mounts are also useful for when the material itself is a fluid, such as observing blood. Anything that doesn't require the addition of water to be observed under a microscope needs to be prepared on a wet mount.


It is also important to note that using a wet mount technique has its limitations concerning living organisms. Because wet mount slides will ultimately dehydrate the living organisms within the slide, those organisms have a limited lifespan while on the slide, and therefore there is a limited shelf life for the slide itself.


For example, certain organisms, such as protozoa, offer us a very limited window of observation, as they can only survive in a wet mount slide for approximately 30 minutes if the slide is allowed to dehydrate. A way to slow this process down and have more observation time in this situation would be to seal the edges of the slide with petroleum jelly. This way, the liquid will remain in the slide longer and the life of the slide will be extended for a few days.


Another issue concerning wet mount slides involves specimens that are too large to allow the coverslip to be placed comfortably on top and rest flatly on top. Here, you might place ground pieces of glass from a spare coverslip to encase the specimen to provide some extra space for the specimen to be secured. You may also place a small cotton strand around the edge to perform the same function and corral the specimen in place. This is also a great technique to use when live specimens are quick moving, as this will limit their movement and slow them down, giving you a better observation experience.

Smears, Squash, and Stains–How and When to Use Each


scientist focusing a microscope

Image via Pixabay

Knowing how to prepare a microscope slide properly also involves applying the proper technique, as different techniques are used depending on the material being observed. Depending upon which type of material you will be looking at under your microscope, you should use the right technique to get the best results. Using these three techniques under the right circumstances shows you are certain in how to prepare a microscope slide properly.

Smear Slides

Smear slides are fairly straightforward and create microscope slides that look exactly as the name suggests: a thin smear of material across the clear slide. This method is primarily used for blood samples or samples that are fluid in nature. This is done by using a pipette (or dropper) to place a drop of the material onto the slide. Using a second slide to smear the material across the first, you can create a very thin coating that allows for clear observation. This slide creation technique allows the specimen to dehydrate at a moderate pace.

Squash Slides

Squash slides are a way to prepare soft material for observation. Drop the fluid of choice onto the slide and press down slightly as to flatten the sample and squeeze the liquid from it without breaking the slide or coverslip. Use a tissue to absorb the excess liquid. This wet mounting technique is ideal for tissue or sponge samples.

Stain Solutions

Stain applications are a great way to distinguish between living and non-living cells in your specimen sample. This technique is primarily done in the biological science labs to help scientists identify diseases, especially different bacteria, and examine the minute characteristics of cells more closely.


Depending on what exactly you are trying to identify, there are several types of stains you can use, but the most common is iodine. Prepare the wet mount as you would with any other fluid, in this case using the staining solution, place the coverslip on the edge of the slide, and slowly pull the stained liquid sample across the slide. Use a paper towel to absorb the excess liquid.

Flat vs. Concave Slides—Which to Choose?


When first learning how to prepare a microscope slide, it is important to consider what type of material you will be observing. It is equally important to consider what type of observation will be best based on the consistency of the material of your sample. This is where you will decide whether you want to preserve your slide and keep it for further use, or if that is not possible, perhaps it is more practical to not use a coverslip for your wet mount. But how can you made observations under your microscope without a coverslip?


This is made possible through the use of a concave style slide. Also known as a depression slide or a well slide, this microscope slide is shaped so it can hold a drop of liquid in an indentation without the use of a cover. As expected, this option is considerably more expensive, but will allow you to observe a live organism and preserve it for future observation as flat wet mounts will shorten the life span of the specimen considerably. Concave slides also allow for free movement of specimens within the drop of water or fluid present.

Conclusion


microscope objectives

Image via Pixabay

Microscopes can lift the veil on a whole new world for you, your friends, and family, especially know that you know the various aspects about preparing microscope slides. Knowing how to prepare a microscope slide properly lets you to observe a variety of materials, witness what changes occur over time, compare specimens, and potentially preserve those specimens indefinitely! Learning how to prepare a microscope slide properly offers many benefits, and we hope this quick guide has given you the confidence you need to prepare slides of your own while you're out in the field or in your home laboratory.

10 Questions To Study For A Mitosis Quiz In AP Biology

If you need to prep for a mitosis quiz in AP Biology, you are going to need to understand the difference between mitosis and meiosis thoroughly.

Many students fail to be able to identify the difference between the two biological processes accurately. So, you don't want to get disappointing results on your mitosis quiz; there are a few key points you are going to want to study.

Remember to acquaint yourself with the following before you think you are prepared enough for a mitosis quiz.

  • There are six different stages of mitosis.
  • You want to be able to visualize and analyze diagrams displaying the stages of mitosis confidently.
  • It is good to be aware of any irregularities during mitosis and resulting genetic consequences

Give yourself ample time to take comprehensive notes when studying your AP Biology material. Don't try to memorize everything, but seek to understand and make connections between the information. It may also be helpful to draw out the processes of mitosis, labeling each stage with a description that you can understand easily.

Ask yourself questions about what step comes next, and predict if something were to go wrong in the process what would be the result?

Taking steps to interact with your material will help you make more sense of things. You don't want to only memorize and regurgitate the material without having a clear visual understanding of the what and why of the process.

What Is Mitosis?

Mitosis is the name given for the process of a cell's duplication. When there is one cell with a single set of chromosomes, it goes through a step-by-step process where you end up with two cells that have identical sets of chromosomes.

When there are breakdowns or problems with the mitosis process, genetic diseases or anomalies are created.

Check Out These 10 QuestionTo Study For A Mitosis Quiz

girl studying

Image by Adina Voicu from Pixabay​​​

Out of all the information covering mitosis and meiosis, you may want to consider the following questions to help prepare you for an upcoming mitosis quiz. Choose to break down the information as you see fit and in a language, you can understand. Again, drawing images to help you better conceptualize the process is helpful, as well as using correct terminology.

Which Structure Is Responsible For Moving Chromosomes During Mitosis?

The centromere is a region of DNA that holds together the two chromatids of a duplicated chromosome. Centromeres are responsible for attaching microtubules and direct the movement of chromosomes in both the process of mitosis and meiosis.

First, the chromosomes move toward the center of a cell during metaphase, and then they proceed to opposite directions during anaphase.

 Why Do Chromosomes Fail To Separate Within Mitosis?

Image by Colin Behrens from Pixabay 

Nondisjunction is when a pair of homologous chromosomes fail to separate. There are three forms of nondisjunction, and two happen during the process of meiosis I and meiosis II. 

When the sister chromatids fail to separate during the process of mitosis, the number of chromosomes is abnormal, resulting in aneuploidy.

If a single chromosome is lost from a diploid genome, it is called monosomy. If a chromosome is gained, it is called a trisomy.

When chromosomes fail to separate correctly, it can lead to a genetic disorder such as Downs Syndrome or Turner Syndrome. In the most extreme cases, aneuploidy can be lethal. The risk of nondisjunction taking place increases exponentially with the rising age of parent cells.

Typically disjunction is found during the process of meiosis.

At Which Phase Do Chromosomes Become Visible And Of What Do Chromosomes Consist?

Before chromosomes become visible during the prophase stage, the chromosomes are long strands called chromatin. The chromatin is tightly wound up into chromosomes.

Chromosomes are made up of DNA which is coiled tightly around histones. Histones are proteins which support the structure of the thread-like structures. Chromosomes are not visible under a microscope if the cell is not dividing, and it is not visible in the nucleus of the cell.

The short arm of a chromosome is the ‘p arm,' and the long arm is known as the ‘q arm.'

What Is Cytokinesis?

Cytokinesis is the process when cells physically divide. The cytoplasm of a parent cell splits into two daughter cells. This process starts during anaphase and doesn't stop until the telophase. Cytokinesis takes places during both mitosis and meiosis.

When and Why Will Cells Divide, How Many Chromosomes Will They Have, And What Triggers This Process?

Cellular division during mitosis may be triggered because of the need to replace or repair dead or lost cells or to grow in size. As part of the cell cycle, a cell will prepare to divide at interphase and begins its division process during mitosis.

A single cell will divide and reproduce copies of its DNA into two identical cells. The number of chromosomes will be the same as in the parent cell.

What Is The Difference Between A Diploid And A Haploid?

Diploid cells have a set of chromosomes from two different parents, with two homologous copies of each chromosome of their parents. Diploid cells reproduce by mitosis, and somatic cells are examples of diploid cells.

Haploid cells are created because of the meiosis process. Gametes or sex cells are a common type of haploid cells. Haploid cells only have one complete set of chromosomes.

Define Polyploidy And Aneuploidy?

When there is a variation in the number of chromosomes, it is described as being either aneuploidy, monoploidy, or euploidy. Depending on whether one part of a chromosome is lost, an entire set of chromosomes is lost, or one or more than one complete set of chromosomes is gained the term changes.

With chromosomes, conditions can either be double monosomic or double tetrasomic.

What Is An Allele And The Law Of Independent Assortment?

A gene is a single unit of information that is hereditary. Except in the case of some viruses, genes are made up of DNA which transmits traits. An allele is a genetic sequence which is a variant of a gene. When there are differences among copies of a gene, they are called alleles. At the locus of a gene, there are only two alleles present.

Gregor Mendel has been credited with our enlightened understanding about genetics, heredity, and what happens when there are variants in genetic transmission. According to Mendel's Law of Independent Assortment, a pair of alleles will separate independently when gametes are forming. Traits are transmitted to offspring independently.

The Law of Independent Assortment was formed on principles uncovered when Gregor Mendel conducted experiments creating dihybrid crosses between plants which had two different traits. As a result of Mendel's experiments, a ratio developed to reinforce this concept.

What Type Of DNA Damage Occurs When Cytokinesis And Mitosis Fail?

If a cell fails to separate during cytokinesis, it may have multiple nuclei.

During the prometaphase and metaphase stage, if a cell fails, it enters the G1 phase of a cell cycle, or it results in cell death. The checkpoints within the cell cycle help to regulate the process of cell division and will signal to different pathways if there is a failure.

Steps are automatically taken to prevent any damaged DNA from being reproduced or transmitted to a new generation of cells, to protect integrity.

When mitosis fails to carry out is process an abnormal number of chromosomes is created. To prevent continuous cell division, abnormal cells may be removed. A failure in mitosis typically activates cell death and consequent DNA damage.

What Are The Cell Checkpoints And What Are Their Functions?

Depending on if certain conditions are met cellular division may be inhibited, such as in the instance that growth hormones are released. When there is cellular growth, cells have to divide to prevent cell crowding.

If there is a release of specific hormones or a lack thereof, cell checkpoints may not allow the progression of a cell to the next stage in the cell cycle until there are viable conditions.

At the G1 checkpoint, any damage to DNA and relevant external stimuli are evaluated before a cell can move forward to interphase.

The G2 checkpoint is needed to make sure that all chromosomes have been replicated without any damaged DNA. Until this is assured, a cell will not be able to enter mitosis.

The M checkpoint is responsible for making sure every chromosome is attached to the spindle, and will not allow the separation of duplicated chromosomes if there is a problem.

Cell checkpoints are part of the eukaryotic cell cycle.

Additional Helpful Pointers

Before your quiz make sure that you can break down any pertinent information in easy to understand terms. However, be aware of the correct terminology and the sharp differences between mitosis and meiosis to reduce any unwanted confusion. Make sure to get enough sleep, eat well, and give yourself enough time to study the material before attempting to complete a quiz.

Don’t underestimate or disregard the power of drawing out your own diagrams to fully grasp the concept of each stage of mitosis. Visuals can have a stronger influence than reading words alone about the process.

7 Cell Raps To Help Memorize The Functions Of Cells

If you’re studying for a science test, one of the best ways to help remember the material is by setting to music! That’s right; cell raps can help you remember the names of the organelles located in each cell, as well as their functions.

We’ve rounded up our top seven picks for cell raps that we think you’re going to love.

 

via GIPHY

Best Cell Rap for Sixth-Graders: Cells Cells by Crappy Teacher

As YouTuber CrappyTeacher (Emily Crapnell) explains in her cell rap video, she created this video to help her sixth-grade science students learn the different parts of a cell. At over 5.7 million views, it seems that this cell rap has caught on with more than just Crapnell’s students! We can’t blame people for watching it; it’s catching and makes science–dare we say it?–fun!

“Today’s the day,” the rap begins; “let’s talk about the building blocks of life–cells that make us.”

The cell rap chorus covers some of the most vital parts of cellular biology. It explains that cells are made of organelles, and mentions cytoplasm, the nucleus (“controllin’ everything”), the membrane, the vacuole (“we can float around for hours”), and chloroplasts by name.

The next chorus explains that there are two different types of cells–animal and plant cells, while the final three stanzas are devoted to explaining in more details with each part of the cell does. “The cell membrane is the border patrol,” raps CrappyTeacher, and then later, “The mitochondria’s something every cell needs, breaking down the food and releasin’ energy.”

Over second thousand people have taken the time to comment on this cell rap. Many mention how they heard it years ago and still remember it, speaking to the catchy lyrics and the arresting beat. While designed for sixth-graders, the content is sophisticated enough that even college students report finding it helpful!

We also feel like it’s one of the best mixes of catchy lyrics and useful information, managing to find a good balance between repetition and new information. Plus, it provides a great video with very helpful images which will further solidify the information in your mind.

The rap can be viewed here or may be purchased.

Best Karaoke Option: The Cell Song by Glenn Wolkenfeld

The Cell Song, created and sung by Glenn Wolkenfeld, isn’t a cell rap–but it is a fantastic way to use the power of song to help commit the parts of a cell to memory! And with over two million views, we’re not the only people who think so.

The song is a folksy, bluesy tune where the singer asks what happens when he goes into a cell. “Who drives this bus,” sings Wolkenfeld, and then he “found myself talking to the boss, the nucleus.”

Unlike some of the other cell raps available, The Cell Song explains that chromosomes stores genetic information, the ribosomes make proteins, and the lysosome use enzymes to dissolve, and centrioles organize chromosomes into spindles.

Wolkenfeld also uses The Cell Song to explain how rigid cell walls allow plants to grow extremely tall, and the purpose of green in the plant cell. “I went into a plant cell, ‘why’s it so green?’” sings the artist. “‘Cause I make food from sunlight,’” answers a green chloroplast.

The video is filled with helpful drawings and diagrams to further illustrate each concept. Wolkenfeld, as we mentioned already, also offers a karaoke version, which is the same version, but instead of Wolkenfeld singing, the lyrics are on the screen.

The Cell Song, like Cells Cells by CrappyTeacher, has the ability to combine great video content with helpful, relevant information about cells.

You can find The Cell Song here, and the karaoke version here.

Best Song With Video: The Parts of a Cell Song by Jam Campus

The Parts of a Cell Song is a cell rap created by an organization called Jam Campus. It’s one of many Jam Campus creations; in fact, the YouTube channel creates educational videos on everything history to science to mathematics.

With over 54,000 views, The Parts of a Cell Song is catchy and well-loved. What we especially love, in addition to the self-made music, is the high quality illustrated video! Any time you can marry great visual images with catchy lyrics, you increase the likelihood of you remembering the information.

The Parts of a Cell Song gets right down to business, stating in its first line, “here’s what each cell contains, outer layer is the cell membrane.” The lyrics point out where cells get their energy (mitochondria), and what ribosomes do (help with protein synthesis).

We also appreciate this lyric, which helps to sum up the parts of a cell, something most cell raps don’t do:

Cell membrane, mitochondria, lysosomes and the ribosomesCytoplasm, nucleus, E.R. and Golgi body, and the nucleolus

​We especially appreciate how accurate the presented information is here (many cell raps mistakenly identify ribosomes as making proteins; however, they simply help in the assembly of polypeptides, chains of amino acids, which are the building blocks of protein).

Best for Repetitive Learning: The Cell Rap with Mr. Simons’ Fifth Grade Class

Mr. Simons and his fifth grade have teamed up to create another great cell rap, available on YouTube. This cell rap has approximately 468,000 views, and we understand why–out of all the cell raps we’re sharing today, this one is probably the most likely to get stuck in your head!

​Every song has to decide how to balance repetition with new information; as you’ll see later, some of the cell rap songs we’ve rounded up choose to focus on including as much data as possible. This rap, however, from Jake Simons, focuses on repetition.

In fact, we feel it focuses a little too much on repetition, but it’s still a great rap that will help cement many of the things you’re learning about cell biology into your memory.

​This five-minute rap features the cytoplasm, the nucleus, the membrane, the vacuoles, and the mitochondria of the cell. Here’s an example of a lyric:

“Just like us, the cell has energy. The mitochondria takes the food and puts it where it needs to be.”

Here’s another line from the cell rap, this one memorably explaining how the cell membrane works:

“There’s a thing called a membrane that holds it all in place so none of us will ever complain.”

​Is this the cell rap to turn to if you need to memorize complicated material? Probably not; but it is a great option for younger students or people who need just the basic parts of a cell!

​Best Use of Additional Resources: The Cell Song by Keith Smolinski

​The Cell Song was written and recorded by Dr. Keith Smolinski as part of a doctoral study to research how music can help students learn complex science concepts. In addition to The Cell Song, which features the parts of a cell, there are another nine songs sold in an album called Biorhythms: The Music of Life Science.

Songs in Biorhythms cover everything from cellular division, to the digestive tract, to the ecosystem. The song we’re featuring, The Cell Song, isn’t a cell rap, but it is well-performed, catchy, and interesting to listen to!

While the accompanying video doesn’t include images, it does utilize the lyrics on screen. In just two minutes and nineteen seconds, Dr. Smolinski manages to cover everything from the nucleus to the cell membranes.

In The Cell Song, listeners learn that the nucleus contains the genetic code, the mitochondria are the power plants of the cell, and the vacuoles store food and water. We also learn that the ribosomes make proteins, the Golgi bodies pack and ship the proteins, and the endoplasmic reticulum carries them.

Plus, the song teaches that lysosomes are janitors, cytoplasm is gel-like, and cell membranes help regulate what comes in and out of the cell.

​In the notes section of this video, Dr. Smolinski also explains that additional teacher’s resources are available on his website, including a Teacher’s Guide for The Cell Song. All of Dr. Smolinski’s resources are based on the National and State of Connecticut Science Standards, so you can be sure you’re getting accurate and helpful information.

Best Rap Alternative: Organelles Song by ParrMr

​ParrMr, a YouTube creator, has garnered over one hundred thousand subscribers thanks to her (or his!) ability to put science lyrics to popular songs. If you cringe over cells raps or want music you’re already familiar with, you can find videos on everything from Pangaea to the atmosphere to the planets.

ParrMr’s songs are set to hits like Forget You by Cee Lo Green, Toothbrush by D’NCE, and Jealous by Nick Jonas. The one we’re featuring here is Organelles Song, set to Counting Stars by OneRepublic.

The music is easy to remember if you’re already familiar with the song–our one complaint, however, is that the lyrics have very little repetition. This has the upside of packing a ton of information into the four-plus minute song, but if you’re trying to make sure the material sticks, this might be a downside.

​“Look inside a cell,” sings ParrMr, who created this song for his or her sixth-grade students, “and you will see…organelles have jobs, yeah, organelles have…jobs.”

​The next lines focus on how plant cell walls and cell membranes protect the line like a fence, letting the right things in and out. ParrMr covers vacuoles, lysosomes, the nucleus, chromatin, DNA, and ribosomes.

The final stanza explains proteins and their relationships to the endoplasmic reticulum, Golgi bodies, and cytoplasm. Mitochondria and chloroplasts are also mentioned.

​Organelles Song by ParrMr has racked up over 700,000 views, and for a good reason.

Runner-up Rap Alternative: Cells Song by ParrMr

Another much-loved option (four hundred thousand views!) by ParrMr, also for a sixth-grade classroom, this is another song about cells set to hit music. This one, called Cells Song, is set to Sail by AWOLNATION.

In it, ParrMr sings about cell membranes, cytoplasm, organelles, mitochondria, endoplasmic reticulum, ribosomes, and Golgi bodies.

“Cells cells cells cells cells,” he sings, before starting another chorus about vacuoles, the nucleus, and lysosomes.

​Here is the final stanza:

Capturing Sun’s energyChloroplasts in plants and treesAnd cell walls giving box-like shape, rigid

If you’re a fan of pop or dance music or are simply looking for a non-rap alternative to cell raps, this is a great option. It’s short on useful information, but what is included is presented appealingly, and will be likely to stick!

Thanks to these seven awesome cell raps, we have a feeling you’re going to ace your next quiz or test. We’d say good luck, but we don’t think you’ll need it!

Featured Image Source: Pixabay.com

Questions To Study For A Brain Anatomy Quiz In AP Biology

Questions To Study For A Brain Anatomy Quiz In AP Biology

human brain

image via: pxhere.com

Taking AP Biology? Have a brain anatomy quiz coming soon? We’ve got 17 questions to help you study for it, plus some clever tricks and tips for studying smarter, not harder!

Parts Of The Brain

One of the first things you should have to ace a brain anatomy quiz is a thorough grasp of the parts of the brain and each part’s function. Here are some of the questions you might expect:

1. Where Is The Cerebellum Located And What Does It Do?

The cerebellum is the part of the brain situated at the back of the head. It receives sensory information and regulates your motor movements. The cerebellum also controls balance and coordination, helping you to enjoy smooth movements.  

2. Which Part Of The Brain Processes Visual Information?

The occipital lobe lies underneath the occipital bone. It is part of the forebrain (you have two, technically; one at the back of each cortex) and is responsible for processing visual information. Here’s a helpful memory device: the “o” in occipital can remind you of the “o” in optometrist or ophthalmologist.

3. If A Person’s Frontal Lobe Is Injured, What Functions Might He Or She Lose?

The frontal lobe can be found in the front of the brain, in each cerebral hemisphere. A deep groove called the central sulcus separates it from the parietal lobe, and another groove called the lateral sulcus separates it from the temporal lobe. A part of the frontal lobe known as the precentral gyrus contains the primary motor cortex, which controls specific body parts’ voluntary movements.

 

The frontal lobe is responsible for reasoning, higher order thinking, and creativity, so if somebody’s frontal lobe is damaged, he or she could have difficulty making decisions and reasoning.

4. What Are The Gyrus And Sulcus And How Do They Help The Brain?

Gyrus are the ridges on the brain and sulcus are the grooves (also seen as furrows or depressions). Together, their up and down “motion” are responsible for the folded, “spaghetti” appearance of the brain.

 

They are, in fact, an extremely clever way of making the most of very limited space. The brain is limited to the area inside your cranium, but the folding of the brain tissue allows a much greater surface area for cortical tissue, allowing additional cognitive function even in a relatively small space.

 

The human brain begins as a smooth surface, but as the embryo develops, the brain begins to form the deep indentations and ridges we see in the adult brain.

5. What Part Of The Brain Controls The Primitive Parts Of Our Body?

human body with light bulb head

image via: pixabay.com 

Pons is the Latin word for bridge, and that’s exactly what the pons appears to do in the brain, as its physically connected to the brainstem. Like any good bridge, the pons contains neural pathways to move signals to the medulla, cerebellum, and thalamus.

 

Many of the nuclei contained inside the pons are responsible for relaying signals, as we’ve already described, but other nuclei play roles in primitive functions that we don’t normally consider being within our control, such as respiration, sleep, bladder control, and others.

6. What Is The Corpus Callosum?

The corpus callosum sits underneath the cerebral cortex. It’s about 10cm long and is a thick, tough bundle of fibers that connects the cerebral hemispheres (right and left), enabling them to communicate with each other.

 

It has over 200 million axonal projections, making it the largest white matter structure.

7. Which Part Of The Brain Is The Newest From An Evolutionary Perspective?

The cerebrum is the part of the brain that is outermost. In it, the brain can store memories, call upon senses, and establish self-awareness. High order functioning can also take place here and its known for being larger in musicians and left-handed individuals. It is also considered to be the most recent brain development.

8. How Many Lobes Is The Brain Comprised Of, And What Are Their Names And Functions? 

Inside the brain is found the occipital lobe (see question #2), the frontal lobe (see question #3), the parietal lobe, and the temporal lobe. The parietal lobe sits behind the frontal lobe and above the temporal lobe. It is where the body becomes self-aware and plays an important role in language processing.

 

The temporal lobe plays a role in the processing of sensory input, helping the brain to translate these inputs into meaning. If, for example, you smell apple pie and think of your grandmother, you have your temporal lobe to thank!

9. Which Part Of Your Brain Acts Like A Supercomputer?

human brain as supercomputer

image via: pixabay.com

The thalamus is the small organ at the very center of your brain that acts as a supercomputer or switchboard, relaying signals throughout the brain. It is one of the most important parts of the brain and regulates motor signals, sleep, and consciousness.

 

Closely related to the thalamus is the hypothalamus, which sits just underneath the thalamus and regulates the pituitary gland and homeostasis.

10. Which Part Of The Brain Helps You Sneeze? 

The medulla oblongata (medulla is Latin for “middle”), and the medulla oblongata is located on the brainstem close to the cerebellum. It is responsible for involuntary or autonomic processes, which include vomiting and sneezing. It also helps with breathing, cardiac functions such as heart rate, and blood pressure.

 The Central Nervous System

light bulb in a wooden surface

image via: pixabay.com

The central nervous system is another important subject likely to show up on a brain anatomy quiz. The questions below will help you better prepare.

11. What Is The Central Nervous System (CNS) Comprised Of? 

The brain and the spinal cord make up the CNS, which is protected by the skull and the spine’s vertebral canal. It is the command center of the entire body, regulating all activity and processing all sensory inputs.

 12. What Role Does The Midbrain Play In The CNS? 

smiling woman

image via: pixabay.com

The midbrain controls visual reflexes (including automatic eye movements, such as blinking and focusing). It also contains nuclei that link parts of the body’s motor system, including both cerebral hemispheres.

13. What Is A Neurotransmitter? 

A neurotransmitter is a chemical that a nerve fiber releases when a nerve impulse arrives. It diffuses across the junction or synapse so that the impulse may pass to the next nerve fiber, muscle fiber, or other structure. Both neurotransmitters and inhibitory neurotransmitters are found in the brain.

14. What Is The Difference Between Dopamine And Serotonin?

Dopamine and serotonin are both powerful neurotransmitters. Serotonin impacts your sleep, arousal, hunger, and mood, while dopamine impacts your brain’s pleasure and reward system, your learning and attention, and movement.

15. What Is Glutamate And Why Is It Important? 

Glutamate is the most abundant neurotransmitter found in the CNS; in fact, it accounts for more than 90% off all the synaptic connections in your brain! Some parts of the brain, including granule cells found in the cerebellum, rely on glutamate almost exclusively. Glutamate also plays a vital role in memory and learning.

16. Can You Name The Most Common Inhibitory Neurotransmitter In The Brain?

boy with different books

image via: pxhere.com

GABA (gamma-Aminobutyric acid) is the most common inhibitory neurotransmitter found in the brain. It is considered inhibitory because it helps to calm or reduce neuron excitability. This means it plays an important role in calming anxiety. It also is responsible for the regulation of muscle tone.

17. What Is The Neurotransmitter That Triggers Our Fight Or Flight Response?

The fight or flight response is also called the acute stress response or hyperarousal; it is a physiological reaction that occurs when the brain perceives an imminent threat. Epinephrine (also known as adrenaline) is the neurotransmitter most responsible for this response. It can signal an increase in blood flow to muscles and greater blood flow through the heart, among other things (this is why your heart starts to beat quickly when you’re afraid).  

The Quick Guide To Studying Smarter

If you’re reading this article, you’re already well on your way to preparing for your brain anatomy quiz, but here are a few more tips to help you get the most out of your time studying:

Get Lots of Rest

Sleeping instead of studying sounds counterintuitive, but without sleep, your brain will have a hard time committing what you’ve learned to memory. In fact, one of the best things you can do to prepare for a test or quiz is to get a good night’s sleep the night before!

Use Memory Devices

We’ve already hinted at a few tricks for helping your brain remember facts (did you notice them in the questions above?), but mnemonic devices and facts set to music help those boring facts stick much better than just rote memorization.

Setting the major parts of the brain to your favorite song, for example, can help pique your brain’s interest and increase emotional arousal, increasing your odds of remembering the information!

Finally, make it real. Drawing the brain, using models of the brain, or reading stories about people who have injured certain parts of the brain are all ways to make abstract concepts seem real–and make you more likely to remember them. Good luck!

 

8 Websites with the Best AP Practice Exams

 High school is a challenging time in everyone’s life. And for students enrolled in AP courses, the end of the year is particularly challenging. As high-achieving students gear up for long exams that offer the potential for early college credit, many students are searching high and low for reliable study materials.

One favorite way to practice for an important exam is by taking practice exams. But finding high-quality AP practice exams is challenging. That’s why we curated this list of websites for you. Whether you’re looking for AP Biology practice exams or one for AP Art History, these websites will help you in your quest for a good score.

Why You Should Take a Practice Exam

The best way to gauge how ready you are for an exam is by taking a practice test. While its best to drill yourself with a wide variety of study materials throughout the year, use of a full-length practice test will help you to prepare for the exam in a whole new way. In addition to helping you study, taking a practice exam can offer the following benefits:

  • Enables you to acclimate to the test format.
  • Relieves unwanted test anxiety.
  • Familiarizes you with test content.
  • Offers an opportunity to customize your study plan.
  • Gives testers a sense of readiness.

Practice exams are a helpful tool for getting yourself in tip-top test shape. But don’t forget to apply the knowledge you gain from taking practice tests. For example, if you come across the material in the practice test that you don’t understand, bring it up with your teacher as soon as possible.

girl studying

Source: Pexels.com

Below you’ll find a list of websites that offer AP practice exams in one format or another. Not all of them provide full-length tests, but all of them will help you get ready for your AP exams. Keep in mind, that AP tests are different each year and the practice questions you find online won’t necessarily be the ones you encounter on your exam.

8 Websites with the Best AP Practice Exams

College Board

image by: College Board

If you’re looking for a good starting place when it comes to mastering an AP exam, start with the official College Board website. There are many useful resources available on this website for students who are preparing for any of the AP Exams. In addition to study materials, the College Board website provides all of the information students need about the AP exams.

In addition to general information about each of the AP exams, the College Board website also offers sample questions for curious students. While a limited number of multiple choice sample questions are provided, a wide array of free response questions are typically available. Also, you’ll find a handful of student responses for comparison.

While this website doesn’t provide full-length practice exams, it is a great starting place. College Board is the official company behind all of the AP exams, and therefore the study materials they provide will be most like the AP tests.

APPracticeExams.com

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This website is an all-purpose study site from students preparing for AP exams. From AP Biology practice exams to class notes on Statistics, this website has a little something for everyone. It’s also worth noting that all of the resources on this web page are provided free of charge.

Unlike some websites that maintain their database of practice materials, AP Practice Exams provides links to the best free AP practice exams online. Students love using this site because it is easy to navigate and understand. Parents like this website because all of the materials are free.

While you can find a lot of resources through this web page, it does have its limitations. More specifically, the site is not backed by any testing or tutoring service. This drawback means that you’re on your own with the resources provided. However, for those who are self-driven, this site can be a treasure trove of information.

Also, it’s worth noting that the website is very low-key and doesn’t feature many stunning visual features or modern conventions. However, because the resources are all free, it’s a good option for many.

Albert

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Albert is a study and test-prep website designed to help students get the most out of the learning experience. Unlike the sites already mentioned above, the resources available through this website are not free of charge. However, they do offer a comprehensive program for preparing for many of the AP exams.

Pricing for the materials on this website varies by subject area, but for the most part, you can expect it to be relatively affordable. Unfortunately, it doesn’t seem that there are any concessions made for students who can’t afford the costs associated with using Albert.

Albert provides a variety of study materials including practice multiple choice questions, practice free response questions, and at least one full-length practice exam. Additionally, there are numerous study tips and testing tricks to help students make the most of test day. Albert also offers an overview of the core concepts that are tested in each subject.

This website features an attractive and easy-to-use interface that simplifies the study process. However, the fact that you must pay to use these study materials means that many students won’t be able to take advantage of this program. All in all, this is a good website for students whose parents have a little extra cash to spare.

Get A Five

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Get A Five is a web-based tutoring program that is available to students and teachers free of charge. However, unlike some other websites, this one is somewhat limited in scope. But, if your AP class is available, we highly recommend taking advantage of this valuable resource.

Unlike other programs, Get A Five offers a virtual study room, a diagnostic test, practice tests, and video-based lessons. Each program available in this online resource is customized to provide users with the ultimate learning experience.

Despite being limited to the few materials available, this website is an excellent resource for AP students in the classes offered. And, for a small fee, you can have your practice free response questions hand graded. We love that this resource doesn’t cost anything to use, but provides excellent value nonetheless.

Get A Five currently offers four courses for students preparing for the AP exam period. The subjects offered include AP Calculus AB, AP Biology, AP US History, and AP World History. While this selection is limited, it’s worth checking back from time to time to see if new courses become available later on.

High School Test Prep

Highschooltestprep

High School Test Prep is another free resource available for students preparing to take an AP exam. The materials available on this website are relatively limited but can prepare you for the general idea of how the test will be. However, it’s worth noting that this resource does not provide full-length exams. Also, it only covers multiple choice questions.

To help students understand the subject area they are testing over, each multiple choice question on this website gives a brief explanation of the correct answer. And while we wouldn’t recommend relying on this website alone, it serves as an excellent way to see where you stand.

After reviewing the materials on this website, you’ll be better prepared to formulate a study plan that will adequately prepare you for your upcoming test. Once you’ve studied the areas that are more difficult for you, use one or more of the other resources listed here to prepare yourself even more.

logo

image by: study.com

Study.com offers students a variety of materials for preparing for several different AP exams. They even provide several short practice exams to help you evaluate where you stand concerning the test you’ll be taking later in the school year.

In addition to the short practice tests they offer, study.com also offers test prep services. However, it’s worth noting that these services are not free of charge. Information on pricing is not disclosed without starting a “free trial” so explore these options carefully.

We like that there are several free practice tests available, but the lack of clarity when it comes to plans and pricing seems a bit dubious. Still, if you’re willing to spend a little money, it may be worth it to explore this option.

If you feel that you still need extra practice after thoroughly searching through these websites, consider visiting your local library. There, you may find practice books that contain additional practice questions or exams.

Keep in mind, not all study resources are free, and you should be extremely cautious when choosing how to spend your extra money. Also, always use caution when you have to input a credit card number online. And never purchase online materials without your parent’s permission.

With the resources listed above, you should be well on your way to finding the practice exam that’s right for you. Also, don’t forget that practice exams are only part of the study equation. Remember to brush up on necessary vocabulary and time management strategies as well.

Six Resources with the Best AP Textbook Prices

Advanced Placement classes were once limited to select groups of students, but today, these classes dominate the high school experience. During the 2016-2017 school year, 111,000 students in American schools took the computer science course with a growth of more than 54,000 students from the previous year. We’ve put together a list of excellent resources for finding the best AP Biology textbook prices including some brand-new publishers that focus on cutting the costs of AP courses.

Biology and other sciences are also on the rise. A total of 2.7 million students took five million AP exams according to College Board, the test designer and proctor.

Unfortunately, growth in enrolment hasn’t meant a decline in costs. While some low income students see their test fees covered, recent cuts from the Every StudentSucceedsAct mean that some students need additional dollars.

Finding financially accessible textbooks has never been more critical as more students prepare for more AP tests. Fortunately, these textbooks don’t have to break the bank and with greater student enrolment comes more options for new books.

Six Places to Find the Best AP Textbook Prices

Searching for your AP biology book and think you might get a better price? Check out these resources before placing your order.

Amazon

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image by: Amazon

Buying AP biology test books from Amazon means you have access to almost every brand and publisher imaginable including off-the-beaten-path books. You’re not only offered the most up-to-date editions of each book, but they come in various formats. Both comprehensive reviews and Cliff’s Notes versions of each book are available online.

Why buy Amazon?

Amazon offers excellent back-to-school prices and a simple returns policy. If you’re a Prime member, you’ll also benefit from free, fast shipping.

Additionally, Amazon hosts customer reviews that give you insight into the book. If you’re looking for complete coverage in specific areas or a particular learning style, the reviews section provides excellent coverage of what it’s like to use the book.

Finally, some books come in both used and new varieties as well as Kindle editions, so there are plenty of ways to save extra cash or even get more books.

Google Books

Google_Book

image by: Google books

Buying the digital version of AP books is a great way to save money and make test prep more accessible wherever you are.

Google Books offers a range of AP test prep e-books including AP Biology. Google’s library hosts most of the major test prep brands including:

  • Kaplan
  • Barron’s
  • CliffsNotes
  • The Princeton Review
  • McGraw Hill

There are also plenty of unknown authors that offer a different or cheaper way to study.

You can access Google Books on any device as long as you log into your Google account. You can even use them on your computer if you prefer a bigger screen. Visit the desktop version of the Google Play store for access.

Google Books also offers refunds on unread books. If you find digital versions don’t work for you or you’re one chapter into a book unsuited to your learning style, it’s possible to return it. Visit the My Account section the Google Play store and click the item you want to return.

You may return any e-book up to seven days after buying it. E-book rentals are final sales. If the e-book malfunctions, you may receive a refund within 65 days of the purchase date.

Textbooks.com

textbook.com

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Looking for an AP Biology textbook rather than test prep?

Visit Textbooks.com to search through the vast marketplace of competitively priced books. You’ll find new, used, and e-book versions of most of the primary textbooks all from different sellers.

Type “AP biology” into the search bar to find precisely what you need. When we last looked, 274 results were available and included:

  • Biology (AP 11thEdition) (Mader)
  • Cliff’s AP: Biology (2ndEdition)
  • SparkNotes Guide to AP Biology
  • Barron’s AP Biology
  • Campbell Biology, AP Edition
  • Cracking the AP Biology Exam 2017

Textbooks.com offers the best prices we’ve seen with some books.

While the prices can’t be beaten, it’s good to be wary of buying used books. While used books are ideal, an older book might miss something covered on the test. New books tend to include the latest edition of the test more precisely as well, which helps give you an edge.

eBay

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If one internet giant comes to mind for textbook purchases, it’s Amazon. But eBay is also an excellent resource for AP biology books. Much of what you’ll find on eBay falls under the category of gently used, but our searches showed that you’re more likely to get the very latest version of the book on eBay compared to other sites.

eBay was partly eclipsed by Amazon because it relied so heavily on seller’s ability to ship things in good time. Shipping was also previously based on zip codes. It quickly made up the bulk of the price on cheaper items.

Today, free shipping is standard on eBay items including on AP history books.

Why choose eBay over Amazon or another used book marketplace?

eBay demands more of a description of the book before posting. Amazon and other sellers tend to note whether the book is in excellent, good, or poor condition. On eBay, sellers indicate the state of the book, but many also describe any damage to the book such as any writing included in the book or if the cover is frayed.

Buying a New Book and Worried About the Price?

If the price of a textbook seems to good to be true, it often isn’t. Bookstores tend to sell U.S. versions of textbooks featuring hardcovers and quality materials. The international version, which is what is usually found significantly cheaper on eBay, is a softcover with cheaper paper. In most cases, the international version is a carbon copy of the same book. Some anomalies arise, but you are likely to see those in the seller reviews.

Regardless of where you buy, double check the edition to make sure it’s not a reprint. Fortunately, most AP course books include the date or version on the cover, so it’s easy to spot in the photos.

OpenStax

OpenStax

image by: openstax

Have you already looked at Barron’s, the Princeton Review, Cliff Notes, and others without finding much success?

AP biology students now have a new option: OpenStax.

OpenStax is a non-profit textbook developer from Rice University. Their goal is to improve access to AP tests, college, and education generally by providing open-licensed college textbooks. Because these books are open-license and OpenStax isn’t out to make money, you’ll receive a high quality, current book for far less money than traditional textbooks.

OpenStax started out providing STEM subjects including biology. Today, they are available for many AP topics including:

  • Biology
  • Physics
  • Macroeconomics
  • SparkNotes Guide to AP Biology

These books aren’t just test prep books. They’re suitable for students taking AP or college courses to prepare for the tests.

The OpenStax Biology for AP® Courses book covers all the requirements of the standard two-semester AP course. It meets core concepts and foundational research and uses the evolutionary lens mandated by AP. The company designed its book not just to meet but exceed the requirements set by College Board, which makes it an essential learning book and an excellent companion to AP study books for those working independently.

HOW MUCH WILL YOU PAY FOR THESE HIGH-QUALITY BOOKS?

Students are expected to pay nothing. These books are free and licensed under Creative Commons, which means everyone has access to them.

Before you worry about quality, don’t. Each book is written by experts in their field. The content is sourced and vetted by peer reviewers, just like the traditional course books you’d otherwise buy.

In 2016 alone, 392,000 students used these books to save a good amount of money. So, head over to OpenStax, and give them a try.

Pearson

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Pearson is an industry-leading education company that publishes books known for their academic rigor. Their AP® Honors & Electives series is no different.

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Are You Ready for Your AP Exam?

Barron's AP Biology, 6th Edition

AP classes aim to prepare you for the exam, but the help of test prep books and a good textbook are invaluable to the process. While exam prices continue to climb, test prep books remain competitive, and some quality materials are now free to all student.

What books would you recommend for scoring a 5 on an AP Biology exam? Share your favorite study materials and tricks in the comments below.

Earthworm Anatomy and Dissection Guide

Earthworm Dissection and Earthworm Anatomy

Pictures: Modern Biology, Holt

The following is a classification of a species in the earthworm family Lumbricidae. This common species is Lumbricus terrestris also known as the night crawler or dew worm. In this article, we will cover earthworm anatomy and an introduction on dissecting an earthworm. 

Phylum –
Class –
Family –
Genus –
Species –
Annelida
Oligochaeta
Lumbricidae
Lumbricus
terrestris

Objectives:

 

In this earthworm dissection guide, you will learn to:


• Describe the appearance of various organs found in the earthworm.
• Name the organs that make up various systems of the earthworm.

Materials:
Safety goggles, dissecting pins, gloves, forceps, lab safety apron, scissors, paper towel, scalpel, water, dissecting probe, preserved earthworm, hand lens, dissection tray.

Purpose:
In this lab, you will dissect an earthworm in order to observe the external and internal structures of earthworm anatomy, whilst following the all-important lab safety procedures.

 

This guide is perfect for students in colleges or universities. 

 

 

Background:


Among the most familiar invertebrate animals are the earthworms, members of the phylum Annelida. The word annelida means “ringed” and refers to a series of rings or segments that make up the bodies of the members of this phylum. Internally, septa, or dividing walls, are located between the segments. External segments are called metameres. There may be more than 100 segments in an adult worm. The clitellum is a swelling of the body found in sexually mature worms and is active in the formation of an egg capsule, or cocoon. This is the earthworm reproductive organ. Eggs are produced in the ovaries and pass out of the body through female genital pores. Sperm are produced in the testes and pass out through tiny male genital pores. During mating, sperm from one worm travel along the sperm grooves to the seminal receptacles of another worm. Fertilization of the eggs takes place outside the body as the cocoon moves forward over the body, picking up the eggs of one worm and the sperm of its mate. The pumping organs of the circulatory system are five aortic arches. Circulatory fluids travel from the arches through the ventral blood vessel to capillary beds in the body. The fluids then collect in the dorsal blood vessel and reenter the aortic arches. The earthworm takes in a mixture of soil and organic matter through its mouth, which is the beginning of the digestive tract. The mixture enters the pharynx, which is located in segments 1–6. The esophagus, in segments 6–13, acts as a passageway between the pharynx esophagus and the crop. The crop stores food temporarily. The mixture that the earthworm ingests is ground up in the gizzard. In the intestine, which extends over two-thirds of the body length, digestion and absorption take place. Soil particles and undigested organic matter pass out of the worm through the rectum and anus. The nervous system consists of the ventral nerve cord, which travels the length of the worm on the ventral side, and a series of ganglia, which are masses of tissue containing many nerve cells. The nerve collar surrounds the pharynx esophagus and consists of ganglia above and below the pharynx. Nervous impulses are responsible for movement and responses to stimuli. Each segment contains an enlargement, or ganglion, along the ventral nerve cord. Excretory functions are carried on by nephridia, which are found in pairs in each body segment. They appear as tiny white fibers on the dorsal body wall. The earthworm has no gills or lungs. Gases are exchanged between the circulatory system and the environment through the moist skin.

earthworm anatomy

 

External Earthworm Anatomy

 

What is the external anatomy of an earthworm?

 

The external body of an earthworm is well adapted for living in the soil, similar to the external structure of other insects. The front or head of the worm is called the anterior. The very first section of the anterior contains the mouth and prostomium. The prostomium is a kind of lip which is located on the front of the mouth. Earthworms lose moisture and breathe via their skin. They have light-sensitive cells across their external structure, which are scattered around the skin. These cells give earthworms the ability to detect changes in lighting, and these cells are also sensitive to chemicals and touch. The body is separated in segments which resemble rings. Each segment has a number of bristly hairs attached to it, which helps the earthworm to move around. On mature earthworms, you will find a saddle or glandular ring called a clitellum. When an earthworm has mated, the clitellum will secrete a sack of eggs. The final segment of an earthworm contains the anus which is where waste is secreted. 

 

Dissection Guide:


1. Put on safety goggles, gloves, and a lab apron.

2. Place earthworm in the dissecting tray & rinse off the excess preservative. Identify the dorsal side, which is the worm’s rounded top, and the ventral side, which is its flattened bottom. Turn the worm ventral side up, as shown in the earthworm anatomy diagram below.

earthworm anatomy

3. Use a hand lens as you observe all parts of the worm, externally and internally. Locate the conspicuous clitellum, a saddle-like swelling on the dorsal surface.  The clitellum produces a mucus sheath used to surround the worms during mating and is responsible for making the cocoon within which fertilized eggs are deposited.  The anterior of the animal is more cylindrical than the flattened posterior and is the closest to the clitellum.  The ventral surface of the earthworm is usually a lighter colour than the dorsal surface.  The mouth is located on the ventral surface of the first segment while the anus is found at the end of the last segment. Find the anterior end by locating the prostomium (lip), which is a fleshy lobe that extends over the mouth. The other end of the worm’s body is the posterior end, where the anus is located.

earthworm anatomy

4. Locate the clitellum (the reproductive organ), which extends from segment 33 to segment 37. Look for the worm’s setae, which are the minute bristle-like spines located on every segment except the first and last one. Run your fingers over the ventral surface of the earthworm’s body.  You should be able to feel bristle-like setae used for locomotion

5. Refer again to the diagram of the ventral view of the worm to locate and identify the external parts of its reproductive system. Find the pair of sperm grooves that extend from the clitellum to about segment 15, where one pair of male genital pores is located. Look also for one pair of female genital pores on segment 14. There is another pair of male genital pores on about segment 26. Try to find the two pairs of openings of the seminal receptacles on segment 10.   Note: These openings are not easy to see.

 

Internal Earthworm Anatomy

 

What is the internal anatomy of an earthworm?

 

At the very front of an earthworm, you will find the pharynx. Earthworms push the pharynx from inside their mouths to grab hold of things. They pull food into their mouths and then soak it in saliva. As earthworms don’t have teeth, they have to use strong muscles called a gizzard, along with sand and soil, to grind up the food they are eating. Once the food has been fully ground up, it travels to the intestines where it is further broken down so that it can be absorbed. The majority of earthworms have five aortic arches which are like hearts and these move around their bodies. A large blood vessel runs across the top of the earthworm and this is called the dorsal blood vessel. This vessel contracts and pumps blood around to the aortic arches. There is a further blood vessel on the lower side of the earthworm which is called the ventral blood vessel. An earthworm has a very simple nervous system. A ventral nerve cord which runs the entire length of its body connects to the cerebral ganglion, which is an earthworm’s brain. Each segment is connected to the cord so that they can sense light and touch, and can move. Each segment is also wrapped in circular muscles, which contract to help the earthworm move. 

 

 

 

Continued: Dissection Procedure

 

Hint: Position your preserved earthworm dorsal side up and pin it down through the first segment and then again further back behind the clitellum.  Cut a slit in the dorsal surface near the posterior pin.  Using fine scissors extend the cut forward to the first segment.  Be careful not to cut too deep as to affect the internal organs.  Starting at the first segment, cut the septa (thin membranes) that internally divide the segments, so the skin can be laid flat.  Use additional pins to hold the integument open and expose the internal organs.  Continue to lay the skin back until you have uncovered a centimeter or so of the intestine.

6. Turn the worm dorsal side up. Using a scalpel and scissors, make a shallow incision in the dorsal side of the clitellum at segment 33. CAUTION: Scalpels and scissors are very sharp. Report any cuts to your teacher. Using the forceps and scalpel, spread the incision open, little by little. Separate each septum from the central tube using a dissecting needle, and pin down each loosened bit of skin. Continue the incision forward to segment 1.

7. Use the diagram below to locate and identify the five pairs of aortic arches, or hearts. Then find the dorsal blood vessel. Look for smaller blood vessels that branch from the dorsal blood vessel.

 

earthworm anatomy

earthworm anatomy

earthworm anatomy

earthworm anatomy

Digestive System

The earthworm is an example of a foraging herbivorous annelid, obtaining food by eating its way through the soil and extracting nutrients from the soil as it passes through the digestive tract.

Hint: Starting at the anterior end, locate the muscular pharynx (food ingestion).  This is followed by a tube-like esophagus which terminates in a crop (the wider organ) which serves as a storage stomach.  Posterior to the crop you will find the gizzard.  Gently press on the crop and gizzard to test their firmness.  While the crop is soft and thin, the gizzard is muscular (soil is ground up and churned within the gizzard).  The gizzard is followed by a long intestine in which both digestion and absorption occur.  Undigested material is voided through the anus.

8. Locate the digestive tract, which lies below the dorsal blood vessel. Refer to the diagram above to locate the pharynx, esophagus, crop, gizzard, and intestine.

earthworm anatomy

9. To find organs of the nervous system, push aside the digestive and circulatory system organs. Use the diagram below to locate the ventral nerve cord. Trace the nerve cord forward to the nerve collar, which circles the pharynx. Find one pair of ganglia under the pharynx and another pair of ganglia above the pharynx. The ganglia above the pharynx serve as the brain of the earthworm.

earthworm anatomy

earthworm anatomy

10. The worm’s excretory organs are tiny nephridia. There are two in every segment. Use the preceding diagram to locate some nephridia.

earthworm anatomy

11. Use the diagram below to locate and identify a pair of ovaries in segment 13. Look for two pairs of tiny testes in segments 10 and 11. To find these organs, you will again have to push aside some parts already dissected.

earthworm anatomy

earthworm anatomy

earthworm anatomy

12. Dispose of your materials according to the directions from your teacher in your college or university.

13. Clean up your work area and wash your hands before leaving the lab.

Earthworm worksheet Earthworm facts

BACK

Everything You Need to Know About the Calvin Cycle

The Calvin Cycle occurs during photosynthesis and consists of light independent redox reactions that convert carbon dioxide into glucose. This conversion happens in the chloroplast, or more specifically the stroma of the chloroplast. The chloroplast region is an area between the thylakoid membrane and the inner membrane of the organelle which is typically located in the leaves of plants.

This cycle used to create carbon sugars, mostly, was discovered by Melvin Calvin, Andrew Benson, and James Bassham in 1950 at the University of California. The used radioactive material to trace the pathways carbon atoms took during the carbon fixation step in plant life.

You've probably heard the Calvin Cycle called a few other names including the CBB Cycle, C3 Cycle, and dark reactions to name a few.

This process of carbon fixing by plants is essential to all life on the planet. Most new organic growth stems from plants converting carbon to sugars either directly or indirectly. Other plants, or animals, can use these sugars to forms more complex sugars and amino acids when they consume them. It all stems from little plants working day and night to capture light and water.

A Technical Take on the Calvin Cycle

The Calvin Cycle

The Calvin Cycle occurs during photosynthesis and is repeated until it forms a glucose molecule. Photosynthesis goes through two stages to create food and building materials for plants to grow. During the first stage, chemical reactions from light produce ATP and NADPH. The second stage is when the Calvin Cycle takes place. In this stage, carbon dioxide and water get converted to organic materials like glucose. These reactions are called dark reactions which confuses people, but they do not take place at night.

The short explanation of the Calvin Cycle is that it begins with carbon fixation. Carbon dioxide molecules are plucked out of the air to produce glyceraldehyde 3-phosphate. RuBisCO, an enzyme found abundantly around the planet, brings on the carboxylation of a 5-carbon compound and provides a 6-carbon compound that halves itself form two 3-phosphoglycerate. The enzyme phosphoglycerate kinase uses the phosphorylation to create biphosphoglycerate.

Next, the enzyme glyceraldehyde 3-phosphate dehydrogenase uses the reduction of biphosphoglycerate by NADPH. This is called the reduction reactions. Eventually, when the cycle ends, the reactions and reductions produce one glyceraldehyde 3-phosphate molecule per every three carbon dioxide molecules.

That’s a lot of massive words. What that means is the plant uses light and water to convert carbon dioxide into nutrients and oxygen. It takes six turns on the Calvin Cycle for the plant to produce a single glucose molecule. Now that we simplified the process, let's look at the chemical equation for the Calvin Cycle:

3 CO2 + 6 NADPH + 5 H2O + 9 ATP → glyceraldehyde-3-phosphate (G3P) + 2 H+ + 6 NADP+ + 9 ADP + 8 Pi (Pi = inorganic phosphate)

The Simplified Function of the Calvin Cycle

Simplified-Calvin-Cycle-diagram

How plants create sugar from sunlight, water, and carbon dioxide is complicated as you probably noted from the previous section. However, plants toil away day and night creating glucose, starch, and cellulose so they can grow. The Calvin Cycle plucks carbon molecules right out of the air and creates new plant growth.

The Calvin Cycle is vital to every ecosystem, and it reaches far beyond the plants using it. Plants are the building blocks of all the food in any ecosystem. Herbivores eat plants for energy and growth while carnivores eat herbivores for the same reasons. In the end, everything goes back into the ground and plants start the process all over again.

If plants stopped all their hard work tomorrow, it would only take a few days for animals to start feeling the effects and starving. Herbivores lose their food right away. Carnivores would follow behind the herbivores. Plants make most of the basic building blocks we all need to continue life as we know it. Without their hard work, we’d all be doomed.

While plants are supplying us with the building blocks, we need to continue living, and they help out the environment in other ways. Because the Calvin Cycle depends on carbon dioxide, plants indirectly play a role in regulating carbon dioxide and other gases proven to be harmful to the atmosphere. Plants perform an essential role in helping us clean the air we breathe.

The Calvin Cycle Step by Step

Calvin Cycle step by step

Carbon fixation is the first step. We explained it in brutal technical detail above, but let’s look at it in simpler terms in this section. A carbon dioxide molecule is plucked from the air and combined with a five-carbon acceptor molecule called ribulose-1,5-bisphosphate, or RuBP for short. The result is a six-carbon molecule.

The six-carbon molecule is split in half to form a set of new carbon molecules called 3-phosphoglyceric acid, or 3-PGA for short. The new three-carbon molecules are catalyzed by an enzyme called RuBisCo. This creates the simple sugar molecules the Calvin Cycle needs for stage two. On a side note, because it is used by every plant during photosynthesis, the RuBisCo enzyme if the most common catalyst on Earth. The result of this step is passed on to the next phase.

Step two of the Calvin Cycle is called the reduction step. The 3-PGA molecules created in the carbon fixation step are used in phase two to develop glyceraldehyde-3 phosphate or G3P for short. G3P is a simple sugar. This process uses energy and reactions captured during light-dependent stages of photosynthesis.

This step is called the reduction step because electrons are stolen from molecules created during photosynthesis and given to our new sugars. In chemistry, when you take electrons from a molecule, it's called a reduction hence the name of this stage. Technically, the electrons are donated and not taken. Taking electrons by force is called oxidation, and that's not what happens in this stage.

At this point, our plant has created sugar it can store for a long time and use for energy. Anything that eats this plant gets to take advantage of these sugars as well including humans. The plant may choose to use these stored molecules to form new plant materials or repair itself, but that’s not part of the Calvin Cycle so we won’t get into it. This is the end of the sugar-producing phase of the Calvin Cycle.

The final stage of the Calvin Cycle is called the regeneration step. Some of the G3P are held back and not used to make sugars. Instead, they are used to revitalize the five - carbon compound the Calvin Cycle needs to start the process over again. It takes six carbon molecules to make glucose, so plants have to go through the Calvin Cycle six times to make one glucose molecule.

Once the plant has completed this cycle six times, the Calvin Cycle ends and begins again. So, technically, the Calvin Cycle is all three steps done six times each. Plants repeat this process over and over during daylight hours. At night they continue to work making various compounds that don’t require light. This makes plants the most efficient lifeforms on the planet.

Bonus Information About Plants and Their Internal Food Factories

plants

We usually consider waste products bad or at least not edible. However, we need the waste materials plants to produce to survive. An essential waste, or by-product, plants produce is oxygen. While plants are using water and carbon dioxide to make sugars, they release oxygen into the air around them as a waste product.

The delicious fruits and vegetables we all enjoy get most of their flavor from the carbon sugars plants store for energy. From the crunchy stalk of the celery plant to the succulent meat of the peach, plants developed all using just carbon dioxide, water, sunlight, and a few minerals leeched from the soil. I think we can assume these tasty treats are little gifts from the plant kingdom.

The tiny organelles called chloroplasts on the surface of a plant’s leaves can move. Ok, they can’t move individually, but in many plants, they can turn the leaf, so it gets better exposure to sunlight. These plant-based solar cells help capture sunlight so being able to point yourself in the sun makes sense. Some plants take it to another level and bend their stalk or branches to help reach the sunlight.

Some Final Notes

photosynthesis diagram

The fantastic plants we ignore all around us are vital to our survival. They use energy from the Sun in little energy reactors called chloroplasts to do all sorts of cool things. If you glance at the bigger picture and oversimplify it, plants take light from the Sun and turn it into carbon sugars they can store for long periods of time. We could call them solar powered batteries if we want to be humorous about the process.

Plants pitch in and help everywhere they can from cleaning the air to enriching the soil they grow in for the next plants. Plants give us so many things from apples to steak. Without plants toiling away at the bottom of the food chain, nothing in the top of the food chain could survive. Every food we consume comes from plants either directly or indirectly.