## Genetic Problems Solutions Campbell Ch14

Genetics Problems Campbell
1. A man with hemophilia (a recessive , sex-linked condition has a daughter of normal phenotype. She marries a man who is normal for the trait. What is the probability that a daughter of this mating will be a hemophiliac? A son? If the couple has four sons, what is the probability that all four will be born with hemophilia?

Solution

2. Pseudohypertropic muscular dystrophy is a disorder that causes gradual deterioration of the muscles. It is seen only in boys born to apparently normal parents and usually results in death in the early teens. (a) Is pseudohypertrophic muscular dystrophy caused by a dominant or recessive allele? (b) Is its inheritance sex-linked or autosomal? (c) How do you know? Explain why this disorder is always seen in boys and never girls.

Solution

3. Red-green color blindness is caused by a sex-linked recessive allele. A color-blind man marries a woman with normal vision whose father was color-blind. (a) What is the probability that they will have a color-blind daughter? (b) What is the probability that their first son will be color-blind? (Note: the two questions are worded a bit differently.)

Solution

4. A wild-type fruit fly (heterozygous for gray body color and normal wings was mated with a black fly with vestigial wings. The offspring had the following phenotypic distribution: wild type, 778; black-vestigial, 785; black-normal, 158; gray-vestigial, 162. What is the recombination frequency between these genes for body color and wing type.

Solution

5. In another cross, a wild-type fruit fly (heterozygous for gray body color and red eyes) was mated with a black fruit fly with purple eyes. The offspring were as follows: wild-type, 721; black-purple, 751; gray-purple, 49; black-red, 45. (a) What is the recombination frequency between these genes for body color and eye color? (b) Following up on this problem and problem 4, what fruit flies (genotypes and phenotypes) would you mate to determine the sequence of the body color, wing shape, and eye color genes on the chromosomes?

Solution

6. A space probe discovers a planet inhabited by creatures who reproduce with the same hereditary patterns as those in humans. Three phenotypic characters are height (T = tall, t = dwarf), hearing appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures were not “intelligent” Earth scientists were able to do some controlled breeding experiments, using various heterozygotes in testcrosses. For a tall heterozygote with antennae, the offspring were tall-antennae, 46; dwarf-antennae 7; dwarf-no antennae 42; tall-no antennae 5. For a heterozygote with antennae and an upturned snout, the offspring were antennae-upturned snout 47; antennae-downturned snout, 2; no antennae-downturned snout, 48: no antennae-upturned snout 3. Calculate the recombination frequencies for both experiments.

Solution

7. Using the information from problem 6, a further testcross was done using a heterozygote for height and nose morphology. The offspring were tall-upturned nose, 40; dwarf-upturned nose, 9; dwarf-downturned nose, 42; tall-downturned nose, 9. Calculate the recombination frequency from these data; then use your answer from problem 6 to determine the correct sequence of the three linked genes.

Solution

8. Imagine that a geneticist has identified two disorders that appear to be caused by the same chromosomal defect and are affected by genomic imprinting: blindness and numbness of the limbs. A blind woman (whose mother suffered from numbness) has four children, two of whom, a son and daughter, have inherited the chromosomal defect. If this defect works like Prader-Willi and Angelman syndromes, what disorders do this son and daughter display? What disorders would be seen in their sons and daughters?

Solution

9. What pattern of inheritance would lead a geneticist to suspect that an inherited disorder of cell metabolism is due to a defective mitochondrial gene?

Solution

10. An aneuploid person is obviously female, but her cells have two Barr bodies. what is the probable complement of sex chromosomes in this individual?

Solution

11. Determine the sequence of genes along a chromosome based on the following recombination frequencies: A-B, 8 map units; A-C, 28 map units; A-D, 25 map units; B-C , 20 map units; B-D, 33 map units.

Solution

12. About 5% of individuals with Downs syndrome are the result of chromosomal translocation. In most of these cases, one copy of chromosome 21 becomes attached to chromosome 14. How does this translocation lead to children with Down syndrome?

Solution

13. Assume genes A and B are linked and are 50 map units apart. An individual heterozygous at both loci is crossed with an individual who is homozygous recessive at both loci. (a) What percentage of the offspring will show phenotypes resulting from crossovers? (b) If you did not know genes A and B were linked, how would you interpret the results of this cross?

Solution

14. In Drosophila, the gene for white eyes and the gene that produces “hairy” wings have both been mapped to the same chromosome and have a crossover frequency of 1.5%. A geneticist doing some crosses involving these two mutant characteristics noticed that in a particular stock of flies, these two genes assorted independently; that is they behaved as though they were on different chromosomes. What explanation can you offer for this observation?

Solution

BACK

## Campbell Chapter 14 Gen Prob 1

Molecular Genetics: Problem 1
A man with hemophilia (a recessive , sex-linked condition has a daughter of normal phenotype. She marries a man who is normal for the trait. What is the probability that a daughter of this mating will be a hemophiliac? A son? If the couple has four sons, what is the probability that all four will be born with hemophilia?

Genotypes:

A man with hemophilia is XhY where h = hemophilia gene and H = the normal gene.
Any daughter with normal phenotype whose father has hemophilia will be a carrier.

Her genotype must be:

XhXH and NOT XHXH
We can use a Punnett square to show the probability of a daughter or son having hemophilia.

daughter x normal man
XhXH x XHY

A. If the daughter marries a normal male the probability of a daughter having hemophilia is zero.

B. About 50% of male children would have hemophilia (Boxes 2 and 4 above)

C. The probability that all 4 sons have inherited hemophilia would be: 1/2 x 1/2 x 1/2 x 1/2 or 1/16.

BACK

## Genetic Disorder Project Presentation

You have been challenged to incorporate your knowledge about cells, cell division, genetics, and DNA to research and present on a specific genetic disorder. You have already completed your basic study about the ideas of genetics and mutations. Now with the information that you have you are being asked to research a specific genetic disorder and give an oral presentation along with creating either a PowerPoint or poster to explain the genetic disorder.

should include the following points.

• What is the name of the disorder and what is the history behind the disorder? Who discovered it or/and who have done research on the disease?
• How is the disorder diagnosed? How does a person receive the disorder? Is it sex-linked? Is it a mutation? Is it due to heredity?
• You will need to find out all of the signs and symptoms of the given disorder and share these with the class.
• What types of treatment there are for the disorder?
• Include a suggested list of readings and/or Internet sources that may be of interest to the class.
• You are encouraged to share any other information that you feel is relevant that you feel is important for others to know about the genetic disorder.
 List of possible Genetic Disorders to Present: Achondroplasia (Dwarfism) Albinism Adrenal hyperplasia Autism/ Asperger syndrome Cystic Fibrosis Down Syndrome (Trisomy 21) Duchenne Muscular Dystrophy Familial Dysautonomia Gardner syndrome (intestinal polyposis) Gaucher’s Disease Hemophilia Huntington’s Disease Jacobsen Syndrome Klinefelters Syndrome Klippel-Feil Syndrome Leukodystrophy Lou Gehrig’s Disease (ALS) Marfan Syndrome Moebius Syndrome Polycystic Kidney Disease Progeria Proteus Syndrome Retinoblastoma Rett’s Syndrome Spinocerebellar Ataxia Tay-Sachs Disease Tourette Syndrome Turner Syndrome
 List of internet resources that may be helpful to you in creating your presentation:

Yahoo – Genetic Disorders http://dir.yahoo.com/Health/Diseases_and_Conditions/Genetic_Disorders/.
Site explains several different disorders and contains links to all of the different types of genetic disorders.

Genetic & Rare Conditions Sitehttp://www.kumc.edu/gec/support/.
links to different types of disorders in alphabetical order.

What can our chromosomes tell us? http://biology.about.com/science/biology/gi/dynamic/offsite.htm?site=http://gslc.genetics.utah.edu/.
A site that talks about karyotyping of genotypes.

Genetic Disorder Library
http://learn.genetics.utah.edu/units/disorders/whataregd

A basic genetic glossary.

Genetics Education Center http://www.kumc.edu/gec/.
Seeks to help educate people about genetics.

The National Human Genome Research Institute http://www.nhgri.nih.gov/.
Explains about the human genome project.

Department of Energy – Human Genome Project Information http://www.ornl.gov/hgmis/.
Provides a lot of information about the human genome project.

A Gene Map of the Human Genome http://www.ncbi.nlm.nih.gov/science96/.
You can see the mapping of several different chromosomes found within the body.

Learning about the Human Genome Project and Genetics through the World Wide Web http://www.kumc.edu/gec/hgpwww.html.
Looks at the ethical issues of genetic research.

Understanding Gene Testinghttp://www.accessexcellence.org/ae/AE/AEPC/NIH/index.html.
This site talks of how genes are linked to disease and how a gene creates a genetic disorder.

Basics of DNA Fingerprintinghttp://www.biology.washington.edu/fingerprint/dnaintro.html.
Explains the basic understanding of DNA fingerprinting.

What is Genetic Testing? http://www.lbl.gov/Education/ELSI/Frames/genetic-testing-f.html.
Shows the basics of genetic testing and talks about the ethical issues of that happen due to genetic testing.

 Rubric for Evaluation of Genetic Disorder Presentation.
 Beginning 5 points Developing 10 Points Accomplished 15 Points Exemplary 20 Points Total Score Oral Presentation Quality of Information Bare minimums have been accomplished. Little understanding about the genetic disorder delivered in oral presentation. Could only read slides with no further understanding. Minimums plus slight extras added. Answered questions from the intro and at least one question posed to them in the process section. All information present and complete. Some problems with flow and delivery. Shows more or less some understanding of knowledge – has minor flaws. Information is well thought out, flows well, all information is completed, Appears to have been practiced, knowledge shown. Bibliography Amount of additional Information for reading and websites found and presented no additional reading lists or websites provided or presented in bibliography. At least 2 web sites or books accessed and verified in presentation and presented in bibliography. At least 4 web sites or books accessed and verified in presentation and presented in bibliography. At least 6 web sites or books accessed and verified in presentation and presented in bibliography. Organization of presentation Random information is presented Disorganized at times. Organized Organized effectively with easy understanding. Use of class time working on project Majority of class time was wasted. Half of class time was wasted. Little class time was wasted. No class time was wasted. Overall Multimedia Presentation Disorganized Not Completed Missing Key Component Questions no graphics. Spelling errors present presentation has some flow to it but is choppy. Easily understood by all. Includes graphics and data tables of information retrieved. Neatly done, organized, proper spelling, allparts included,above and beyond effort. Information that is presented is aesthetically pleasing to the eye. Link to printable rubric in word document format Link to Bibliography Citation Machine TOTAL SCORE

## Writing Lab Notebook Reports

REVISED LAB REPORTS

LAB REPORT RUBRICS

## General Instructions:

1. All labs must be written in pencil and be submitted to the teacher in a spiral notebook.
2. Always use third person (NO personal pronouns — me, I, you, we, etc.) when writing all parts of a lab report. (USE HE, SHE, THEY, THEIR, THEM, ETC.
3. The following things should be written clearly in marker on the front cover — “Subject” Lab Notebook, teacher name, student name, period.
4. Number each page of the spiral notebook in the lower right hand corner.
5. On Page 1, write the subject, year, student name, class period, and teacher name.
6. Page 2 should have “Table of Contents” written at the top and two columns, one for “Page” and the other for “Lab Title”.
7. Begin writing the first lab on page 3 of you notebook. DO NOT WRITE ON THE BACK OF YOUR PAPER!
8. SKIP A LINE BETWEEN EVERY SECTION!
9. TITLE and UNDERLINE each section & then begin writing on the NEXT LINE!

## Your lab report should be written using the following format: (Be sure to left align & underline headings)

Title (center on top line; on the right of line 2, put date & lab #)
The title should indicate clearly & concisely the subject and scope of the report.

Introduction – 20 points (PARAGRAPH FORM)

• The introduction should give background information about the experiment.
• It should also state the purpose of the investigation.
• This section will be two or more paragraphs in length.

Hypothesis – 20 points (SINGLE SENTENCE)

• The hypothesis should be a single statement telling the exact thing you are trying to prove in your experiment.
• NEVER write this statement using “first person”. Write the hypothesis in past tense (third person.)

Materials – 5 points (SINGLE SENTENCE)

• This section should be written in sentence form and name all of the materials and equipment used.
• Be sure to include specific amounts and concentrations of chemicals used.
• Start the statement, “The materials used include _____, _____, etc.”

Methods (Procedure)- 5 points (STEPS; NUMBER)

• This section includes the step-by-step procedures used.
• The procedure should be so thorough that someone else could use your listed materials and procedures to conduct the same experiment and get the same results.

Results (Data & Questions) – 20 points

• All data should be collected and organized in a logical order. Results should be illustrated as charts, tables, graphs, &/or diagrams. All graphs should include a title, the independent variable labeled on the horizontal axis, and the dependent variable labeled on the vertical axis.
• All lab questions and answers should be included also with this section. ( NUMBER & UNDERLINE the questions & then write, but DON’T UNDERLINE the answers)
• SKIP ONE LINE BETWEEN EACH QUESTION!

Error Analysis

• Include any important factors that you think may have actually affected your results.

Discussion and Conclusion – 30 points

Discussion is the most important part of your report, because here, you show that you understand the experiment beyond the simple level of completing it.!!

• This is where you give a detailed account of what happened in the experiment.
• Explain all observations and results in your experiment.
• Analyze and interpret why these results were obtained.
• Be sure to tell the significance or meaning of the results.
• Restate the original hypothesis and explain whether the experiment succeeded. If the hypothesis was not correct, you should analyze why the results were not as predicted.
• Explain experimental errors that appear in the results.