genetics practice testbi

Chapter 9 Test, Form A

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

1. 

The “father” of genetics was
a.
T. A. Knight.
c.
Gregor Mendel.
b.
Hans Krebs.
d.
None of the above
 

2. 

Mendel obtained his P generation by allowing the plants to
a.
self-pollinate.
c.
assort independently.
b.
cross-pollinate.
d.
segregate.
 

3. 

What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype?
a.
0.25
c.
0.66
b.
0.5
d.
1.0
 

4. 

True-breeding pea plants always
a.
are pollinated by hand.
b.
produce offspring with either form of a trait.
c.
produce offspring with only one form of a trait.
d.
are heterozygous.
 

5. 

The first filial (F1) generation is the result of
a.
cross-pollination among parents and the next generation.
b.
crosses between individuals of the parental generation.
c.
crosses between the offspring of a parental cross.
d.
self-fertilization between parental stock.
 

6. 

Which of the following is the designation for Mendel’s original pure strains of plants?
a.
P
c.
F1
b.
P1
d.
F2
 

7. 

A genetic trait that appears in every generation of offspring is called
a.
dominant.
c.
recessive.
b.
phenotypic.
d.
superior.
 

8. 

To describe how traits can disappear and reappear in a certain pattern from generation to generation, Mendel proposed
a.
the law of independent assortment.
b.
the law of segregation.
c.
the law of genotypes.
d.
that the F2 generation will only produce purple flowers.
 

9. 

When Mendel crossed pea plants with two contrasting traits, such as flower color and plant height,
a.
these experiments led to his law of segregation.
b.
he found that the inheritance of one trait did not influence the inheritance of the other trait.
c.
he found that the inheritance of one trait influenced the inheritance of the other trait.
d.
these experiments were considered failures because the importance of his work was not recognized.
 

10. 

If an individual has two recessive alleles for the same trait, the individual is said to be
a.
homozygous for the trait.
c.
heterozygous for the trait.
b.
haploid for the trait.
d.
mutated.
 

11. 

An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring that are
a.
all the same genotype.
c.
of three different phenotypes.
b.
of two different phenotypes.
d.
all the same phenotype.
 
 
In humans, having freckles (F) is dominant to not having freckles (f). The inheritance of these traits can be studied using a Punnett square similar to the one shown below.
      evhm2gen-b_files/i0100000.jpg
 

12. 

Refer to the illustration above. The genotype represented in box “1” in the Punnett square would
a.
be homozygous for freckles.
b.
have an extra freckles chromosome.
c.
be heterozygous for freckles.
d.
have freckles chromosomes.
 

13. 

Refer to the illustration above. The genotype in box “3” of the Punnett square is
a.
FF.
c.
ff.
b.
Ff.
d.
None of the above
 

14. 

How many different phenotypes can be produced by a pair of codominant alleles?
a.
1
c.
3
b.
2
d.
4
 
 
evhm2gen-b_files/i0130000.jpg
 

15. 

Refer to the illustration above. The phenotype represented by the cell labeled “1” is
a.
green, inflated.
c.
yellow, inflated.
b.
green, constricted.
d.
yellow, constricted.
 

16. 

2,000 yellow seeds : 8,000 total seeds ::
a.
1 : 6
c.
1 : 3
b.
1 : 8
d.
1 : 4
 
 
In rabbits, black fur (B) is dominant to brown fur (b). Consider the following cross between two rabbits.
      evhm2gen-b_files/i0160000.jpg
 

17. 

Refer to the illustration above. Both of the parents in the cross are
a.
black.
c.
homozygous dominant.
b.
brown.
d.
homozygous recessive.
 

18. 

Refer to the illustration above. The phenotype of the offspring indicated by box “3” would be
a.
brown.
c.
a mixture of brown and black.
b.
black.
d.
The phenotype cannot be determined.
 

19. 

What is the expected phenotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross?
a.
1:3:1
c.
2:1
b.
1:2:1
d.
1:0
 
 
      evhm2gen-b_files/i0240000.jpg
 

20. 

Refer to the illustration above. The phenotype represented by the cell labeled “1” is
a.
round, yellow.
c.
wrinkled, yellow.
b.
round, green.
d.
wrinkled, green.
 

21. 

An organism that has inherited two of the same alleles of a gene from its parents is called
a.
hereditary.
c.
homozygous.
b.
heterozygous.
d.
a mutation.
 

22. 

In pea plants, yellow seeds are dominant over green seeds. What would be the expected genotype ratio in a cross between a plant with green seeds and a plant that is heterozygous for seed color?
a.
1:3
c.
4:1
b.
1:2:1
d.
1:1
 

23. 

codominance : both traits are displayed ::
a.
probability : crosses
b.
heterozygous : alleles are the same
c.
homozygous : alleles are the same
d.
Punnett square : chromosomes combine
 

24. 

The difference between a monohybrid cross and a dihybrid cross is that
a.
monohybrid crosses involve traits for which only one allele exists, while dihybrid traits involve two alleles.
b.
monohybrid crosses involve self-pollination, while dihybrid crosses involve cross-pollination.
c.
monohybrid crosses involve one gene; dihybrid crosses involve two genes.
d.
dihybrid crosses require two Punnett squares; monohybrid crosses need only one.
 

25. 

What fraction of the offspring resulting from a heterozygous ´ heterozygous dihybrid cross are heterozygous for both traits?
a.
9/16
c.
3/16
b.
1/4
d.
1/16
 


 
Submit          Reset