Name: 
 

Genetics practice test


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

1. 
Unlike alleles in a population contribute to
a.
extinction.
c.
mutations.
b.
diversity.
d.
population control.
 

2. 
The function of a protein is determined by
a.
the number of alleles for its gene.
b.
the three-dimensional shape of the protein.
c.
the size of the protein.
d.
the rate of the protein's synthesis.
 

3. 
Gene is to chromosome as
a.
recipe is to cookbook.
c.
link is to chain.
b.
library is to encyclopedia.
d.
quarter is to dollar.
 

4. 
A eukaryotic chromosome is a
a.
long molecule of DNA, some of which is never translated.
b.
string of genes that code for proteins.
c.
string of genes that code for amino-acid sequences.
d.
long molecule of DNA, all of which is transcribed.
 

5. 
The Pace family has seven children, one son and six daughters. What is the chance that the eighth child will be a daughter?
a.
1/12
c.
1/8
b.
1/128
d.
1/2
 

6. 
What is the chance, if a couple has two children, that they will have one boy and one girl?
a.
1/2
c.
1/8
b.
1/4
d.
1/1
 

7. 
A trait that is not visible in the F1 generation but reappears unchanged in the F2 generation is
a.
recessive.
c.
monohybrid.
b.
dominant.
d.
heterozygous.
 

8. 
During gamete formation in a diploid organism,
a.
the number of chromosome pairs decreases.
b.
homologous chromosomes remain together.
c.
alleles separate from one another.
d.
independently assorted traits segregate in a 3:1 ratio.
 

9. 
What type of gametes can be produced by a pea plant with green pods and round seeds (genotype GGRr)?
a.
GG, Rr
c.
GR, Gr, gR, gr
b.
G, R, r
d.
GR, Gr
 
 
A breeding experiment using guinea pigs was conducted. The gene for rough coat (R) is dominant to the gene for smooth coat (r). A smooth-coated guinea pig was bred to a rough-coated guinea pig and had seven smooth-coated and eight rough-coated offspring.
 

10. 
Refer to the information above.  What are the genotypes of the parents?
a.
Both are homozygous recessive.
b.
Both are homozygous dominant.
c.
Both are heterozygous.
d.
One parent is homozygous recessive, and the other parent is heterozygous.
 

11. 
Refer to the information above.  What are the genotypes of the rough-coated offspring?
a.
RR
c.
Rr
b.
rr
d.
1/2 rr and 1/2 Rr
 
 
A plant that is heterozygous for tallness and heterozygous for red flowers (red and tall are dominant) self-fertilizes and has several hundred offspring. Use the key to indicate the probability that offspring could have the phenotypes listed.
 

12. 
Refer to the information above.  What is the probability that offspring will be short and white?
a.
1/16
c.
4/16
b.
3/16
d.
9/16
 

13. 
Refer to the information above.  What is the probability that offspring will be short and red?
a.
1/16
c.
4/16
b.
3/16
d.
9/16
 

14. 
Refer to the information above.  What is the probability that offspring will be tall and red?
a.
1/16
c.
4/16
b.
3/16
d.
9/16
 

15. 
Two animals with the Aa genotype had one offspring. Its genotype was aa. What is the probability that their next offspring will have the genotype aa?
a.
1/16
c.
1/4
b.
1/8
d.
1/2
 

16. 
A certain dominant gene is located on the X chromosome. A father will transmit the gene and the resulting condition to
a.
all his daughters.
c.
all his sons.
b.
only half his daughters.
d.
none of the offspring.
 

17. 
In 1988, a Florida couple charged a hospital with baby swapping, claiming that the baby they brought home was not their biological daughter. The father and the baby had type B blood, the mother type O. In terms of blood type, could the baby have belonged to this couple?
a.
Yes, this couple could have a child with either IBIB, or IBi, both type B phenotype.
b.
No, a type O mother could not have a type B child.
c.
Yes, the baby could have IBi genotype.
d.
Yes, IB is dominant to i, so a B father and an O mother would always have children with type B blood.
 

18. 
Can a person with type A blood safely receive a transfusion of type O blood?
a.
No, blood types must be identical.
b.
Yes, there are no A and B surface proteins on the type O blood cells.
c.
Yes, there are no antibodies in the type O blood.
d.
No, type A blood has anti-O antibodies.
 

19. 
The greater the chance that a break occurs between linked genes, the
a.
closer the genes are on the chromosome.
b.
greater the distance between the genes.
c.
more likely it is that the chromosome will break.
d.
less likely it is that there will be recombinations.
 

20. 
The sequence of nucleotides in a messenger RNA molecule (mRNA) is determined by the sequence of nucleotides in a
a.
transfer RNA (tRNA) molecule.
c.
polysaccharide molecule.
b.
protein molecule.
d.
DNA molecule.
 

21. 
The enzyme that initiates the first stage of transcription is
a.
ribose transcriptase.
c.
RNA polymerase.
b.
RNA transcription enzyme.
d.
RNA transcriptase.
 

22. 
Which of the following carries amino acids to the site of protein synthesis?
a.
DNA only
c.
transfer RNA only
b.
messenger RNA only
d.
messenger and transfer RNA
 

23. 
Given this sequence of DNA, AACGTACGAACGCCC, you know that correct reading of this sequence begins with the first A. If the second A is lost during transcription to mRNA, you know that
a.
the reading frame has shifted from frame 1 to frame 2.
b.
it’s only one nucleotide, so the protein product will be unaffected.
c.
the sequence of amino acids produced will be exactly as before the loss of the nucleotide.
d.
if one more nucleotide were lost, the correct reading frame would be established.
 
 


geneticspracticetes_files/i0270000.jpg

      Figure 14.04
 

24. 
Refer to Figure 14.04.  What is the best description of the mode of inheritance of the trait shown in black?
a.
simple dominant
c.
X-linked dominant
b.
simple recessive
d.
X-linked recessive
 
 


geneticspracticetes_files/i0290000.jpg

      Figure 14.05
 

25. 
Refer to Figure 14.05.  What is the best description of the mode of inheritance of the trait shown in black?
a.
simple dominant
c.
X-linked dominant
b.
simple recessive
d.
X-linked recessive
 

26. 
Refer to Figure 14.05.  Which of the following is true of square 1?
a.
It has two alleles for the trait.
c.
It has no alleles for the trait.