Name: 
 

Genetics


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

1. 
The chemical factors that determine traits are called
a.
alleles.
b.
traits.
c.
genes.
d.
characters.
 

2. 
The principle of dominance states that
a.
all alleles are dominant.
b.
all alleles are recessive.
c.
some alleles are dominant and others are recessive.
d.
alleles are neither dominant nor recessive.
 

3. 
Organisms that have two identical alleles for a particular trait are said to be
a.
hybrid.
b.
homozygous.
c.
heterozygous.
d.
dominant.
 

4. 
The number of chromosomes in a gamete is represented by the symbol
a.
Z.
b.
X.
c.
N.
d.
Y.
 

5. 
If an organism’s diploid number is 12, its haploid number is
a.
12.
b.
6.
c.
24.
d.
3.
 

6. 
Gametes are produced by the process of
a.
mitosis.
b.
meiosis.
c.
crossing-over.
d.
replication.
 
 
inherittest_files/i0080000.jpg

Figure 11-3
 

7. 
What is shown in Figure 11-3?
a.
independent assortment
b.
anaphase I of meiosis
c.
crossing-over
d.
replication
 

8. 
Chromosomes form tetrads during
a.
prophase of meiosis I.
b.
metaphase of meiosis I.
c.
interphase.
d.
anaphase of meiosis II.
 

9. 
Unlike mitosis, meiosis results in the formation of
a.
two genetically identical cells.
b.
four genetically different cells.
c.
four genetically identical cells.
d.
two genetically different cells.
 

10. 
Linked genes
a.
are never separated.
b.
assort independently.
c.
are on the same chromosome.
d.
are always recessive.
 

11. 
How many chromosomes are shown in a normal human karyotype?
a.
2
b.
23
c.
44
d.
46
 

12. 
Which of the following can be observed in a karyotype?
a.
a change in a DNA base
b.
an extra chromosome
c.
genes
d.
alleles
 

13. 
In humans, a male has
a.
one X chromosome only.
b.
two X chromosomes.
c.
one X chromosome and one Y chromosome.
d.
two Y chromosomes.
 

14. 
Colorblindness is more common in males than in females because
a.
fathers pass the allele for colorblindness to their sons only.
b.
the allele for colorblindness is located on the Y chromosome.
c.
the allele for colorblindness is recessive and located on the X chromosome.
d.
males who are colorblind have two copies of the allele for colorblindness.
 

15. 
The failure of chromosomes to separate during meiosis is called
a.
nondisjunction.
b.
X-chromosome inactivation.
c.
Turner’s syndrome.
d.
Down syndrome.
 

16. 
Because the X chromosome contains genes that are vital for normal development, no baby has been born
a.
with one X chromosome.
b.
with three X chromosomes.
c.
without an X chromosome.
d.
with four X chromosomes.
 



 
Check Your Work     Reset Help