Question 1

31)	Imagine that a newly discovered species of fish normally has three eyes ( E), but the rare mutation
(e)	causes ?diopthalmic? fish with two eyes to be born. In addition, eye color in these fish is inherited similarly to humans, with black eyes (B) being dominant to blue (b). Assuming these two genes are carried on separate chromosomes, what must the genotypes of two black -eyed,
three-eyed parents be if they have a blue-eyed, diopthalmic son?

Accepted Answer

A)  eeBB and EEbb 
B)  Both EeBb 
C)  Both eebb 
D)  EEBB and eebb

Question 2

All of the following combinations are possible in the gametes of an organism that is AaBb EXCEPT

Accepted Answer

A)  aa. 
B)  AB. 
C)  ab. 
D)  aB. 
E)  Ab.

Question 3

Hemophilia is a sex-linked recessive gene that causes a blood disorder. What are the chances that the daughter of a normal man and a heterozygous woman will have hemophilia?

Accepted Answer

A)  75% 
B)  100% 
C)  50% 
D)  0% 
E)  25%

Question 4

What type of allele produces its effects in only homozygous individuals?

Accepted Answer

A)  Haploid 
B)  Recessive 
C)  Diploid 
D)  Dominant

Question 5

The blood types of humans are an example of__________ .

Accepted Answer

The answer of The blood types of humans are an...

Question 6

Human females who receive sex-linked genes always express them.

Accepted Answer

A) True 
 B)False

Question 7

Which disorder is characterized by an abnormal number of autosomes?

Accepted Answer

A)  Turner syndrome 
B)  Klinefelter syndrome 
C)  Trisomy X 
D)  XYY syndrome 
E)  Down syndrome

Question 8

-Hemophilia is a genetic disease that has plagued the royal houses of Europe since the time of Queen Victoria, who was a carrier. Her granddaughter, Alexandra, married Nicholas II, the last czar of imperial Russia. Alexandra was a carrier for hemophilia, but Nicholas was normal. Their son, Alexis, was afflicted with the disease. Based on this scenario, it is most likely that

Accepted Answer

A)  all four sisters were carriers of the hemophilia gene. 
B)  at least one of the sisters had hemophilia. 
C)  each of the sisters had a 50% chance of being a carrier of the gene. 
D)  Alexis inherited the hemophilia gene from Nicholas II. 
E)  none of the four sisters carried the hemophilia gene.

Question 9

Imagine that you self-pollinate heterozygous purple-flowered, long-pollened pea plants and get mostly purple-flowered, long-pollened plants and white-flowered, short-pollened plants, with a few purple-flowered, short-pollened or white-flowered, long-pollened plants. What is the most likely explanation?

Accepted Answer

A)  The genes for flower color and pollen length are linked. 
B)  The gene for flower color is on a sex chromosome. 
C)  Long pollen is often lethal, so few plants with long pollen survive to adulthood. 
D)  The purple allele influences pollen to become shorter. 
E)  This is a normal random variation from the expected ratio for independent assortment.

Question 10

Round pea shape (R) is dominant over wrinkled pea shape (r). If a round pea has a wrinkled parent, the round pea is

Accepted Answer

A)  RR. 
B)  rr. 
C)  recessive. 
D)  Rr. 
E)  haploid.

Question 11

In humans, the sex of the offspring is determined by the

Accepted Answer

A)  cytoplasm carried by the egg cell. 
B)  autosomes carried by the sperm cell. 
C)  autosomes carried by the egg cell. 
D)  sex chromosome carried by the sperm cell. 
E)  sex chromosome carried by the egg cell.

Question 12

Sickle-cell anemia is caused by a

Accepted Answer

A)  recessive autosomal gene. 
B)  recessive sex-linked gene. 
C)  dominant autosomal gene. 
D)  combined interaction of several genes. 
E)  simple dominant gene.

Question 13

When the expression of a trait is influenced by the action of many genes, the pattern of inheritance is called

Accepted Answer

A)  incomplete dominance. 
B)  multiple alleles. 
C)  polygenic inheritance. 
D)  discontinuous variation. 
E)  complete dominance.

Question 14

What is the ratio of phenotypes in the offspring produced by the cross Aa × Aa? Assume complete dominance for the trait.

Accepted Answer

A)  100% dominance 
B)  50% dominant:50% recessive 
C)  75% dominant:25% recessive 
D)  25% dominant:75% recessive 
E)  100% recessive

Question 15

When the two gametes that fuse to form a zygote contain different alleles of a given gene, the offspring is

Accepted Answer

A)  heterozygous. 
B)  haploid. 
C)  homozygous. 
D)  abnormal. 
E)  a new species.

Question 16

If you cross pea plants that are both heterozygous for purple flowers and yellow seeds ( PpYy), and you examine 800 offspring for flower and seed color, about how many do you expect to have white flowers and green seeds?

Accepted Answer

A)  450 
B)  All of them (800) 
C)  50 
D)  150 
E)  None of them

Question 17

What would be TRUE if linkage of two genes was complete?

Accepted Answer

A)  All possible combinations of alleles in the offspring would be produced. 
B)  The genes would assort independently. 
C)  All possible combinations of alleles in the gametes would be produced. 
D)  Crossing over between the two genes would rarely occur.

Question 18

Which of the following is TRUE of genes that are physically located close to each other on the same chromosome?

Accepted Answer

A)  They are not linked. 
B)  They tend to not be inherited together. 
C)  They are linked and tend to be inherited together. 
D)  They will be expressed differently in males than in females.

Exam 11: Patterns of Inheritance