Question 1

Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that it can be tested for abnormalities.

Accepted Answer

A)  imaging; karyotyping 
B)  sexing; imaging 
C)  karyotyping; biochemical testing 
D)  direct observation; biochemical testing

Question 2

All the offspring of a cross between a black-eyed Mendelian and an orange-eyed Mendelian have black eyes. What is the expected phenotypic ratio of a cross between two orange-eyed Mendelians?

Accepted Answer

A)  3 black-eyed:1 orange-eyed 
B)  0 black-eyed:1 orange-eyed 
C)  1 black-eyed:3 orange-eyed 
D)  1 black-eyed:0 orange-eyed

Question 3

The alleles of a gene are found at ________ chromosomes.

Accepted Answer

A)  the same locus on nonhomologous 
B)  different loci on homologous 
C)  different loci on nonhomologous 
D)  the same locus on homologous

Question 4

Which of the following statements regarding sickle-cell disease is false?

Accepted Answer

A)  Persons who are heterozygous for sickle-cell disease are also resistant to malaria. 
B)  Sickle-cell disease causes white blood cells to be sickle-shaped. 
C)  All of the symptoms of sickle-cell disease result from the actions of just one allele. 
D)  About 1 in 10 African Americans is a carrier of sickle-cell disease.

Question 5

What is meant by the statement that "male bees are fatherless"?

Accepted Answer

A)  Male bees don't play a role in the rearing of bee young. 
B)  Male bees are produced by budding. 
C)  Male bees develop from unfertilized eggs. 
D)  The queen bee's mate dies before the male eggs hatch.

Question 6

Which of the following statements best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?

Accepted Answer

A)  Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles. 
B)  Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause the death of the embryo. 
C)  Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce. 
D)  The presence of a lethal dominant allele causes sterility.

Question 7

Research since Mendel's time has established that the law of segregation of genes during gamete formation

Accepted Answer

A)  applies to all forms of life. 
B)  applies to all sexually reproducing organisms. 
C)  applies to all asexually reproducing organisms.

Question 8

Mendel's law of independent assortment states that

Accepted Answer

A)  chromosomes sort independently of each other during mitosis and meiosis. 
B)  independent sorting of genes produces polyploid plants under some circumstances. 
C)  each pair of alleles (chromosomes) segregates independently of the other pairs of alleles during gamete formation. 
D)  genes are sorted concurrently during gamete formation.

Question 9

Which plants in this figure must all be heterozygous?

Accepted Answer

A)  purple-flowered plants in the P generation 
B)  white-flowered plants in the P generation 
C)  purple-flowered plants in the F1 generation 
D)  purple-flowered plants in the F2 generation

Question 10

Sickle-cell disease is an example of

Accepted Answer

A)  pleiotropy. 
B)  polygenic inheritance. 
C)  a trait with more than two alleles.

Question 11

Imagine that we mate two black Labrador dogs with normal vision and find that three of the puppies are like the parents, but one puppy is chocolate with normal vision and another is black with PRA (progressive retinal atrophy, a serious disease of vision). We can conclude that

Accepted Answer

A)  both of the parents are homozygous for both traits. 
B)  the same alleles that control coat color can also cause PRA. 
C)  the alleles for color and vision segregate independently during gamete formation. 
D)  the alleles for color and vision segregate dependently during gamete formation.

Question 12

A colorblind woman marries a man who is not colorblind. All of their sons, but none of their daughters, are colorblind. Which of the following statements correctly explains these results?

Accepted Answer

A)  The gene for color vision is incompletely dominant to the gene for sex determination. 
B)  The gene for color vision is codominant with the gene for sex determination. 
C)  The gene for color vision is found on the X chromosome. 
D)  The gene for color vision is found on the Y chromosome.

Question 13

Which of the following kinds of data could be used to map the relative position of three genes on a chromosome?

Accepted Answer

A)  the frequencies with which the genes exhibit incomplete dominance over each other 
B)  the frequencies of mutations in the genes 
C)  the frequencies with which the genes are inherited from the mother and from the father 
D)  the frequencies with which the corresponding traits occur together in offspring

Question 14

Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes?

Accepted Answer

A)  DD and dd 
B)  dd and dd 
C)  Dd and Dd 
D)  Dd and DD

Question 15

In giraffes, long necks (N), long legs (L), dark spots (D), and the ability to digest maize (M) are all dominant traits. What possible genotype could a long-necked, short-legged, light-spotted, maize-digesting giraffe have?

Accepted Answer

A)  NnllddMM 
B)  NNLLDdMm 
C)  NNllddmm 
D)  nnLLddMM

Question 16

What is the normal complement of sex chromosomes in a human male?

Accepted Answer

A)  two Y chromosomes and zero X chromosomes 
B)  two X chromosomes and one Y chromosome 
C)  one X chromosome and one Y chromosome 
D)  one Y chromosome and zero X chromosomes

Exam 9: Patterns of Inheritance

Amniocentesis and chorionic villus sampling allow for and of the fetus so that it can be tested for abnormalities.