Question 1

Muscular dystrophy is a group of inherited disorders that lead to increasing muscle cell loss and thus muscle weakness over time. There are many different types of muscular dystrophy. Symptoms can vary, although all involve muscle weakness. Duchenne muscular dystrophy (DMD) is a recessive X-linked form that leads to muscle degeneration and death usually by age 25. Symptoms begin before age 5 and include low endurance and difficulties standing. As the condition progresses, muscle tissue is replaced with adipose and other types of connective tissue. Abnormal bone development and some neurobehavioral and learning disabilities may also occur. DMD occurs as a result of a mutation in a single gene on the X chromosome. This gene codes for a particular protein, dystrophin, which plays a major role in the structure of muscle cells. The protein formed by the mutated gene is nonfunctional, and the absence of a functional protein eventually leads to cell death. A young boy has DMD. What do you know about his parents?

Accepted Answer

A)  Both of his parents are carriers of DMD. 
B)  At least one of his parents is a carrier of DMD. 
C)  His mother is a carrier of DMD. 
D)  His father is a carrier of DMD.

Question 2

Has this cell undergone meiosis?

Accepted Answer

A)  yes, because there are no duplicated chromosomes 
B)  no, because homologous chromosomes are present 
C)  yes, because homologous chromosomes are not present 
D)  no, because the diploid number is 2

Question 3

If this is a cell in your body where the letter "P" represents some trait,

Accepted Answer

A)  P came from one parent and p from another parent. 
B)  both alleles came from one parent. 
C)  P came from your father and p from your mother. 
D)  four different alleles are represented.

Question 4

If a particular trait has three phenotypes and one phenotype represents an intermediate, this trait displays __________.

Accepted Answer

A)  incomplete dominance 
B)  codominance 
C)  recessive alleles 
D)  dominant alleles

Question 5

The gene that codes for the number of fingers on the human hand has two alleles-five fingers and six fingers. The letters F and f are used to represent this trait. Having five fingers is the recessive trait. A woman has six fingers, but one of her parents has five fingers. She marries a man who has five fingers. What is the probability that they will have a child who has five fingers?

Accepted Answer

A)  0 percent 
B)  25 percent 
C)  50 percent 
D)  100 percent

Question 6

The gene that codes for the number of fingers on the human hand has two alleles-five fingers and six fingers. The letters F and f are used to represent this trait. Having five fingers is the recessive trait. A woman has six fingers, but one of her parents has five fingers. What is the genotype of the woman?

Accepted Answer

A)  Ff 
B)  ff 
C)  FF 
D)  either FF or ff

Question 7

The gene that codes for the number of fingers on the human hand has two alleles-five fingers and six fingers. The letters F and f are used to represent this trait. Having five fingers is the recessive trait. If a person has five fingers, his genotype is _____.

Accepted Answer

A)  ff 
B)  Ff 
C)  FF 
D)  Ff or ff

Question 8

The gene that codes for the number of fingers on the human hand has two alleles-five fingers and six fingers. The letters F and f are used to represent this trait. Having five fingers is the recessive trait. The majority of the human population is __________ for this trait.

Accepted Answer

A)  homozygous recessive 
B)  homozygous dominant 
C)  heterozygous 
D)  codominant

Question 9

Genes are expressed as functional and structural __________.

Accepted Answer

A)  nucleic acids 
B)  forms of energy 
C)  proteins 
D)  carbohydrates

Question 10

Reduced health and vigor as a result of breeding related individuals is called __________.

Accepted Answer

A)  inbreeding depression 
B)  breeding depression 
C)  inbreeding repression 
D)  breeding repression

Question 11

Some chickens have a dominant frizzle gene that leads to the development of feathers that curl outward rather than lying flat against their bodies as in standard chickens. Aside from these "frizzled feathers," chickens with this dominant allele also tend to have higher metabolic rates and produce fewer eggs than chickens that carry the recessive version of this gene. Thus, this gene exhibits __________.

Accepted Answer

A)  pleiotropy 
B)  polygenic inheritance 
C)  incomplete dominance 
D)  codominance

Question 12

What was the major contribution of Gregor Mendel?

Accepted Answer

A)  He coined the term genes. 
B)  He provided evidence for how traits are inherited. 
C)  He described how genes code for particular proteins. 
D)  He explained the central role of proteins in the expression of traits.

Question 13

The gene that codes for the number of fingers on the human hand has two alleles-five fingers and six fingers. The letters F and f are used to represent this trait. Having five fingers is the recessive trait. If a person has six fingers, her genotype is _____.

Accepted Answer

A)  ff 
B)  Ff 
C)  FF 
D)  Ff or FF

Question 14

The diploid number for this cell is __________.

Accepted Answer

A)  2 
B)  4 
C)  8 
D)  2n

Question 15

A person with which of the following blood types is a universal donor who can donate blood to anyone with any other blood type?

Accepted Answer

A)  O 
B)  AB 
C)  A 
D)  B

Question 16

Muscular dystrophy is a group of inherited disorders that lead to increasing muscle cell loss and thus muscle weakness over time. There are many different types of muscular dystrophy. Symptoms can vary, although all involve muscle weakness. Duchenne muscular dystrophy (DMD) is a recessive X-linked form that leads to muscle degeneration and death usually by age 25. Symptoms begin before age 5 and include low endurance and difficulties standing. As the condition progresses, muscle tissue is replaced with adipose and other types of connective tissue. Abnormal bone development and some neurobehavioral and learning disabilities may also occur. DMD occurs as a result of a mutation in a single gene on the X chromosome. This gene codes for a particular protein, dystrophin, which plays a major role in the structure of muscle cells. The protein formed by the mutated gene is nonfunctional, and the absence of a functional protein eventually leads to cell death. The protein dystrophin is produced ____________________.

Accepted Answer

A)  at the ribosomes in the cytoplasm 
B)  in the nucleus of the cell 
C)  in the Golgi complex of the cell 
D)  in lysosomes

Question 17

A Norfolk chicken has feathers that have an overall gray appearance, but if you look at an individual feather, it is either black or white. Feather color in these birds is expressed as __________.

Accepted Answer

A)  codominance 
B)  incomplete dominance 
C)  sex-linked 
D)  pleiotropy

Question 18

Which of the following is most closely related to chimpanzees and humans?

Accepted Answer

A)  gorillas 
B)  orangutans 
C)  all apes 
D)  gibbons

Question 19

Muscular dystrophy is a group of inherited disorders that lead to increasing muscle cell loss and thus muscle weakness over time. There are many different types of muscular dystrophy. Symptoms can vary, although all involve muscle weakness. Duchenne muscular dystrophy (DMD) is a recessive X-linked form that leads to muscle degeneration and death usually by age 25. Symptoms begin before age 5 and include low endurance and difficulties standing. As the condition progresses, muscle tissue is replaced with adipose and other types of connective tissue. Abnormal bone development and some neurobehavioral and learning disabilities may also occur. DMD occurs as a result of a mutation in a single gene on the X chromosome. This gene codes for a particular protein, dystrophin, which plays a major role in the structure of muscle cells. The protein formed by the mutated gene is nonfunctional, and the absence of a functional protein eventually leads to cell death. In producing the protein dystrophin, DNA is __________ to RNA and then __________ to a protein in the cytoplasm of the cell.

Accepted Answer

A)  transcribed; translated 
B)  translated; transcribed

Question 20

Green seed color is dominant over yellow seed color. If a plant produces gametes with only yellow seed color, which of the following must be true?

Accepted Answer

A)  Both parents were homozygous recessive for this trait. 
B)  Both parents carried the recessive trait. 
C)  One parent was homozygous recessive, and the other was homozygous dominant. 
D)  Both parents were homozygous dominant for this trait.

Exam 18: Patterns of Inheritance