final pt 3

Question 1

A shotgun sequencing project yields the following sequence for a strand of DNA.

Answer 1

All of the sequences overlap with the sequence above.

Question 2

All of the genetic material transferred from a parent to an offspring is known as a:

Answer 2

genome

Question 3

Genome sequencing includes the following steps:

1. putting the sequences in the correct order
2. matching regions of overlap
3. breaking the DNA into small fragments
4. reconstructing the long sequence of nucleotides
5. sequencing the DNA

In what order are these steps carried out?

Answer 3

3-5-2-1-4

Question 4

Which of the following would be found in DNA sequences but not in mRNA sequences?

Answer 4

transcription start sites

Question 5

Which one of the following types of sequences can be found in a genome?

Answer 5

All of these choices are correct.

Question 6

Deletions that eliminate a multiple of three nucleotides can:

Answer 6

delete amino acids in a polypeptide chain.

Question 7

The number of new mutations in organisms following a round of genome replication:

Answer 7

generally increases with larger genomes.

Question 8

Insertions and deletions of single nucleotides:

Answer 8

cause frameshift mutations.

Question 9

A population of mosquitoes is exposed to the pesticide DDT for several generations. At the end of that time, most individuals in the population are resistant to DDT. The most likely reason is that

Answer 9

Some individuals in the original population had the mutations that led to resistance

Question 10

_____ mutations are important to the evolutionary process; most cancers result from _____ mutations.

Answer 10

Germ-line; somatic

Question 11

An individual is heterozygous for a gene if:

Answer 11

he or she developed from a sperm and egg that carried different alleles.

Question 12

In a population of organisms with 4 alleles, how many homozygous genotypes are possible? How many heterozygous genotypes are possible?

Answer 12

4; 6

Question 13

The term “genotype-by-environment interaction” applies to a situation in which:

Answer 13

the effects of genotype and environment on a phenotype are interdependent.

Question 14

Which of the following types of mutations are thought to be the least common?

Answer 14

beneficial mutations

Question 15

“Any difference among individuals that is sufficiently common such that it would almost certainly be present in a group of 50 individuals chosen at random” is the definition of a(n):

Answer 15

polymorphism

Question 16

Mendel studies seven different traits in the garden pea. What genetic term is used to describe an observable trait, such as those studied by Mendel?

Answer 16

phenotype

Question 17

A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?

Answer 17

HT

Question 18

Different ratios occur in crosses with single gene pairs or two gene pairs. What types of ratios are likely to occur in crosses dealing with a single gene pair?

Answer 18

3:1, 1:1, 1:2:1

Question 19

Mendel’s observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division?

Answer 19

anaphase I of meiosis

Question 20

Feather color in birds of paradise is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. A blue budgie is crossed with a white budgie. Which of the following results is NOT possible?

Answer 20

green and yellow offspring

Question 21

Given equal probabilities of the birth of a boy or girl, if a group of four siblings consists of all girls, what is the probability that the next birth is a boy?

Answer 21

1/2

Question 22

Genes located along the X chromosome:

Answer 22

are called X-linked genes

Question 23

Which one of the following statements regarding the human Y chromosome is true?

Answer 23

The Y chromosome contains approximately 50 genes

Question 24

The pedigree shown here pertains to a trait due to a rare, X-linked recessive mutation.

Individual 1 has an affected brother, but the genotypes and phenotypes of individuals 1–4 are unknown. What is the probability that individual 1 is heterozygous? What is the probability that individual 3 is heterozygous? What is the probability that individual 4 is affected?

Answer 24

1/2; 1/4; 1/4

Question 25

Red-green color blindness is due to a mutant gene in the X chromosome. An XX female with normal color vision and an XY male with normal color vision have a child with karyotype XXY who is color blind. The likely explanation is:

Answer 25

the mother was heterozygous for the color-blind mutation

Question 26

A key difference between single-gene traits such as those Mendel studied and complex traits such as human height is that:

Answer 26

single-gene traits are generally uninfluenced by the environment, whereas complex traits have a significant environmental component.

Question 27

If all variation among individuals in a population is due to differing environments, heritability is ____, and the slope of the line used to measure it is ____.

Answer 27

0; 0

Question 28

Which of the following would be good examples of genotype-by-environment interactions?

Answer 28

a strain of corn whose yield varies with the amount of nutrients in the soil

Question 29

Which of the following is the best example of how we can separate the effects of genes and the environment on the expression of a complex trait?

Answer 29

In a group of individuals of the same sex, about 80% of the variation in height among individuals is due to genetic differences and 20% is due to environmental differences.

Question 30

If all variation among individuals in a population is due to differing genotypes, heritability is ____, and the slope of the line used to measure it is ____.

Answer 30

100%; 1

Question 31

Cancer is usually due to:

Answer 31

a series of mutations that occur in a single lineage of somatic cells.

Question 32

You are studying two traits in fruit flies:
eye color where there are two colors, brown and red, and
wing shape where there are straight and curled phenotypes.
You mate two flies that are heterozygous for the genes that control both of these traits and get the following phenotypes in the following ratio:

9 red and straight; 3 red and curled; 3 brown and straight; 1 brown and curled

Considering the traits in the previous question, which alleles separated at which stages of meiosis?

Answer 32

red segregated from brown in meiosis I, and straight segregated from curled in meiosis I

Question 33

In humans, mitochondria (and their genomes) show:

Answer 33

strict maternal inheritance