Deck 16: Genetics

Question 1

RNA and DNA differ in all of the following except:

A)RNA is single-stranded rather than double-stranded.
B)RNA uses a different sugar from DNA.
C)RNA uses a completely different set of nitrogenous bases compared to DNA.
D)RNA uses the nitrogenous base uracil (U)in place of thymine (T).

Answer 1

C

Question 2

Which of the following would produce a frameshift mutation?

A)the insertion of a single nucleotide in a gene
B)the deletion of a single nucleotide in a gene
C)the replacement of one nucleotide with another in a gene
D)both A and B

Answer 2

D

Question 3

Codons that signal that there are no more amino acids in a protein are

A)nonsense codons.
B)stop codons.
C)anticodons.
D)transfer codons.

Answer 3

B

Question 4

Which statement about genetic mutations is false?

A)Genetic mutations are always harmful.
B)Genetic mutations can be caused by ultraviolet light.
C)Genetic mutations in eggs or sperm may be particularly significant because they can be passed to offspring, where they will affect every cell in the offspring's body.
D)Genetic mutations are the ultimate source of all genetic variation, and so they provide the raw materials for evolution and natural selection.

Question 5

One strand of DNA has the sequence CAGTC. The opposite strand has the sequence

A)GTCAG.
B)ATCGA.
C)TCAGT.
D)none of the above

Question 6

Transcription occurs in the ________ of a cell, and translation occurs in the ________ of a cell.

A)nucleus; cytoplasm
B)nucleus; nucleus
C)cytoplasm; nucleus
D)cytoplasm; cytoplasm

Question 7

The genes of an organism make up its ________, and the traits of an organism make up its ________.

A)phenotype; chromosomes
B)enzymes; genotype
C)genotype; phenotype
D)phenotype; genotype

Question 8

An RNA transcript constructed from the DNA sequence ATTGC would have the nucleotide sequence

A)ATTGC.
B)AUUGC.
C)UAACG.
D)TAACG.

Question 9

Which of the following statements is false?

A)Human females and males have the same number of chromosomes.
B)Human females have two X chromosomes.
C)Human males have a Y chromosome.
D)Human males have no X chromosomes.

Question 10

If an organism's diploid cells have 40 chromosomes, then its haploid cells have

A)80 chromosomes.
B)40 chromosomes.
C)20 chromosomes.
D)none of the above

Question 11

When DNA is replicated in eukaryotes,

A)the new molecule of DNA consists of two newly synthesized strands.
B)a molecule of messenger RNA (mRNA)is constructed using DNA as a template.
C)the new molecule of DNA includes the bases A, C, T, and U.
D)each new molecule of DNA consists of one old strand and one new strand.

Question 12

A mutation in which one nucleotide is substituted for another is called a

A)nonsense mutation.
B)frameshift mutation.
C)point mutation.
D)none of the above

Question 13

If DNA is described as resembling a ladder in structure, the "sides" of the ladder consist of ________ and the "rungs" of the ladder consist of ________.

A)sugar; phosphate
B)sugar and phosphate; nitrogenous bases
C)sugar and phospholipids; nitrogenous bases
D)sugar and nitrogenous bases; phosphate

Question 14

The genetic code describes

A)how different codons correspond to amino acids.
B)the A-C-T-G sequence of nucleotides in different organisms.
C)how codons bind to anticodons.
D)none of the above

Question 15

All of the following are found in chromosomes except

A)DNA.
B)RNA.
C)histones.
D)proteins.

Question 16

The sections of an RNA transcript that are removed before translation are

A)introns.
B)exons.
C)caps.
D)tails.

Question 17

The molecule that is made during transcription is

A)messenger RNA.
B)transfer RNA.
C)ribosomal RNA.
D)DNA.

Question 18

Which of the following is least likely to disrupt a protein's function?

A)a frameshift mutation that occurs near the beginning of the gene
B)a nonsense mutation in the middle of a gene
C)a nonsense mutation near the end of a gene
D)All of the above are equally likely to disrupt protein function.

Question 19

Which of the following statements regarding transcription and translation is true?

A)mRNA includes the bases A, C, G, and T.
B)An RNA transcript may contain sections that are removed before translation.
C)A codon consists of a sequence of two nucleotides.
D)A tRNA molecule includes a codon sequence and carries a single amino acid.

Question 20

The proper sequence of events in building a protein from a gene is

A)replication, transcription, translation.
B)transcription, translation.
C)translation, transcription, replication.
D)translation, transcription.

Question 21

Human height and skin color are examples of

A)codominance.
B)pleiotropy.
C)incomplete dominance.
D)polygenic traits.

Question 22

The fact that a red-flowered snapdragon bred to a white-flowered snapdragon produces pink-flowered offspring is an example of

A)codominance.
B)pleiotropy.
C)incomplete dominance.
D)blending inheritance.

Question 23

Transgenic plants

A)can be used to make human medicines.
B)include some varieties that are resistant to pests.
C)may be more resistant to drought or salty soils.
D)all of the above

Question 24

When Mendel bred green-pea plants with yellow-pea plants, all the offspring had yellow peas. This means that the trait for yellow peas is

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

Question 25

Genetically modified crops

A)have been shown, in multiple studies, to be dangerous to eat.
B)cannot transfer their genes to other species.
C)have contaminated traditional seed supplies with their genes.
D)are advantageous for farmers because the seeds are inexpensive.

Question 26

A gene that normally prevents cancer by inhibiting cell division is a

A)proto-oncogene.
B)oncogene.
C)tumor suppressor gene.
D)metastasis gene.

Question 27

One environmental risk factor for skin cancer is

A)diet.
B)infection by certain viruses.
C)exposure to ultraviolet light.
D)exposure to X-rays.

Question 28

All of the following cell types are particularly prone to damage from mutation-causing agents except

A)brain cells.
B)bone marrow cells.
C)cells in a developing fetus.
D)cancer cells.

Question 29

What is the role of transfer RNA in translation?

Question 30

What is a gene? Why are so many of an organism's traits determined by its genes?

Question 31

Describe point mutations, nonsense mutations, and frameshift mutations. Discuss the likely effect of each type of mutation on a protein being built.

Question 32

The AB blood type in humans is an example of

A)codominance.
B)pleiotropy.
C)incomplete dominance.
D)a polygenic trait.

Question 33

How is DNA copied? How does the mechanism for copying DNA explain the fact that every new DNA molecule includes one old strand and one newly made strand?

Question 34

All of the following statements regarding meiosis are true except:

A)It produces haploid cells.
B)It is a form of cell division in which one parent cell divides ultimately into four daughter cells.
C)It occurs in all cells in the human body.
D)It is important for allowing a chromosome to exchange corresponding parts with its homologous chromosome.

Question 35

How does crossing over during meiosis produce genetic diversity among the sex cells of a single organism?

Question 36

Cancer

A)is usually caused by a single mutation in a key gene.
B)is more likely to develop in older people or people who have been exposed to mutagens (mutation-causing agents).
C)usually involves a mutation in the BRCA genes.
D)is primarily an inherited, and not an environmental, disease.

Question 37

If a widow's peak hairline is dominant and a straight hairline is recessive, then a person with a

A)straight hairline must be a heterozygote.
B)widow's peak hairline must be a heterozygote.
C)straight hairline must be a homozygote.
D)widow's peak hairline must be a homozygote.

Question 38

A SNP is

A)a mutation that affects eggs or sperm.
B)a location in the human genome where the nucleotide sequence differs among individuals.
C)almost always a recessive allele.
D)a repeat sequence in the human genome.

Question 39

If a widow's peak hairline is dominant and a straight hairline is recessive, then

A)all the children of two widow-peaked parents will have widow's peaks.
B)some of the children of two widow-peaked parents will have straight hairlines.
C)all the children of two straight-hairline parents will have straight hairlines.
D)some of the children of two straight-hairline parents could have widow's peaks.

Question 40

All of the following statements about sex-linked traits are true except:

A)They include human colorblindness.
B)They are determined by genes found on the sex chromosomes.
C)They usually affect more females than males.
D)They include the blood disease hemophilia.