Chapter 6, 5 Practice Questions

During DNA replication, __________.

A. a new daughter DNA molecule contains two newly synthesized strands that are identical copies of the original DNA molecule
B. each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand
C. only one of the strands of the parent DNA molecule serves as a template for DNA replication
D. the original DNA molecule is destroyed

B. each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand

In what way might you expect transcription and translation to be different in prokaryotic cells compared to eukaryotic cells?

A. Transcription follows different base pairing rules in prokaryotic cells.
B. In prokaryotes, transcription and translation can take place at the same place and same time.
C. In prokaryotic cells, translation can occur before transcription.
D. Transcription is not necessary in prokaryotic cells. Genetic information can be directly translated from DNA.

B. In prokaryotes, transcription and translation can take place at the same place and same time.

During transcription of a specific gene, only one DNA strand serves as a template for the formation of RNA.

A. True
B. False

A. True

Alternative splicing allows the production of several different proteins from the same gene in both prokaryotes and eukaryotes.

A. True
B. False

B. False

Translation begins when a __________ molecule binds to a ________.

A. mRNA; complete ribosome
B. mRNA; small ribosomal subunit
C. tRNA; small ribosomal subunit
D. tRNA; large ribosomal subunit

B. mRNA; small ribosomal subunit

Every cell in your body can express every one of your genes.

A. True
B. False

B. False

Which of the following mutations is LEAST likely to result in harmful changes to cells?

A. nonsense mutations
B. missense mutation
C. silent mutation
D. frameshift mutations

C. silent mutation

According to the base pairing rules of DNA, if the sequence of bases on one strand was AGGCTTA, what would be the sequence of bases on the complementary strand?

A. TCCGAAT
B. ATTCGGA
C. AGGCTTA
D. CGGATTC

A. TCCGAAT

Why does transcription occur in the nucleus and not in the cytoplasm?

A. Codons are only found in the nucleus.
B. RNA cannot exist in the cytoplasm.
C. DNA cannot leave the nucleus.
D. Ribosomes cannot leave the nucleus.

C. DNA cannot leave the nucleus.

If the base sequence of template strand reads GCCATTAC, what is the base sequence of the mRNA?

A. CGGTAATG
B. CGGUAAUG
C. GCCAUUAC
D. CGGTUUTG

B. CGGUAAUG

What does "transfer RNA" actually transfer?

A. Codons
B. Transcripts
C. Ribosome
D. Amino acids

D. Amino acids

How many nucleotides in sequence are required to code for 10 amino acids?

A. 10
B. 30
C. 3
D. 20

B. 30

Duplication of the chromosomes by a cell occurs __________.

A. in the cytoplasm of a eukaryotic cell
B. whenever a cell makes protein
C. before a cell divides
D. to repair gene damage caused by mutation

C. before a cell divides

__________ are linked together at the centromere.

A. Daughter cells
B. Homologous chromosomes
C. Sister chromatids
D. Sex chromosomes

C. Sister chromatids

After fertilization, the resulting zygote undergoes _____.

A. binary fission
B. asexual reproduction
C. mitosis
D. meiosis

C. mitosis

In animals, meiosis __________.

A. produces four gamete cells
B. produces new diploid cells
C. produces new diploid individuals
D. produces four somatic (body) cells

A. produces four gamete cells

The function(s) of meiosis is/are _____.

A. reproduction (production of gametes)
B. growth and development
C. tissue repair/replacement of damaged cells
D. b and c, but not a
E. a, b, and c

A. reproduction (production of gametes)

Looking through a light microscope at a cell undergoing meiosis, you see that the chromosomes have joined into XX-shaped tetrads. These tetrads are lined up along a plane that runs through the center of the cell. This cell is in _____.

A. interphase
B. meiosis I
C. meiosis II
D. cytokinesis of meiosis II

B. meiosis I

Meiosis starts with _____ cells and produces _____ gametes.

A. diploid … haploid
B. diploid … diploid
C. haploid … haploid
D. haploid … diploid

A. diploid … haploid

Meiosis is typically accomplished in _____.

A. one step. A diploid cell divides to produce two

B.haploid gametes.
three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of four haploid gametes.

C. two steps. A diploid cell divides to produce two haploid gametes; these are then duplicated to produce a total of four gamete cells.

B.haploid gametes. three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of four haploid gametes.

The _____ separate in meiosis I; the _____ separate in meiosis II.

A. homologous chromosomes … sister chromatids
B. sister chromatids … homologous chromosomes
C. centrosomes … centromeres
D. sister chromatids … tetrads

A. homologous chromosomes … sister chromatids

Like mitosis, meiosis involves duplication of the chromosomes before division starts. However, there are __________ rounds of cell division during meiosis and __________ during mitosis.

A. two; none
B. two; one
C. four; one
D. four; two

B. two; one

Crossing happens during __________.

A. the movement of genetic material from one chromosome to a non-homologous chromosome
B. mitosis
C. meiosis
D. an independent assortment of chromosomes

C. meiosis

Random orientation of homologous pairs of chromosomes during meiosis I results in alternative arrangements that contribute to genetic variation in offspring. This is called __________.

A. crossing over
B. independent assortment
C. genetic variation
D. random fertilization

B. independent assortment

Dead or damaged cells are replaced by ________.

A. mitosis
B. binary fission
C. meiosis
D. syngamy

A. mitosis

The offspring produced via sexual reproduction are genetically ________ to the parents.

A. indifferent
B. identical
C. unique
D. parsimonious

C. unique

Which process specifically refers to a cell physically dividing into two cells?

A. Interphase
B. Mitosis
C. Cytokinesis
D. Meiosis

C. Cytokinesis

If mitosis makes somatic cells, what does meiosis make?

A. Body cells
B. Gonads
C. Homologs
D. Sex cells

D. Sex cells

How many chromosomes did you inherit from your father?

A. 24
B. 46
C. 23
D. 2

C. 23

What produces genetically unique daughter cells?

A. Meiosis
B. Mitosis
C. Both of these
D. Neither of these

A. Meiosis

Somatic cells are ________.

A. diploid (n)
B. diploid (2n)
C. haploid (2n)
D. haploid (n)

B. diploid (2n)

During which phase of the cell cycle are the chromosomes duplicated?

A. Cytokinesis
B. Meiosis
C. Mitosis
D. Interphase

D. Interphase

According to the American Cancer Society, what is the single best lifestyle choice that you can make to reduce your risk of cancer?

A. eat a healthy diet
B. take advantage of regular screenings for early detection of many kinds of cancer
C. don’t smoke
D. exercise regularly

C. don’t smoke

What type of cells undergo mitosis?

A. Gametes
B. Bacterial cells
C. Both of these
D. Neither of these

D. Neither of these

Upon fertilization, the egg and sperm fuse to form a single cell called a(n) ________

…

A(n) _____ is an inherited feature that varies from individual to individual.

character

A(n) _____ is one particular variation of a character.

trait

Most human genes come in alternate versions called _____.

alleles

If an organism has two non-identical version of a gene, the one that is expressed in the organism is called the _____ allele .

dominant

If an organism has two non-identical version of a gene, the one that is not expressed in the organism is called the _____ allele.

recessive

The physical traits of an organism are called its _____.

phenotype

The _____ is the genetic makeup of an organism.

genotype

Imagine that, in cats, eye color is controlled by a single gene and that black eyes are dominant to orange eyes. All the offspring of a cross between a black-eyed cat and an orange-eyed cat have black eyes. This means that the allele for black eyes is __________ the allele for orange eyes.

A. evolutionarily more fit than
B. recessive to
C. codominant to
D. dominant to

D. dominant to

What do we call a genetic cross that follows two separate characters, such as pea seed color and pea seed shape?

A. a monohybrid cross
B. a test cross
C. a dihybrid cross
D. a Punnett square

C. a dihybrid cross

Fur color in rabbits is controlled by multiple alleles. What does this mean?

A. This is an example of pleiotropy.
B. Rabbit fur color is controlled by a single gene, but there are multiple versions of that gene.
C. There are several genes that work together to determine a rabbit’s fur color.
D. All of the rabbit coat color alleles are co-dominant.

B. Rabbit fur color is controlled by a single gene, but there are multiple versions of that gene.

Why are linked genes inherited as a set rather than independently?

A. Linked genes are located far from each other on the same chromosomes, so they tend to move together.
B. Genes appear linked due to random chance.
C. Linked genes are located far from each other on the same chromosomes, so they tend to move separately.
D. Linked genes are located near each other on the same chromosomes, so they tend to move together.

D. Linked genes are located near each other on the same chromosomes, so they tend to move together.

What is a carrier?

A. an individual who is homozygous for a particular recessive trait
B. an individual who displays a mutant characteristic
C. an individual who is heterozygous for a particular recessive trait
D. an individual who displays a wild-type characteristic

C. an individual who is heterozygous for a particular recessive trait

Mendel’s Law of Independent Assortment states that __________.

A. each pair of alleles separates in a way that keeps them together
B. linked genes are on different chromosomes
C. if you cross an individual with a dominant trait with an individual who expresses the corresponding recessive trait, the dominant phenotype would be the most likely outcome
D. each pair of alleles segregates independently of the other pairs of alleles

D. each pair of alleles segregates independently of the other pairs of alleles

A breeder wants to set up a program to produce zebrafish with long fins. Having long fins is a dominant trait compared to the short fin wild type. Before she can market her zebrafish, she needs to perform a test cross on the long-finned fish she plans to use as a breeder. How can she tell whether her fish are homozygous or heterozygous for the long-finned trait?

A. Cross the long-finned fish with short-finned fish; if three-fourths of the offspring are long-finned and one-fourth are short-finned, the long-finned parent is homozygous.
B. Do several test crosses between the long-finned fish and the short-finned fish; if the offspring are always long finned, the long-finned parent is probably homozygous.
C. Cross the long-finned fish with short-finned fish; if half the offspring are long finned and half are short finned, the long-finned parent is homozygous.
D. Cross the long-finned fish with short-finned fish; if four-fifths of the offspring are long finned and one-fifth are short finned, the long-finned parent is homozygous.

B. Do several test crosses between the long-finned fish and the short-finned fish; if the offspring are always long finned, the long-finned parent is probably homozygous.

The inheritance pattern for red-green color blindness is different for males compared to females. Similar to the inheritance pattern for hemophilia in the royal families of Europe, red-green color blindness is rare in females although they can be carriers for this trait. Why is the inheritance pattern different for males and females?

A. The gene for this trait is located on the X chromosome.
B. The gene for this trait is located on the Y chromosome.
C. Males do not express this trait unless they inherit two copies of the red-green color blindness allele, while females express this trait even if they have inherited only one copy of the color blindness allele.
D. This is an example of pleiotropy.

A. The gene for this trait is located on the X chromosome.

What leads to an individual having too many or two few chromosomes?

A. Independent assortment
B. Homologous recombination
C. Crossing over
D. Nondisjunction

D. Nondisjunction

A true-breeding milk chocolate Easter bunny is crossed with a true-breeding dark chocolate Easter bunny. Assuming dark chocolate is dominant over milk chocolate and the traits segregate according to Mendelian genetics, which traits will the offspring express?

A. All Milk
B. 3 Milk to 1 Dark
C. 3 Dark to 1 Milk
D. All Dark

D. All Dark

A test cross is performed to determine if a specific individual is a carrier. The results generate a 50/50 phenotypic ratio. The test subject was therefore ________.

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

B. heterozygous

Assuming complete dominance, what is the expected phenotypic ratio of the offspring following the cross of two heterozygotes?

A. 1:1
B. 1:2:1
C. 4:1
D. 3:1

D. 3:1

The following F1 cross is made: BBGg × Bbgg. Which is not a possible outcome in the F2 generation?

A. BBGg
B. BbGg
C. BBgg
D. BbGG

D. BbGG

Assuming incomplete dominance, if a homozygous red-flowered plant is crossed with a homozygous white-flowered plant, what will be the color of the offspring?

A. Pink
B. White
C. Red
D. Red and white

A. Pink

How does antibiotic resistance evolve in bacterial populations?

A. Individual bacterial cells evolve in response to the presence of an antibiotic in their environment. These cells multiply. Eventually, antibiotic-resistant cells become common, which renders the antibiotic useless.
B. Over time, bacteria become stronger and more able to resist antibiotics.
C. In any population of bacteria, some individuals are more resistant to particular antibiotics and some individuals are less resistant. In the presence of an antibiotic, susceptible individuals die off. Over time, the frequency of resistant bacteria within the population increases.
D. The presence of antibiotics in their environment triggers genetic changes in bacteria that are passed on to subsequent generations.

C. In any population of bacteria, some individuals are more resistant to particular antibiotics and some individuals are less resistant. In the presence of an antibiotic, susceptible individuals die off. Over time, the frequency of resistant bacteria within the population increases.

A comparison of bat wings, porpoise flippers, and human arms shows that __________.

A. there must have been independent evolution of similar features in unrelated species
B. they evolved from a common ancestor
C. each type of limb has been designed for its current use and has a unique structure optimized for its environment
D. there must be one optimum limb structure that would eventually evolve even in unrelated organisms

B. they evolved from a common ancestor

Imagine that you start with a population of red, white, and blue flowers, a trait controlled by genetics. If you always cut blue flowers before they have a chance to reproduce, the number of blue flowers will change from generation to generation; however, the gene pool will still remain constant.

A. True
B. False

B. False

The human immune system cannot effectively suppress the HIV virus on its own. What key feature of HIV makes it so hard to beat?

A. The HIV virus can survive harsh conditions for years as a dormant particle.
B. The HIV virus has an extremely high rate of mutation.
C. The HIV virus replicates its genome with a great deal of precision (i.e., has a low mutation rate).
D. The HIV virus has a special protein coat that protects it from attack by all known human immune defenses.

B. The HIV virus has an extremely high rate of mutation.

Imagine that four people are infected with HIV from a common source (an infected blood sample). Initially, the patients’ HIV populations are genetically identical. By the time they develop full-blown AIDS, how would the viral populations of the four patients compare?

A. Each patient’s viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses.
B. The viral populations would still be genetically identical to each other and would be unchanged from the time of infection.
C. The viral populations would have evolved to a new and more dangerous strain, but that strain would be identical across all four patients. This is the strain of virus found in every person suffering full-blown AIDS.

A. Each patient’s viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses.

As proposed by Darwin, what sorts of traits are favored by natural selection?

A. Any traits that are produced by mutation and can be inherited.
B. Traits that reduce the number of offspring an individual produces, thus helping to reduce the struggle for existence in the next generation.
C. Traits that reduce the mutation rate and cut down on unnecessary variation within populations.
D. Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

D. Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

Natural selection is best described as _____.

A. a creative force that efficiently develops the best and simplest solutions for all problems in nature
B. a forward-looking process that anticipates future problems and designs the necessary tools to solve them through mutation
C. a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations
D. a completely random and unpredictable process of change, or evolution

C. a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations

HIV has become an important source of mortality for humans. If AIDS persists as a major factor for humans for many generations in the future, natural selection theory predicts that _____.

A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time
B. AIDS should gradually become less variable with a lower mutation rate
C. humans will develop weaker immune systems as an evolutionary response to natural selection
D. individual humans will evolve to become immune to AIDS as long as they are exposed to it as young children

A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time

Individuals with variations that make them best suited to their environment will, on average, be more likely to ________.

A. be larger
B. survive and reproduce
C. evolve
D. change over time

B. survive and reproduce

The older fossils are typically found in the ________ sediments.

A. finer
B. coarser
C. upper
D. lower

D. lower

What is the name for the study of the geographic distribution of species?

A. Taxonomy
B. Ecology
C. Biogeography
D. Systematics

B. Ecology

Comparing the body structures of organisms to find evidence of a shared evolutionary history is called ________.

A. relativistic physiology
B. analogous reconstruction
C. outgrouping
D. comparative anatomy

D. comparative anatomy

Darwinian fitness is measured only in terms of the number of healthy offspring produced.

A. True
B. False

A. True

Which of the following came first?

A. The work of Scottish geologist Charles Lyell suggested that Earth was very old and changed gradually through natural processes such as earthquakes and erosion.
B. French naturalist Jean-Baptiste Lamarck proposed that life evolves through physical changes that enable organisms to succeed in their environment.
C. As the ship naturalist aboard the HMS Beagle, Darwin collected evidence that eventually led to his ideas about natural selection.
D. Scientists began to suspect that fossils might represent extinct ancient forms of modern organisms.

D. Scientists began to suspect that fossils might represent extinct ancient forms of modern organisms.

What is radiometric dating?

A. The process of determining the age of the fossils based on which layer in the rock it is found
B. The process of determining the age of the fossils using radio waves
C. The mineralization process by which living things are turned into fossils
D. The process of determining the age of the fossils from radioactive isotopes

D. The process of determining the age of the fossils from radioactive isotopes