Biology Ch. 9

Chromosomes that look alike and carry the same sequence of genes for the same traits are
A. the X and Y chromosome.
B. all the autosomes.
C. homologous chromosomes.
D. found in females only.
E. found in males only.

C Homologous chromosomes

Meiosis is a process that produces
A. sperm cells.
B. egg cells.
C. gametes.
D. haploid cells.
E. All answers are correct.

E. All answers are correct

The process by which a bacterium uses a sex pilus to transfer genetic information to another bacterium is
A. meiosis.
B. mutation.
C. mitosis.
D. conjugation.
E. sexual reproduction.

D. conjugation.

Sexual reproduction is important to the survival of a species in a changing environment because
A. sexual reproduction requires less overall energy expenditure than asexual reproduction.
B. sexual reproduction produces genetically different individuals.
C. sexual reproduction requires only one individual.
D. sexual reproduction produces genetically-identical individuals.
E. All answers are correct.

B. Sexual reproduction produces genetically different individuals

2n is an abbreviation for
A. diploid.
B. gametes.
C. haploid.
D. mitosis.
E. meiosis

A. Diploid

Diploid means having
A. one complete set of chromosomes.
B. three complete sets of chromosomes.
C. two complete sets of chromosomes.
D. two chromosomes in each somatic cell.
E. two chromosomes in each gamete.

C. Two complete sets of chromosomes

If human gametes were diploid
A. the products of fertilization would have the same number of chromosomes as their parents.
B. the products of fertilization would have fewer chromosomes than their parents.
C. fertilization could not occur.
D. the products of fertilization would have more chromosomes than their parents.
E. the embryo would be diploid.

D. the products of fertilization would have more chromosomes than their parents.

1n is an abbreviation for
A. haploid.
B. somatic cells.
C. diploid.
D. mitosis.
E. meiosis.

A. Haploid

In humans, germ cells are located in
A. bone marrow.
B. blood.
C. all cells.
D. all tissues.
E. testes and ovaries.

E. Testes and ovaries

A diploid germ cell will produce cells that have reduced the chromosome number by half, generating four haploid nuclei in
A. fertilization.
B. mitosis.
C. meiosis.
D. replication.
E. mutation.

C. meiosis

After the completion of meiosis in humans, a diploid germ cell has produced cells with half the original chromosome number, generating __________ haploid nuclei.
A. 2
B. 3
C. 4
D. 23
E. 46

C. 4

The process that merges the gametes from two parents is
A. fertilization.
B. meiosis.
C. mitosis.
D. mutation.
E. conjugation.

A. Fertilization

A zygote is
A. a haploid cell.
B. a gamete.
C. a direct product of meiosis.
D. All answers are correct.
E. a diploid cell.

E. A diploid cell

Sexual reproduction includes
A. mitosis, gamete formation, and fertilization.
B. mitosis, meiosis, and gamete formation.
C. meiosis, gamete formation, and fertilization.
D. mitosis, fertilization, and meiosis.
E. None of the answers are correct.

C. Meiosis, Gamete formation, and fertilization

Mitotic cell division creates identical copies by replicating a cell’s DNA __________ and then dividing ____________.
A. once, twice
B. twice, once
C. twice, twice
D. once, once
E. None of the answers are correct.

D. Once, once

Meiotic cell division replicates a cell’s DNA ____________ and then divides ______________.
A. twice, once
B. once, twice
C. twice, twice
D. once, once
E. None of the answers are correct.

B. Once, twice

Human cells have
A. 23 pairs of chromosomes.
B. 23 chromosomes.
C. 46 pairs of chromosomes.
D. 2 pairs of sex chromosomes.
E. one pair of autosomes.

A. 23 Pairs of chromosomes

The human chromosomes that do not determine gender are
A. not found in pairs.
B. the "X" and "Y" chromosomes.
C. autosomes.
D. called sex chromosomes.
E. None of the answers are correct.

C. Autosomes

The chromosomal designation for a human male is
A. XX.
B. XO.
C. XY.
D. YY.
E. XXX.

C. XY

The chromosomal designation for a human female is
A. XYY.
B. XY.
C. YY.
D. XX.
E. None of the answers are correct.

D. XX

The X chromosome is
A. larger than the Y chromosome.
B. smaller than the Y chromosome.
C. the same size as the Y chromosome.
D. genetically identical to the Y chromosome.
E. larger and genetically identical to the Y chromosome.

A. Larger than the Y chromosome

The Y chromosome
A. is larger than the X chromosome.
B. contains more genes than the X chromosome.
C. is the same size as the X chromosome.
D. is smaller than the X chromosome.
E. is genetically identical to the X chromosome.

D. Is smaller than the X chromosome

In meiosis, DNA replicates during
A. prophase I.
B. prophase II.
C. interphase prior to meiosis II.
D. interphase prior to meiosis I.
E. both prophase I and prophase II.

D. Interphase prior to meiosis I.

In meiosis, homologous chromosomes align next to one another during
A. interphase I.
B. metaphase II.
C. prophase I.
D. metaphase I.
E. prophase II.

C. prophase I.

In meiosis, homologous chromosomes separate during
A. prophase I.
B. prophase II.
C. anaphase I.
D. metaphase I.
E. anaphase II.

C. Anaphase I.

In meiosis I, cytokinesis usually occurs after telophase I and produces
A. one diploid cell with sister chromatids still attached.
B. two haploid cells with sister chromatids still attached.
C. four haploid cells.
D. two diploid cells.
E. one haploid cell.

B. Two haploid cells with sister chromatids still attached.

In meiosis, paired homologs align down the center of the cell during
A. metaphase I.
B. prophase I.
C. prophase II.
D. metaphase II.
E. anaphase II.

A. metaphase I.

In meiosis, chromosomes containing sister chromatids (not homologous chromosomes) align along the center of the cell during
A. prophase I.
B. prophase II.
C. interphase II.
D. metaphase I.
E. metaphase II.

E. metaphase II.

In meiosis, the separated sister chromatids move to opposite poles of the cell during
A. metaphase I.
B. metaphase II.
C. anaphase I.
D. telophase I.
E. anaphase II.

E. Anaphase II.

30. In meiosis II, cytokinesis results in the production of
A. two haploid daughter cells.
B. four diploid daughter cells.
C. four haploid daughter cells.
D. two diploid daughter cells.
E. one daughter cell identical to the parent cell that underwent meiosis.

C. Four haploid daughter cells

Sexual reproduction and meiosis generate genetic variety by
A. random fertilization.
B. All answers are correct.
C. independent assortment.
D. crossing over.

B. All answers are correct

The process by which homologous chromosomes exchange genetic material
A. is crossing over.
B. is random fertilization.
C. occurs only in bacteria.
D. occurs only in animals.
E. is independent assortment.

A. Is crossing over.

Alternate forms of the same gene
A. do not exist.
B. are alleles.
C. are homologs.
D. are sister chromatids.
E. do not occur in the same individual.

B. Are alleles

What process creates daughter cells with a mixture of paternal and maternal chromosomes?
A. asexual reproduction
B. semi-conservative replication
C. random fertilization
D. independent assortment
E. mutation

D. independent assortment

A gamete having more than one complete set of chromosomes
A. cannot be produced by meiosis.
B. cannot participate in fertilization.
C. is polyploid.
D. will undergo mitosis.
E. is not yet through meiosis.

C. Is polyploid

When chromosomes fail to separate at either the first or second meiotic division, this
A. is known as crossing over.
B. results in a sperm or egg cell with an abnormal number of chromosomes.
C. is known as translocation.
D. results in a failure to produce gametes.
E. results in arrest during meiosis.

B. Results in a sperm or egg cell with an abnormal number of chromosomes

Nondisjunction may cause
A. trisomy 21.
B. Turner syndrome.
C. Jacobs syndrome.
D. All answers are correct.
E. Klinefelter syndrome.

D. All answers are correct

What is an advantage of sexual reproduction over asexual reproduction?
A. genetic variability during an ecological disaster
B. genetic variability when the environment is stable
C. faster reproduction
D. requirement of less energy
E. simpler form of reproduction

A. genetic variability during an ecological disaster

Why does sexual reproduction produce more genetic variability in a population?
A. Offspring are genetically identical to one parent.
B. During sex, adults can exchange genetic material thus increasing their variability.
C. Organisms arising from sexual reproduction can change their genetic material in response to environmental changes.
D. Sexually-reproducing organisms mutate more rapidly than asexually reproducing organisms.
E. Offspring are a genetic mix of both parents.

E. Offspring are a genetic mix of both parents.

Homologous chromosomes contain the same ____ but may contain different ____.
A. alleles, genes
B. sister chromatids, genes
C. alleles, sister chromatids
D. genes, sister chromatids
E. genes, alleles

E. Genes, alleles

People who have a single X chromosome are female, while those with XXY sex chromosomes are males. In order to be a female, a human

Cannot have a Y chromosome

Why is it essential that meiosis produce haploid cells?
A. so that the number of chromosomes will double each generation
B. to produce haploid offspring
C. to prevent the number of chromosomes from doubling each generation
D. to produce diploid gametes
E. to allow asexual reproduction

C. To prevent the number of chromosomes from doubling each generation

If a diploid cell goes through meiosis it will generate
A. two haploid cells.
B. four diploid cells.
C. two diploid cells.
D. four haploid cells.
E. This is not possible.

D. Four haploid cells

If a haploid cell goes through meiosis it will generate

This is not possible

If a diploid cell goes through mitosis it will generate
A. four haploid cells.
B. two diploid cells.
C. two haploid cells.
D. four diploid cells.
E. This is not possible

B. two diploid cells.

If a haploid cell goes through mitosis it will generate

two haploid cells

When a human egg ovulates, it arrests in metaphase II until it is fertilized by a sperm. How many chromosomes are present in the egg at metaphase II?
A. 46
B. 2 with sister chromatids still attached
C. 4
D. 23 with sister chromatids still attached
E. 1

D. 23 with sister chromatids still attached

A diploid cell with 4 chromosomes would produce which of the following after meiosis?
A. Two genetically-distinct types of haploid gametes
B. Two genetically-distinct types of diploid gametes
C. Four genetically-distinct types of haploid gametes
D. Four genetically-distinct types of diploid gametes
E. Four genetically-identical diploid gametes

C. Four genetically-distinct types of haploid gametes

A diploid cell with 6 chromosomes would produce which of the following after meiosis?
A. Four genetically-distinct types of haploid gametes
B. Two genetically-distinct types of diploid gametes
C. Four genetically-distinct types of diploid gametes
D. Eight genetically-distinct types of haploid gametes
E. Eight genetically-identical haploid gametes

A. Four genetically-distinct types of haploid gametes

Genes A and B are on the same chromosome. What gametes could an individual with the allele combination AABB produce?

AB

Genes A and B are on the same chromosome. If a person has one chromosome with the alleles AB and a second chromosome with the alleles ab, how could they produce a gamete with a chromosome containing the alleles Ab or aB?

crossing over

Which of the following will occur in meiosis but not in mitosis?
A. metaphase
B. cytokinesis
C. crossing over
D. DNA replication
E. chromosome condensation

C. Crossing over

If a chromosome in one of your bone cells becomes mutated, you will not pass this mutation onto your children because
A. somatic cells cannot undergo mitosis.
B. germ cells cannot undergo meiosis.
C. germ cells cannot undergo mitosis.
D. somatic cells cannot undergo meiosis.

D. Somatic cells cannot undergo meiosis

Most cultivated bananas are triploid. How could these be generated from diploid parent banana plants?

nondisjunction in meiosis followed by normal fertilization

If you mate a donkey (2n = 62) with a horse (2n = 64) you get a mule. A mule is sterile and cannot produce gametes by meiosis because
A. they contain too few chromosomes.
B. they have an odd number of chromosomes.
C. they have an even number of chromosomes.
D. they contain too many chromosomes.
E. they lack genes that are essential for life.

B. they have an odd number of chromosomes.

In humans, the sex of a child is determined by
A. the sex chromosome in the egg.
B. the number of autosomes in the sperm.
C. the number of autosomes in the egg.
D. the sex chromosome in the sperm.
E. the number of X chromosomes in the egg.

D. The sex chromosome in the sperm

For a plant to produce diploid sperm and egg ____ must occur during ____.

nondisjunction; meiosis

If a diploid sperm fertilizes a diploid egg it will produce a _____zygote.

tetraploid

In the section "Investigating Life: A New Species Is Born, but Who’s the Daddy?", Tragopogon mirus is a hybrid of T. dubius and T. porrifolius. Based on the figure, T. mirus has

12 chromosomes from T. dubius and 12 chromosomes from T. porrifolius

In the section "Investigating Life: A New Species Is Born, but Who’s the Daddy?", T. mirus would normally produce gametes with __ chromosomes.

12

In the section "Investigating Life: A New Species Is Born, but Who’s the Daddy?", T. miscellus has

arisen more than once with T. pratensis and T. dubius both being the female parent.

In the section "Investigating Life: A New Species Is Born, but Who’s the Daddy?", pollen contains ___ that produce ___.

gametophtes, sperm

Mitosis occurs in germ cells throughout life.

FALSE

There are two divisions in meiosis resulting in four daughter cells.

TRUE

The number of chromosomes in a daughter cell produced by mitosis is the same number of chromosomes in the parent cell.

TRUE

The number of chromosomes in a daughter cell produced by meiosis is the same as the number of chromosomes in the parent cell.

FALSE

Mitosis does not require that homologous chromosomes align with one another.

TRUE

Meiosis requires that homologous chromosomes align with one another so that crossing over may occur.

TRUE

If a human zygote has either 45 or 47 chromosomes it was caused by random fertilization.

FALSE

If a human zygote has either 45 or 47 chromosomes it was caused by nondisjunction.

TRUE

A male with an extra chromosome (XXY) has Turner syndrome.

FALSE

A female missing an X chromosome (XO) has Turner syndrome.

TRUE

If a woman in her late forties wants to have a baby and seeks medical advice, she will be advised that she is at a greater risk of having a baby with Down syndrome.

TRUE

Identical twins result from a single fertilization to form a zygote, which then clones itself.

TRUE

Fraternal twins (dizygotic) result from the fertilization of
A. two eggs and two sperm.
B. two eggs and one sperm.
C. one egg and two sperm.
D. one egg and one sperm.
E. two eggs and one sperm OR one egg and two sperm.

A. Two eggs and two sperm

Genetic information is passed from one generation to the next through
A. DNA.
B. asexual reproduction.
C. sexual reproduction.
D. gametes.
E. All answers are correct.

E. All answers are correct

What two processes results in genetically-identical products?
A. mitosis and meiosis
B. meiosis and asexual reproduction
C. meiosis and sexual reproduction
D. mitosis and sexual reproduction
E. mitosis and asexual reproduction

E. mitosis and asexual reproduction

What two processes results in genetically-different products?
A. mitosis and meiosis
B. mitosis and asexual reproduction
C. meiosis and asexual reproduction
D. meiosis and sexual reproduction
E. mitosis and sexual reproduction

D. meiosis and sexual reproduction

What creates genetically different offspring in both asexual and sexual reproduction?

mutations

Haploid cells lack which of the following?

homologous chromosomes

If the allele for presence or absence of hair is located on the maternal chromosomes #3, then the same alleles is located on the paternal chromosome #3.

FALSE

If the gene for presence or absence of hair is located on the maternal chromosomes #3, then the same gene is located on the paternal chromosome #3.

TRUE

Genetic variability will not occur among offspring if crossing over does not occur during prophase I of meiosis.

FALSE

Genetic variability will not occur among offspring if independent assortment does not occur during anaphase I of meiosis

FALSE