Which of the following statements is correct in comparing sexual and asexual reproduction? A) Asexual reproduction, but not sexual reproduction, is characteristic of only plants and fungi. B) In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.

C) In asexual reproduction, offspring are produced by fertilization without meiosis. D) Asexual reproduction produces only haploid offspring.

B

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?
A) prophase
B) metaphase

C) anaphase
D) interphase

B

Which of the following statements is true of a species that has a chromosome number of 2n = 16?
A) The species is diploid with 32 chromosomes per cell.
B) The species has 16 sets of chromosomes per cell.

C) Each diploid cell has eight homologous pairs of chromosomes. D) A gamete from this species has four chromosomes.

C

Eukaryotic sexual life cycles show tremendous variation. Which of the following characteristics do all sexual life cycles have in common?

1. Alternation of generations
2. Meiosis
3. Fertilization
4. Gametes
5. Spores

A) I, II, and IV
B) II, III, and IV
C) II, IV, and V
D) I, II, III, IV, and V

B

Which of the following processes occurs in a plant's sexual life cycle? A) sporophytes produce gametes by meiosis
B) gametophytes produce gametes by mitosis
C) gametophytes produce gametes by meiosis

D) sporophytes produce gametes by mitosis

B

Which of the following statements describes an example of alternation of generations? A) A grandparent and grandchild each have dark hair, but the parent has blond hair.
B) A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).

C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote.
D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis.

B

A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?
A) It must be human.
B) It must be an animal.

C) It reproduces sexually.
D) It produces gametes with 23 chromosomes.

D

A triploid cell contains three sets of homologous chromosomes. If a cell of a diploid species that normally has 42 chromosomes per cell is triploid, this cell would be expected to have which of the following sets of chromosomes?
A) 63 chromosomes in 31 1/2 pairs

B) 63 chromosomes in 21 sets of 3
C) 63 chromosomes, each with 3 sister chromatids
D) 21 chromosome pairs and 21 unique chromosomes

B

Which of the following processes might produce a human zygote with 45 chromosomes? A) an error in meiotic anaphase occurring in either an egg or sperm
B) failure of the egg nucleus to be fertilized by the sperm
C) failure of an egg to complete meiosis II

D) incomplete cytokinesis during spermatogenesis after meiosis I

A

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?
A) length and position of the centromere only

B) length, centromere position, and staining pattern only
C) length, centromere position, staining pattern, and traits coded for by their genes D) They have nothing in common except that they are X-shaped.

C

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?
A) length and position of the centromere only

B) length, centromere position, and staining pattern only
C) length, centromere position, staining pattern, and traits coded for by their genes D) They have nothing in common except that they are X-shaped.

C

Which of the life cycles is typical for most fungi and some protists? A) I only
B) II only
C) III only

D) I and II

B

In a life cycle such as that shown in part III of the figure above, if the zygote's chromosome number is ten, which of the following statements will be true?
A) The sporophyte's chromosome number per cell is ten and the gametophyte's is five.
B) The sporophyte's chromosome number per cell is five and the gametophyte's is ten.

C) The sporophyte and gametophyte each have ten chromosomes per cell. D) The sporophyte and gametophyte each have five chromosomes per cell.

A

Which of the following characteristics do homologous chromosomes exhibit? A) They carry information for different traits.
B) They carry information for the same traits.
C) They carry the same alleles.

D) They align on the metaphase plate in meiosis II.

B

Many organisms spend most of their life cycle in the diploid state. If meiosis produces haploid cells, how is the diploid number restored for these types of organisms?
A) by DNA replication
B) through the transcription of DNA to RNA

C) by synapsis of the homologous pairs of chromosomes during prophase of meiosis I D) by fertilization

D

Which of the following statements is correct regarding the human X chromosomes? A) It is present in every somatic cell of males and females.
B) It is the same size as other chromosomes and has the same number of genes.
C) It carries genes that determine an individual's biological sex.

D) It is referred to as an autosome.

C

Which of the following statements correctly describes a karyotype? A) It is a display of all of the cell types in an organism.
B) It is an organized image of a cell's chromosomes.
C) It reveals the appearance of an organism.

D) It is a display of a cell's mitotic stages.

B

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents?
A) It has half the amount of DNA as the cell that began meiosis.
B) It has half the chromosomes but twice the DNA of the parent cell.

C) It has one-fourth the DNA and one-half the chromosomes as the parent cell. D) It is genetically identical to another cell formed from the same meiosis I event.

A

The somatic cells of a privet shrub each contain a total of 46 chromosomes. How do the chromosomes of this plant differ from the chromosomes of humans, who also have a total of 46? A) Privet shrub cells cannot reproduce sexually.
B) Privet shrub sex cells have chromosomes that can synapse with human chromosomes in the laboratory.
C) Genes of privet shrub chromosomes are significantly different than those in humans.
D) Privet shrubs must be metabolically more like animals than like other shrubs.

C

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?
A) The cells are diploid, and the chromosomes are each composed of a single chromatid.
B) The cells are diploid, and the chromosomes are each composed of two chromatids.

C) The cells are haploid, and the chromosomes are each composed of a single chromatid. D) The cells are haploid, and the chromosomes are each composed of two chromatids.

D

How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I?
A) The cells have half the number of chromosomes and half the amount of DNA.
B) The cells have the same number of chromosomes and half the amount of DNA.

C) The cells have half the number of chromosomes and one-fourth the amount of DNA. D) The cells have half the amount of cytoplasm and twice the amount of DNA.

C

Which of the following events happens at the conclusion of meiosis I? A) Homologous chromosomes of a pair are separated from each other.
B) The chromosome number per cell remains the same.
C) Sister chromatids are separated.

D) Four daughter cells are formed.

A

During which of the following processes do sister chromatids separate from each other? A) during meiosis I only
B) during meiosis II only
C) during both mitosis and meiosis I

D) during both mitosis and meiosis II

D

Which of the following processes occurs in meiosis but not in mitosis? A) chromosome replication
B) synapsis of chromosomes
C) alignment of chromosomes at the equator

D) condensation of chromosomes

B

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred?
A) meiosis II
B) anaphase II

C) prophase I
D) the separation of homologs

C

For the following questions, match the key event of meiosis with the stages listed below.

1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

V. Prophase II VI. Metaphase II VII.Anaphase II VIII. Telophase II

31) Homologous chromosomes are aligned at the equator of the spindle. A) I
B) II
C) IV

D) VI

B

For the following questions, match the key event of meiosis with the stages listed below.

1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

V. Prophase II VI. Metaphase II VII.Anaphase II VIII. Telophase II

Centromeres of sister chromatids disjoin and chromatids separate. A) III
B) IV
C) V

D) VII

D

Which sample of DNA might be from a cell that stopped the process of cell division in G0

phase of the cell cycle prior to meiosis? A) I
B) II
C) III

D) either I or II

A

Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior

to meiosis? A) I
B) II
C) III

D) both I and II

B

Which sample of DNA might represent a zygote? A) I
B) II
C) III

D) either I or II

A

Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm?
A) four
B) two

C) eight
D) a diploid number

B

Which of the following processes occur during meiosis but not mitosis? A) Haploid cells fuse to form diploid cells.
B) Haploid cells multiply into more haploid cells.
C) Diploid cells form haploid cells.

D) A diploid cell combines with a haploid cell.

C

During which of the following phases of meiosis do homologous chromosomes separate? A) anaphase II
B) prophase I
C) mitosis

D) anaphase I

D

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?
A) Homologous chromosomes align on the metaphase plate in meiosis II.
B) Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. C) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

D) Crossing over of chromosomes takes place in meiosis II.

C

Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism?
A) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I.

B) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II.
C) DNA replication takes place prior to mitosis, but not before meiosis I.
D) Only meiosis I results in daughter cells that contain identical genetic information.

A

Crossing over of chromosomes normally takes place during which of the following processes?
A) meiosis II
B) meiosis I

C) mitosis
D) mitosis and meiosis II

B

Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I?
A) Each chromosome is paired with a homologous chromosome.
B) Each chromosome consists of two sister chromatids joined by a centromere.

C) Each chromosome consists of a single strand of DNA.
D) Each chromosome is joined with its homologous pair to form a synaptonemal complex.

B

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?
A) metaphase of mitosis
B) metaphase I of meiosis

C) telophase II of meiosis
D) metaphase II of meiosis

B

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?
A) anaphase I
B) telophase I

C) anaphase II
D) telophase II

C

During which of the following processes does independent assortment of chromosomes occur?
A) in meiosis I only
B) in meiosis II only

C) in mitosis and meiosis I
D) in mitosis and meiosis II

A

For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes based on the independent assortment of chromosomes during meiosis?
A) 23

B) 46
C) about 1,000
D) about 8 million

D

Independent assortment of chromosomes is a result of which of the following processes? A) the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I
B) the random combinations of eggs and sperm during fertilization

C) the random distribution of the sister chromatids to the two daughter cells during anaphase II D) the diverse combination of alleles that may be found within any given chromosome

A

Which of the following processes occurs when homologous chromosomes cross over in meiosis I?
A) Two sister chromatids get tangled, resulting in one re-sequencing its DNA.
B) Two sister chromatids exchange identical pieces of DNA.

C) Corresponding segments of non-sister chromatids are exchanged.
D) Maternal alleles are "corrected" to be like paternal alleles and vice versa

C

How does natural selection apply to sexual reproduction as opposed to asexual reproduction? A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction.
B) Sexual reproduction results in the greatest number of new mutations.

C) Sexual reproduction allows the greatest number of offspring to be produced. D) Sexual reproduction utilizes far less energy than asexual reproduction.

A

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. In addition to mutations, how might genetic diversity be generated in this species?
A) crossing over only

B) independent assortment only
C) crossing over and random fertilization D) nothing else

C

Which of the following processes facilitates the fastest way for organisms to adapt to a changing environment?
A) mutation
B) asexual reproduction

C) sexual reproduction
D) mitosis

C

magine that there are 25 different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment?

A) The sexually reproducing species is likely to thrive.
B) The asexually reproducing species is likely to thrive.
C) Sexually and asexually reproducing species are equally likely to thrive. D) Neither species will be able to thrive.

A

In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the following explanations correctly identifies the process and supports the claim that heritable information is passed from one generation to another?
A) During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced.

B) Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population.
C) In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

D) Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell.

C

Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms. Which of the following statements best represents the connection between reproduction and evolution?
A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity.
B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization.
C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution.
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

D

A human cell containing 22 autosomes and a Y chromosome is A) a sperm.
B) an egg.
C) a zygote.

D) a somatic cell of a male.

A

The two homologs of a pair move toward opposite poles of dividing cell during A) mitosis.
B) meiosis I.
C) meiosis II.

D) fertilization.

B

Meiosis II is similar to mitosis in that
A) sister chromatids separate during anaphase. B) DNA replicates before the division.
C) the daughter cells are diploid.
D) homologous chromosomes synapse.

A

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA

content of the same cell at metaphase of meiosis I will be A) 0.25x.
B) 0.5x.
C) x.

D) 2x.

D

If we continue to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II will be
A) 0.25x.
B) 0.5x.

C) x.
D) 2x.

C