Deck 11: Meiosis: the Cellular Basis of Sexual Reproduction

Question 1

DNA replication occurs ____.

A) during interphase before meiosis
B) during prophase I of meiosis
C) during prophase II of meiosis
D) between meiosis I and meiosis II
E) during interkinesis

Answer 1

A

Question 2

Human diploid cells have ____ chromosomes, while human gametes have ____ chromosomes.

A) 46; 23
B) 23; 46
C) 96; 48
D) 48; 96
E) 46; 92

Answer 2

A

Question 3

Sexual reproduction has an advantage over asexual reproduction by ____.

A) requiring an interaction between two individuals
B) creating more genetic diversity
C) ensuring a greater number of progeny
D) keeping the number of chromosomes constant more effectively
E) allowing for the production and use of gametes

Answer 3

B

Question 4

For humans, which parent's gamete will determine the sex of the child?

A) The father, because his gametes only contain the Y chromosome.
B) The mother, because her gametes only contain the X chromosome.
C) The father, because his gametes can contain either the X or the Y chromosome.
D) The mother, because her gametes can contain either the X or the Y chromosome.
E) Either parent, because the random mixing of gametes determines the sex of the child.

Question 5

If the diploid number of chromosomes in mouse somatic cells is 40, how many chromosomes are present during prophase I?

A) 40, each composed of a single paternal or maternal chromosome
B) 80, each composed of a pair of homologous chromosomes
C) 20, each composed of a single sister chromatid
D) 80, each composed of a single sister chromatid
E) 40, each containing a pair of sister chromatids

Question 6

Synapsis refers to the ____.

A) crossing-over between homologous chromosomes
B) alignment of homologous chromosomes along the equatorial plane
C) alignment of sister chromatids along the equatorial plane
D) pairing of homologous chromosomes during prophase I
E) pairing of sister chromatids during prophase II

Question 7

A homologous chromosome pair is best described as two chromosomes having ____.

A) the same genes in the same order, but possibly having different alleles of those genes
B) the same alleles of the same genes in the same order
C) the same alleles of the same genes in a different order
D) different alleles of the same genes arranged in a different order
E) identical DNA sequences

Question 8

Egg and sperm cells are ____.

A) sporophytes
B) gametes
C) gametophytes
D) diploid
E) somatic cells

Question 9

Homologous chromosomes ____.

A) are found in somatic cells and gametes
B) align along the equatorial plane during metaphase II
C) are replicated during interkinesis
D) contain a maternal and paternal chromosome
E) are preserved in each daughter cell produced by meiosis

Question 10

Homologous chromosomes undergo recombination during ____.

A) prophase II
B) metaphase I
C) metaphase II
D) both prophase I and II
E) prophase I

Question 11

The daughter cells produced by meiosis are ____.

A) identical to the parent, but genetically different from each other
B) identical to each other, but genetically different from the parent
C) genetically different from the parent and each other
D) genetically identical to the parent and each other
E) genetically different from each other, but with the same chromosome number as the parent

Question 12

Which statement describes a difference between meiosis I and meiosis II?

A) DNA is replicated during meiosis II, but not during meiosis I.
B) Homologous chromosomes separate during meiosis I; sister chromatids separate during meiosis II.
C) Meiosis I produces diploid cells; meiosis II produces haploid cells.
D) Chromosomes align along the equatorial plane of the cell in meiosis I, but not in meiosis II.
E) Crossing-over occurs during meiosis II, but not during meiosis I.

Question 13

The formation of gametes is called ____.

A) gametogenesis
B) mitosis
C) gametosis
D) fertilization
E) reproduction

Question 14

During prophase I of meiosis, each chromosome consists of ____.

A) one single-stranded DNA molecule
B) two sister chromatids
C) one sister chromatid
D) four sister chromatids
E) one double-stranded DNA molecule

Question 15

The chromosome number is halved by ____ and restored by ____.

A) independent assortment; meiosis
B) mitosis; meiosis
C) meiosis; mitosis
D) meiosis; fertilization
E) mitosis; fertilization

Question 16

Which meiotic phase is matched with the mitotic phase it most closely represents, except for the halving of chromosome number in the meiotic phase?

A) anaphase I and anaphase
B) anaphase II and anaphase
C) metaphase I and metaphase
D) interkinesis and telophase
E) metaphase II and prophase

Question 17

Meiosis occurs in the ____.

A) testes only
B) ovaries only
C) somatic cells
D) synaptonemal complex
E) gonads

Question 18

Sexual reproduction involves ____.

A) one diploid cell fertilizing a haploid cell
B) the union of two somatic cells
C) the union of male and female gametes
D) a single mitotic division of the parent cell to produce a daughter cell
E) the union of two gametes to produce a haploid zygote

Question 19

If a normal diploid germ cell in a bird has eight chromosomes, then ______.

A) there are eight homologous pairs of chromosomes per diploid germ cell
B) there are eight chromatids per diploid germ cell after DNA replication
C) there are four chromosomes per cell after the first meiotic division and cytokinesis
D) there are eight chromosomes in the sperm cells made from this diploid germ cell
E) there are eight copies of each chromosome in this diploid germ cell

Question 20

Alleles are ____.

A) sex chromosomes
B) somatic cells
C) crossover sites
D) attachment sites for microtubules
E) different versions of the same gene

Question 21

Which statement describes chromosomes?

A) Chromosomes are always spread out as chromatin.
B) Chromosomes are always condensed.
C) Homologous chromosomes have the same genes, but can have different alleles.
D) Homologous chromosomes always have the same alleles.
E) Chromosomes always consist of two sister chromatids.

Question 22

Nondisjunction during meiosis I results in ____.

A) the generation of an extra daughter cell
B) a change in the status of a daughter cell from diploid to haploid
C) a change in the status of a daughter cell from haploid to diploid
D) one pole of the cell receiving neither member of a homologous pair of chromosomes
E) a gamete that cannot fuse with another gamete

Question 23

What is the name of the period of time that separates meiosis I and meiosis II?

A) telophase II
B) interkinesis
C) prophase II
D) interphase
E) telophase I

Question 24

When do chromosomes line up at the metaphase plate in pairs?

A) metaphase I
B) prophase I
C) metaphase II
D) anaphase I
E) prometaphase II

Question 25

Sex chromosomes are ____.

A) completely different between the two sexes
B) partially homologous, but also have unique regions
C) found only in males
D) unable to line up properly at the metaphase plate
E) completely homologous, but always have different alleles

Question 26

Before they begin meiosis I, sister chromatids ______.

A) are separated during anaphase I
B) have different alleles for the same genes
C) are replicated before meiosis I and II
D) are replicated before meiosis II
E) have identical DNA sequences

Question 27

During what stage of meiosis does the nuclear membrane begin to reform around a haploid number of chromosomes composed of one chromatid each?

A) telophase I
B) interkinesis
C) anaphase I
D) telophase II
E) prophase II

Question 28

Meiosis produces ____.

A) four haploid cells
B) two diploid cells
C) two diploid cells and two haploid cells
D) four diploid cells
E) one haploid and three diploid cells

Question 29

Which structure holds homologous chromosomes tightly together and supports them as they undergo recombination?

A) kinetochore
B) centromere
C) microtubules
D) spermatozoa
E) synaptonemal complex

Question 30

In a frog in which the diploid number of chromosomes per cell is 24, what is the total number of chromatids present during prophase I?

A) 4
B) 6
C) 12
D) 24
E) 48

Question 31

What is the difference between sister chromatids before and after anaphase II?

A) Before anaphase II, the sister chromatids are separate; after anaphase II, the sister chromatids join and form a chromosome.
B) Before anaphase II, the sister chromatids form a single chromosome; after anaphase II, each sister chromatid is an individual chromosome.
C) Before anaphase II, each sister chromatid is an individual chromosome; after anaphase II, the sister chromatids form a single chromosome.
D) Before anaphase II, the sister chromatids form a single chromosome; after anaphase II, the sister chromatids become homologous chromosomes.
E) There is no difference; they are still together as a single chromosome.

Question 32

A zygote is formed ____.

A) after a fertilized egg undergoes mitotic divisions to mature
B) by the fusion of male and female somatic cells
C) by the fusion of an egg cell and a sperm cell and the resultant fusion of their nuclei
D) directly by meiosis in fungi
E) by the mitotic divisions of spores in plants

Question 33

In meiosis, sister chromatids ____.

A) separate before DNA replication
B) separate before crossing-over
C) separate during anaphase I
D) separate during anaphase II
E) never separate; sister chromatids do not separate in meiosis

Question 34

If both chromatids of a sister-chromatid pair are found in one daughter cell, what most likely occurred?

A) improper replication of DNA
B) failure of maternal and paternal chromosomes to separate
C) nondisjunction during meiosis I
D) nondisjunction during meiosis II
E) an error during crossing-over

Question 35

During telophase I, ____.

A) chromosomes condense
B) chromosomes align along the equatorial plane of the cell
C) nuclear envelopes form in some species, but not in others
D) homologous chromosomes separate
E) tetrads form

Question 36

Which stage of meiosis is characterized by DNA condensation into compact chromosomes?

A) prometaphase II
B) anaphase I
C) prophase II
D) prometaphase I
E) metaphase I

Question 37

Which of the following occurs during interkinesis?

A) The single spindle of the first meiotic division disassembles.
B) Two new meiotic spindles reassemble for the second meiotic division.
C) Two spindles from the first meiotic division disassemble.
D) DNA is replicated.
E) Both answer a and answer b are correct.

Question 38

Which statement describes a difference between human male and female somatic cells?

A) Male somatic cells contain only paternal chromosomes; female somatic cells contain only maternal chromosomes.
B) Male somatic cells contain 46 chromosomes; female somatic cells contain 44 chromosomes.
C) Male somatic cells contain 44 chromosomes; female somatic cells contain 46 chromosomes.
D) Male somatic cells contain two X chromosomes; female somatic cells contain an X chromosome and a Y chromosome.
E) Male somatic cells contain 22 pairs of homologous chromosomes; female somatic cells contain 23 pairs of homologous chromosomes.

Question 39

Which statement correctly describes the X and/or Y chromosomes?

A) The X and Y chromosomes are completely homologous.
B) The Y chromosome determines the sex of the individual.
C) The Y chromosome is larger than the X chromosome.
D) The Y chromosome is found in both males and females.
E) The X chromosome only comes from the father.

Question 40

In a frog in which the diploid number of chromosomes per cell is 24, what is the total number of chromatids present per cell in prophase II after the first division and cytokinesis?

A) 0
B) 6
C) 12
D) 24
E) 48

Question 41

Which pattern of diploid and haploid phases reflects the life cycle in animals?

A) alternation between haploid and diploid generations
B) two haploid generations followed by a diploid generation
C) one haploid generation followed by two diploid generations
D) a single generation that limits the haploid state to gametes, while the rest of the organism is diploid
E) a single generation that limits the diploid state to gametes, while the rest of the organism is haploid

Question 42

When two pairs of homologous chromosomes join for crossing-over, the complex is called a ____.

A) kinetochore
B) centromere
C) sister chromatid
D) tetrad
E) chiasmata

Question 43

Assuming a single cross-over event with respect to one homologous pair of chromosomes, the completion of meiosis produces ____.

A) three daughter cells with parental chromosomes and one daughter cell with a recombinant chromosome
B) four daughter cells with recombinant chromosomes
C) two daughter cells with parental chromosomes and two daughter cells with recombinant chromosomes
D) one daughter cell with parental chromosomes and one cell with recombinant chromosomes
E) two daughter cells, each with recombinant chromosomes

Question 44

Chiasmata form during which phase of meiosis?

A) prophase I
B) metaphase I
C) telophase I
D) prophase II
E) metaphase II

Question 45

Crossing-over during meiosis ____.

A) holds homologous pairs of chromosomes together
B) produces chromosomes consisting of two identical sister chromatids
C) produces daughter nuclei with too much or too little genetic material
D) creates chromosomes containing both paternal and maternal genes
E) ensures that the developing zygote receives cytoplasm from one of the parents

Question 46

Which pattern of diploid and haploid phases reflects the life cycle in some fungi and algae, but not plants or animals?

A) alternation between haploid and diploid generations
B) two haploid generations followed by a diploid generation
C) one haploid generation followed by two diploid generations
D) a life cycle that limits the diploid state to a single cell produced by fertilization
E) a life cycle that limits the haploid state to a single cell that is immediately fertilized

Question 47

The process of fertilization joins male and female gametes ____.

A) randomly
B) that contain a greater number of paternal chromosomes
C) that contain a greater number of maternal chromosomes
D) with the fewest mutations
E) with the best adaptive traits

Question 48

In plants, the gametes produced by a particular gametophyte are ____.

A) always identical because they result from meiosis
B) always identical because they result from mitosis
C) sometimes identical because they result from meiosis
D) sometimes identical because they result from mitosis
E) never identical because they result from meiosis

Question 49

Crossing-over ____.

A) only takes place towards the middle of chromatids
B) can only occur once for each non-sister chromatid
C) can only occur once for each homologous chromosome pair
D) only takes place between sister chromatids
E) can occur at multiple sites in each set of paired chromosomes

Question 50

Following the completion of meiosis in animals, males produce ____ sperm cell(s) and females produce ____ egg(s).

A) 4 diploid; 1 diploid
B) 4 haploid; 1 haploid
C) 2 diploid; 4 haploid
D) 4 haploid; 2 diploid
E) 4 haploid; 3 haploid

Question 51

By itself, independent assortment of chromosomes increases the likelihood that individual daughter cells have ____.

A) some paternal chromosomes and some maternal chromosomes
B) only paternal chromosomes
C) only maternal chromosomes
D) chromosomes containing genes from both paternal and maternal chromosomes
E) different numbers of chromosomes

Question 52

Which statement describes a similarity between the diploid and haploid phases of plant life?

A) Both end in fertilization.
B) Both are multicellular.
C) Both are immediately followed by meiosis.
D) Both contain sporophytes.
E) Both contain spores.

Question 53

Recombination at the synaptonemal complex always results in ____.

A) two changed and two unchanged chromatids
B) four unchanged chromatids
C) four changed chromatids
D) a random number of changed vs. unchanged chromatids
E) one unchanged and three changed chromatids

Question 54

The manner in which chromosomes align themselves along the metaphase plate is completely random. This quality makes ____ possible.

A) metaphase I
B) synapsis
C) meiosis
D) fertilization
E) independent assortment

Question 55

An unknown organism from an alien planet is observed and found to have a diploid state in every other generation that results from fertilization. The haploid state is able to grow into a gametophyte-like structure. This alien organism most closely mimics the life cycle strategy of which of the following earth organisms?

A) humpback whale
B) chimpanzee
C) algae
D) bacteria
E) all plants and some fungi

Question 56

Two genes ( A and B ) are located on each of two pairs of homologous chromosomes. In a tetrad, one sister chromatid contains alleles ab , while the other sister chromatid contains alleles AB (upper and lower case indicate different alleles of the same gene). Which genetic combinations are possible in the four gametes that are produced from a single chiasma between these chromosome pairs?

A) Ab , AB , ab , aB
B) Ab , Ab , aB , aB
C) Aa , Bb , ab , Ab
D) Ab , Ab , AB , AB
E) AB , AB , ab , ab

Question 57

Which pattern of diploid and haploid phases reflects the life cycle in plants?

A) alternation between haploid and diploid generations
B) two haploid generations followed by a diploid generation
C) one haploid generation followed by two diploid generations
D) a single generation that limits the haploid state to gametes, while the rest of the organism is diploid
E) a single generation that limits the diploid state to gametes, while the rest of the organism is haploid

Question 58

Identical twins can result from ____.

A) the fusion of two sets of identical gametes
B) a division of a zygote into two separate cells that develop into two separate embryos
C) the fusion of two paternal gametes with a single maternal gamete that then divides
D) a lack of chromosomal separation during meiosis resulting in gametes that are diploid
E) a mechanism that is not understood

Question 59

What is the immediate product of meiosis in plants?

A) diploids
B) gametes
C) spores
D) sporophytes
E) somatic cells

Question 60

If a species has 42 pairs of chromosomes, how many maternal and paternal chromosome combinations are possible during independent assortment?

A) 42²
B) 2⁴²
C) 2²¹
D) 21²
E) 84²

Question 63

Which statement describes the production of offspring by wingless female aphids?

A) Wingless female aphids can produce clones of female offspring by laying eggs.
B) When the amount of food available in the environment increases, the number of male offspring increases.
C) Wingless female aphids only produce female clones, and these clones are made without the mother laying eggs.
D) Different proportions of winged male, non-egg-laying female, and egg-laying female offspring are produced based on the temperature and amount of daylight.
E) Environmental conditions do not affect the sexuality of wingless female aphid offspring; sexuality is only determined genetically.

Question 65

At what stage of meiosis do sister chromatids become separate chromosomes?

A) anaphase I
B) metaphase I
C) anaphase II
D) telophase II
E) both prophase I and anaphase II

Question 66

Describe the meiotic events that generate genetic diversity in gametes.

Question 67

If an organism has the same life strategy as a maple tree, the synaptonemal complex will be observed ____.

A) only in alternating generations
B) in each generation
C) only in a unicellular haploid phase
D) only in a multicellular haploid phase
E) only in gametophytes

Question 68

Compare the events of meiosis I and II in the production of gametes.

Question 69

Genetic variability in meiosis results from ____.

A) recombination of homologous chromosomes only
B) independent assortment of chromosomes only
C) random joining of male and female gametes only
D) recombination between sister chromatids and homologous chromosomes
E) recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes

Question 70

After the first meiotic division, the two daughter cells ____.

A) are identical to each other
B) replicate their DNA before dividing again
C) contain unequal chromosome numbers
D) have half the diploid number of chromosomes
E) always contain equal numbers of paternal and maternal chromosomes

Question 71

List and briefly explain the three ways in which genetic variability is increased during meiosis.

Question 72

Explain the purpose of meiosis.

Question 73

In some organisms, crossing-over does not occur, and the homologous chromosomes are held together via some other mechanism. Even though crossing-over leads to genetic diversity, the absence of crossing-over in these organisms does not prevent the production of diverse gametes. Why is this?

Question 74

In plants and some fungi, individuals that form the diploid generation are called ____.

A) spores
B) sporophytes
C) gametophytes
D) spermatozoa
E) ova

Question 75

How do the haploid and diploid phases of the plant life cycle differ from those of the animal life cycle?

A) In plants, the diploid phase dominates the life cycle, while in animals the haploid phase dominates the life cycle.
B) In plants, mitosis occurs only during the haploid phase, while in animals mitosis occurs only during the diploid phase.
C) In plants, mitosis occurs only during the diploid phase, while in animals mitosis occurs only during the haploid phase.
D) In plants, mitosis occurs during both the haploid and diploid phases, while in animals mitosis occurs only during the diploid phase.
E) In plants, meiosis occurs during the haploid phase, while in animals meiosis occurs during the diploid phase.

Question 76

Which statement describes a similarity between meiosis and mitosis?

A) Both halve the chromosome number of the parent cell.
B) Both produce 4 daughter cells.
C) Both produce genetically identical daughter cells.
D) Both create genetically different daughter cells.
E) DNA is replicated only once in both processes.

Question 77

Which statement most accurately describes plant gametes?

A) Gametophytes produced by mitotic divisions of spores can mature into gametes.
B) Gametes are formed directly from meiosis.
C) Haploid spores produced by meiosis are mature gametes.
D) Gametophytes produced directly from meiosis are mature gametes.
E) Sporophytes undergo meiosis to produce mature gametes called spores.

Question 78

What is the main difference between the haploid and diploid phases of animal and plant life cycles?

Question 79

Describe the life cycles of animals, plants/some fungi, and other fungi/algae with respect to the amount of time each type of organism spends in their haploid and diploid phases. Also, indicate whether those haploid and diploid phases are unicellular or multicellular.

Question 80

How is sexual reproduction facilitated in flowering plants?

A) Pollen reaches the ovule by traveling through the flower petal.
B) The male gametophyte is found in the flower, while the female gametophyte is released as pollen.
C) The female gametophyte is found in the flower, while the male gametophyte is released as pollen.
D) Pollen is only able to fertilize plants of different species to ensure genetic diversity.
E) The ovule is carried by birds to other plants for reproduction to occur with the male gametophyte.