Topic 10. Meiosis and Sexual Life Cycles

A human cell containing 22 autosomes and a Y chromosome is ________.

A sperm

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?

About 8 million

Which of the following results when homologous chromosomes cross over in meiosis?

Corresponding segments of non-sister chromatids are exchanged.

Which of the following processes occur during meiosis but not mitosis?

Diploid cells form haploid cells.

Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I?

Each chromosome consists of two sister chromatids joined by a centromere.

Which of the following statements is true of a species that has a chromosome number of 2n = 16? NOT The species has 16 sets of chromosomes per cell.

Each diploid cell has eight homologous pairs of chromosomes. (?)

A (hypothetical) diploid organism has different genes that control wing color and wing length. A female of this species has a paternal chromosome set containing one orange-wing allele and one long-wing allele and a maternal set containing one blue-wing allele and one short-wing allele. Which of the following types of eggs would she be expected to produce after meiosis?

Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.

Which of the following events happens at the conclusion of meiosis I?

Homologous chromosomes of a pair are separated from each other.

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents anaphase I of meiosis?

I

Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is in telophase I?

I

For the following question, match the key event of meiosis with the stages listed below. Homologous chromosomes are aligned at the middle of the spindle.

II

Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is entering mitosis?

II

Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that is in metaphase I?

II

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents prophase of mitosis?

III

Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that has completed meiosis?

III

Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question. Which sample is consistent with a cell that has completed mitosis?

III

For the following question, match the key event of meiosis with the stages listed below. Haploid cells form containing joined sister chromatids.

IV

Which of the following explanations correctly describes a reproductive approach?

In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

Which of the following statements about reproduction is correct?

In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.

Which of the following statements about the human X chromosomes is correct?

It carries genes that influence an individual's biological sex.

A cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II. Which of the following statements describes its genetic contents?

It has half the amount of DNA as the cell that began meiosis.

Which of the following statements correctly describes a karyotype?

It is an organized image of a cell's chromosomes

A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?

It produces gametes with 23 chromosomes.

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?

Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism?

Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I.

A triploid cell contains three sets of homologous chromosomes. Which of the following describes the chromosomes in a triploid cell where n = 6?

The cell has 18 total chromosomes in 6 sets.

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?

The cells are haploid, and the chromosomes are each composed of two chromatids.

The somatic cells of a particular plant 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?

The genes on this plant's largest chromosome are significantly different than those on the largest human chromosome.

Which of the following statements best describes homologous chromosomes?

They carry information for the same traits.

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

Two

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents anaphase II of meiosis?

V

Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question(s). Which diagram represents metaphase of mitosis?

VI

For the following question, match the key event of meiosis with the stages listed below. Cohesins at centromeres of sister chromatids breakdown.

VII

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of a single cell at metaphase of meiosis II will be ________.

X

Which of the following characteristics are part of the sexual life cycle of most fungi but are not part of the sexual life cycles of plants or animals?

a unicellular haploid stage

Which of the following processes will most likely produce a human zygote with 45 chromosomes?

an error during anaphase II while the sperm was produced

During which of the following phases of meiosis do homologous chromosomes separate?

anaphase I

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?

anaphase II

During which of the following processes do sister chromatids separate from each other?

during both mitosis and meiosis II

Many diploid organisms produce haploid gametes for reproduction. Which of the following best describes how the diploid number of chromosomes is restored in the offspring of these organisms?

fertilization combines chromosomes from each parent into resulting zygote

Which of the following processes best describes the mechanism of gamete production in plants?

gametophytes produce gametes by mitosis

During which of the following processes does independent assortment of chromosomes occur?

in meiosis I only

Which of the following pairs of processes make the greatest contribution to genetic diversity between generations of a diploid insect?

independent assortment and random fertilization

Crossing over of chromosomes normally takes place during which of the following processes?

meiosis I

The two homologs of a pair move toward opposite poles of dividing cell during

meiosis I

The two homologs of a pair move toward opposite poles of dividing cell during ________.

meiosis I

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?

metaphase I of meiosis

Asexual reproduction occurs during which of the following processes?

mitosis

Which of the following processes has just occurred when chiasmata can first be viewed under a microscope?

prophase 1

Which of the following processes facilitates the fastest way for animal species to adapt to a changing environment?

sexual reproduction

Meiosis II is similar to mitosis in that ________.

sister chromatids separate during anaphase

Which of the following processes occur during meiosis but not mitosis?

synapsis of chromosomes

Which of the following processes occurs in meiosis but not in mitosis?

synapsis of chromosomes

Which of the following phrases defines the term genome?

the complete set of an organism's genes and other DNA sequences

Independent assortment of chromosomes is a result of which of the following processes?

the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

A (hypothetical) diploid organism has different genes that control wing length and wing color. A female of this species with short blue-colored wings has a chromosome pair with two short-wing alleles and a second chromosome pair with one blue-wing allele and one orange-wing allele. The eggs from this individual will have which of the following combinations of alleles?

1/2 of the eggs will have alleles for short blue-colored wings and ½ will have alleles for short orange-colored wings

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 ________.

2x

Quaking aspen trees usually reproduce by extending underground stems that then push aboveground and grow into trees. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems?

38

The figure represents the nucleus of an animal cell about to enter mitosis. How many chromosomes are present in the diagram?

8

Which of the following statements describes an accurate example of alternation of generations?

A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).