MasteringBio Week 10

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 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

Normal gametes produced from one meiotic event

each have the same chromosome number

Heritable variation is required for which of the following?

evolution

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

Meiosis II is similar to mitosis in that

sister chromatids separate during anaphase.

In alternation of generations, what is the diploid stage of a plant that follows fertilization called?

sporophyte

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

synapsis of chromosomes

If the DNA content of a diploid cell is xx in the G1 phase of the cell cycle and 2x at metaphase of meiosis I, then the DNA content of the same cell at metaphase of meiosis II will be

x

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

2

If the DNADNA content of a diploid cell in the G1G1 phase of the cell cycle is xx, then the DNADNA content of the same cell at metaphase of meiosis I will be

2x

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

4

What number and types of chromosomes are found in a human somatic cell?

44 autosomes & 2 sex chromosomes

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

Each diploid cell has eight homologous pairs of chromosomes.

Which of the following statements correctly describes how sister chromatids and homologous chromosomes differ from each other?

Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication. One homologous chromosome comes from the father, and the other comes from the mother. Sister chromatids are identical copies of each other.

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. Which diagram represents anaphase I of meiosis?

I

For the following question, match the key event of meiosis with the stages listed below. I.Prophase IV.Prophase IIII.Metaphase IVI.Metaphase IIIII.Anaphase IVII.Anaphase IIIV.Telophase IVIII.Telophase II Homologous chromosomes are aligned at the middle of the spindle.

II

Which diagram represents prophase of mitosis?

III

How does natural selection apply to sexual reproduction as opposed to asexual reproduction?

Sexual reproduction results in new gene combinations, some of which will have increased reproductive fitness

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.

Which of the following statements best describes homologous chromosomes?

They carry information for the same traits.

Look at the cell in the figure. Based on this figure, which of the following statements is true?

This cell is diploid. This cell contains two copies of each chromosome, one from the male parent and the other from the female parent, making it diploid.

For the following question, match the key event of meiosis with the stages listed below. I.Prophase IV.Prophase IIII.Metaphase IVI.Metaphase IIIII.Anaphase IVII.Anaphase IIIV.Telophase IVIII.Telophase II Cohesins at centromeres of sister chromatids breakdown.

VII

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

Asexual reproduction __________.

produces offspring genetically identical to the parent

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

prophase I

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

In a typical animal, mitosis produces _________, while meiosis produces____________.

two diploid daughter cells, four haploid daughter cells in mitosis, a cell that has doubled its genetic material divides to produce two diploid daughter cells. In meiosis, a cell that has doubled its genetic material undergoes two rounds of division, producing four haploid daughter cells.

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 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

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 processes occurs in meiosis but not in mitosis?

Meiosis I

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.

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.

What is the best evidence telling you whether this cell is diploid or haploid?

The cell is diploid because it contains two sets of chromosomes

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.

For what purpose(s) might a karyotype be prepared?

The first three answers are correct.

The Cavendish banana, the world's most popular fruit, is currently threatened by extinction due to a fungus. This banana variety is "triploid" (3n3n, with three sets of chromosomes) and can only reproduce through cloning by cultivators. Given what you know about meiosis, choose how the banana's triploid number accounts for its inability to form normal gametes.

With three sets of chromosomes, there is no way for the sets to be separated equally to gametes during meiosis, and so seeds cannot form.

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

independent assortment and random fertilization

In a human karyotype, chromosomes are arranged in 23 pairs. If one of the autosomal pairs is examined, which of the following characteristics will the two chromosomes of the pair have in common?

loci and staining pattern

Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?

meiosis

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 a dividing cell during

meiosis I

Which of the following phrases defines the term genome?

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

Which of the following answers describes the phenomenon of crossing over in meiosis?

the exchange of homologous portions of nonsister chromatids