Bio 181 Chapter 13

Which of the following processes occurs when homologous chromosomes cross over in meiosis I?

Corresponding segments of non-sister chromatids are exchanged

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

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome would be expected to produce which of the following types of eggs after meiosis?

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

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?

Genes of privet shrub chromosomes are significantly different than those in humans.

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

Homologous chromosomes of a pair are separated from each other.

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. A bar graph shows DNA content (n) from 0 to 8. Three samples have the following amounts of DNA: Sample I, 2 units; sample II, 4 units, sample III, 1 unit. Which sample of DNA might represent a zygote?

I

Refer to the drawings in the figure below of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis, and answer the following question(s). Which diagram represents anaphase I of meiosis?

I

Refer to the life cycles illustrated in the figure below to answer the following questions. Which of the life cycles is typical for animals?

I only

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. A bar graph shows DNA content (n) from 0 to 8. Three samples have the following amounts of DNA: Sample I, 2 units; sample II, 4 units, sample III, 1 unit. Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior to meiosis?

II

For the following questions, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Homologous chromosomes are aligned at the equator of the spindle.

II

Refer to the life cycles illustrated in the figure below to answer the following questions. Which of the life cycles is typical for most fungi and some protists?

II only

Refer to the life cycles illustrated in the figure below to answer the following questions. Which of the life cycles is typical for plants and some algae?

III only

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?

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 is correct in comparing sexual and asexual reproduction?

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

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

It carries genes that determine an individual's biological sex

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?

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.

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

Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction.

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 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.

How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I?

The cells have half the number of chromosomes and one-fourth the amount of DNA.

Imagine 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?

The sexually reproducing species is likely to thrive

Refer to the life cycles illustrated in the figure below to answer the following questions. 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?

The sporophyte's chromosome number per cell is ten and the gametophyte's is five.

Refer to the drawings in the figure below of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis, and answer the following question(s). Which diagram represents anaphase II of meiosis?

V

For the following questions, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II Centromeres of sister chromatids disjoin and chromatids separate.

VII

A human cell containing 22 autosomes and a Y chromosome is

a sperm

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

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?

by fertilization

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?

crossing over and random fertilization

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

during both mitosis and meiosis II

Which of the following processes occurs in a plant's sexual life cycle?

gametophytes produce gametes by mitosis

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

in meiosis I only

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?

length, centromere position, staining pattern, and traits coded for by their genes

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

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?

metaphase

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

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, which of the following combinations of genes and chromosomes will her eggs have?

one chromosome 12 with one blue gene and one chromosome 19 with one long gene

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. Chromosome 12 is shown as blue or orange; Chromosome 19 as either long or short. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, which of the following combinations of genes will her eggs have?

one half blue short and one half orange short gene eggs

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred?

prophase I

Which of the following processes facilitates the fastest way for organisms 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 occurs in meiosis but not in mitosis?

synapsis of chromosomes

Which of the following statements defines a 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

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

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

x

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 can send out underground stems for asexual reproduction. 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

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?

63 chromosomes in 21 sets of 3

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

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