Chapter 10 Meiosis and Sexual Reproduction

If a sperm cell contains 8 chromosomes, it comes from an animal that has ______ chromosomes.

16

Which of the following is/are true about sexual reproduction?

E. All of the choices are true.

Which of the following is/are true about sexual reproduction? A. At the cellular level is the opposite of reproduction since it involves two cells fusing to become one. B. It requires the development of organs such as the uterus, which are of no immediate survival advantage to the individual but are advantageous to the species. C. It regularly produces a wider array of adaptations to the external environment in a shorter period of time. D. It regularly produces a wider array of adaptations to the internal environment (disease agents, parasites) in a shorter period of time. E. All of the choices are true.

E. All of the choices are true.

Which is NOT true about daughter cells of mitosis or meiosis?

E. In meiosis, the daughter cells are genetically identical.

Which is NOT true about daughter cells of mitosis or meiosis? A. In meiosis, daughter cells are haploid. B. In meiosis, there are four daughter cells. C. In mitosis, there are two daughter cells. D. In mitosis, the daughter cells are genetically identical. E. In meiosis, the daughter cells are genetically identical.

E. In meiosis, the daughter cells are genetically identical.

Why do polar bodies form?

E. They allow a reduction in chromosomes while preserving most of the cytoplasm for one egg.

During which stage of meiosis are the bivalents arranged along the equator?

E. metaphase I

During which stage of meiosis does crossing-over occur?

E. prophase I of meiosis I

A change in the chromosome number resulting from nondisjunction is called euploidy. True False

False

A lattice holds the members of a bivalent together in such a way that the RNA of the non-sister chromatids is aligned. True False

False

Only one of the four daughter cells becomes a functional gamete in spermatogenesis. True False

False

Oogenesis always involves an equal division of cell contents in the formation of an egg and polar bodies. True False

False

Primary nondisjunction occurs during meiosis II when the sister chromatids fail to separate and both daughter chromosomes go in the same gamete. True False

False

The correct number of chromosomes in a species is known as aneuploidy True False

False

What is the importance of crossing-over?

It increases the likelihood that daughter cells contain different genetic material.

It could be said that males are able to provide gametes with more genetic diversity than females for reproduction. One main reason would be:

Spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg and three structures that contain genetic information that is lost when they disintegrate.

Aneuploidy is a change in the number of chromosomes resulting from nondisjunction during meiosis. True False

True

Extra copies of sex chromosomes are more easily tolerated in humans than extra copies of autosomes. True False

True

It is estimated that an average of two or three cross-overs occur per human chromosome. True False

True

Jacobs Syndrome, XYY, results from nondisjunction during spermatogenesis. True False

True

Monosomy occurs when an individual has only one of a particular type of chromosome. Refer To; 10-35 True False

True

Sex chromosome aneuploids are better tolerated and have a better chance of producing survivors. True False

True

During which stage of meiosis does crossing-over occur?

prophase I of meiosis I

Sources of genetic variation in a sexually reproducing population include(s) which of the following?

All of the choices are sources of genetic variation.

If the diploid number of chromosomes for an organism is 52, what will the haploid number of chromosomes be?

B. 26

Which of the following is NOT a difference between anaphase I and anaphase II?

B. Anaphase I occurs in a haploid cell while anaphase II occurs in a diploid cell.

Which of the following statements is correct about the chromosomal position during mitosis and meiosis?

B. During metaphase of mitosis the duplicated chromosomes are at the metaphase plate while during metaphase I of meiosis the bivalents are present at the metaphase plate

What is the importance of crossing-over?

B. It increases the likelihood that daughter cells contain different genetic material.

There is a species of desert lizard where only females are known to exist-there are no males known. It is nevertheless necessary for two females to court and for one to assume the posture of a male to stimulate the female to produce eggs. No fertilization can occur, and the eggs develop into female lizards. What is the probable evolutionary mechanism for this occurring?

B. The desert is relatively uniform and there is little advantage to maintaining variation, but the animal has not been able to completely evolve away from its heritage of sexual reproduction.

If a cell contains 12 chromosomes at the end of meiosis I, how many chromosomes will the daughter cells contain at the end of meiosis II?

C. 12

In the genus Lacerta are species of lizards that are female and do not mate. They undergo "endomitosis" where one extra chromosome replication results in a tetraploid cell before meiosis begins. Normal female 2n offspring result without fertilization. What change(s) from regular meiosis (in preparation for fertilization) would be required to produce this system?

C. Cytokinesis does not follow "endomitosis" that results in a tetraploid cell.

Which statement is NOT true about homologues in meiosis I?

C. Each homologue's centromere splits to form two chromosomes.

Interkinesis is different from interphase in which way? A. Interkinesis occurs after a cell finishes a nuclear division. B. Interkinesis is the stage that precedes a prophase stage. C. Interphase involves DNA replication and interkinesis does not. D. Interkinesis can be variable in length.

C. Interphase involves DNA replication and interkinesis does not.

It could be said that males are able to provide gametes with more genetic diversity than females for reproduction. One main reason would be:

C. Spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg and three structures that contain genetic information that is lost when they disintegrate.

The polar body is

C. a nonfunctional cell rudiment formed at the same time as an egg cell.

The polar body is A. another name for an egg cell. B. a precursor cell that becomes an egg cell. C. a nonfunctional cell rudiment formed at the same time as an egg cell. D. the cell produced when fertilization occurs.

C. a nonfunctional cell rudiment formed at the same time as an egg cell.

During which stage of meiosis does the homologue separation occur?

C. anaphase I

At which stage of meiosis is each chromosome composed of a single chromatid?

C. anaphase II

Before the time of Gregor Mendel and genetics, sexual reproduction was thought to produce a blending or equal mixing of the parents' traits. Today we know that

C. offspring inherit essentially 50% of their genes from each parent, but two sibling offspring may share with each other from zero to 23 chromosomes in common from each parent, and further variation may occur due to crossing-over.

Why do polar bodies form? A. They nurse the egg as it leaves the follicle. B. This is extra chromosomal material representing the X chromosome in each female cell. C. They orient the sperm toward the egg. D. They allow a reduction in chromosomes while preserving all the food for one egg. E. They orient the egg for penetration by the sperm.

D. They allow a reduction in chromosomes while preserving all the food for one egg.

To what does the term chiasma refer?

D. a structure that holds together homologues during crossing-over

All of the following are true concerning Down Syndrome EXCEPT

D. chances of a woman having a child with Down Syndrome decreases with her age

All of the following are true concerning Down Syndrome EXCEPT A. it is caused by autosomal trisomy 21 B. in 23% of cases, the sperm contributes the extra chromosome C. it is the most common trisomy in humans D. chances of a woman having a child with Down Syndrome decreases with her age

D. chances of a woman having a child with Down Syndrome decreases with her age

The overall function of meiosis includes all of the following EXCEPT

D. growth of the overall individual.

Where in the human male does spermatogenesis occur? A. ovaries B. prostate gland C. epididymus D. testes

D. testes

Which does NOT occur in meiosis?

D. two daughter cells at completion

Another name for a tetrad is a/an

bivalent.

Which of the following steps would NOT lead to variation of genetic material?

crossing over of sister chromatids

During which stage of meiosis are the bivalents arranged along the equator?

metaphase I

Sources of genetic variation in a sexually reproducing population include(s) which of the following?

D. All of the choices are sources of genetic variation.

During ___________ the homologous chromosome pairs separate in a random fashion leading to genetic diversity among the offspring.

A. independent assortment

During which stage of meiosis does crossing-over occur?

A. prophase I of meiosis I

Which does NOT occur in meiosis?

A. two daughter cells at completion

Which does NOT occur in meiosis? A. two daughter cells at completion B. four daughter cells at completion C. two nuclear divisions D. formation of bivalents

A. two daughter cells at completion

The cell formed through fertilization of an egg by a sperm is called a/an

A. zygote.

Which statement is NOT true about homologues in meiosis I?

D. Each homologue's centromere splits to form two chromosomes.

If a cell contains 12 chromosomes at the end of meiosis I, how many chromosomes will the daughter cells contain at the end of meiosis II?

A. 12

Which is NOT true about daughter cells of mitosis or meiosis?

A. In meiosis, the daughter cells are genetically identical.

Homologous chromosomes are similar in all of these characteristics EXCEPT:

A. carry the same alleles for all traits.

There is a species of desert lizard where only females are known to exist-there are no males known. It is nevertheless necessary for two females to court and for one to assume the posture of a male to stimulate the female to produce eggs. No fertilization can occur, and the eggs develop into female lizards. What is the probable evolutionary mechanism for this occurring? A. The species is probably going extinct. B. The desert is relatively uniform and there is little advantage to maintaining variation, but the animal has not been able to completely evolve away from its heritage of sexual reproduction. C. This switch in mating behavior is the direct physical reflection of crossing-over. D. This is probably an asexual organism attempting to mimic sexual reproduction.

B. The desert is relatively uniform and there is little advantage to maintaining variation, but the animal has not been able to completely evolve away from its heritage of sexual reproduction.

To what does the term chiasma refer?

B. a structure that holds together homologues

During which stage of meiosis does homologue separation occur?

B. anaphase I

Another name for a tetrad is a/an

B. bivalent.

Homologous chromosomes are similar in all of these characteristics EXCEPT:

B. carry the same alleles for all traits.

Which of the following steps would NOT lead to variation of genetic material?

B. crossing over of sister chromatids

The picture at right depicts which of the following changes in chromosome structure.

B. duplication

The picture at right depicts which of the following changes in chromosome structure. A. deletion B. duplication C. translocation D. aneuploidy

B. duplication

In human females, when is meiosis II completed?

B. immediately after the sperm penetration of the secondary oocyte

In human females, when is meiosis II completed? A. at ovulation B. immediately after the sperm penetration of the secondary oocyte C. immediately after the sperm penetrates the primary oocyte D. None of the choices are correct.

B. immediately after the sperm penetration of the secondary oocyte

Meiosis occurs during all of the following EXCEPT

B. pangenesis.

Species X reproduces asexually by fission and species Y reproduces sexually. Consider that all other relevant characteristics are similar between these species. When the environment changes, then

B. species Y should have a better chance of surviving than species X.

Species X reproduces asexually by fission and species Y reproduces sexually. Consider that all other relevant characteristics are similar between these species. When the environment gradually changes, then A. species X and Y will have an equal chance of surviving. B. species Y should have a better chance of surviving than species X. C. species X should have a better chance of surviving than species Y. D. neither species should have an advantage in surviving since organisms often become extinct when the environment changes.

B. species Y should have a better chance of surviving than species X.

Where in the human male does spermatogenesis occur?

B. testes

Before the time of Gregor Mendel and genetics, sexual reproduction was thought to produce a blending or equal mixing of the parents' traits. Today we know that A. offspring will be identical to one another and demonstrate traits exactly halfway between the parents' traits. B. offspring can vary from receiving over 99% of one parent's genes to receiving over 99% of the other parent's genes. C. offspring inherit essentially 50% of their genes from each parent, but two sibling offspring may share with each other from zero to 23 chromosomes in common from each parent, and further variation may occur due to crossing-over. D. offspring inherit copies of the same 23 pair of chromosomes from each of their parents but the rate of crossing-over makes them very dissimilar. E. there is one chance in 23 of getting identical sets of chromosomes from one parent, times two because there are two parents; therefore, two siblings out of every 46 are really identical except for crossing-over.

C. offspring inherit essentially 50% of their genes from each parent, but two sibling offspring may share with each other from zero to 23 chromosomes in common from each parent, and further variation may occur due to crossing-over.

Meiosis occurs during all of the following EXCEPT A. gametogenesis. B. oogenesis. C. pangenesis. D. spermatogenesis.

C. pangenesis.

The picture at right depicts which of the following changes in chromosome structure.

C. translocation

The picture at right depicts which of the following changes in chromosome structure. A. deletion B. duplication C. translocation D. aneuploidy

C. translocation

The cell formed through fertilization of an egg by a sperm is called a/an

C. zygote.

If a sperm cell contains 8 chromosomes, it comes from an animal that has ______ chromosomes.

D. 16