Question 1

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

Accepted Answer

A) crossing-over in prophase I of meiosis 
B) independent assortment in metaphase I of meiosis 
C) fertilization 
D) All of the choices are sources of genetic variation. 
E) None of the choices are sources of genetic variation. 
A) crossing-over in prophase I of meiosis 
B) independent assortment in metaphase I of meiosis 
C) fertilization 
D) All of the choices are sources of genetic variation. 
E) None of the choices are sources of genetic variation. D

Question 2

Some plants are tetraploid (4n).How might such a plant arise?

Accepted Answer

Tetraploidy could result from a 2n zygote not dividing after replicating its chromosomes,thereby becoming 4n.All cells formed thereafter,by normal mitotic divisions,will have four sets of chromosomes.

Question 3

Sexual reproduction brings about genetic variation within a species.How does sexual reproduction contribute to variation? Why is genetic variation so important to the survival of a species? Support your answer with an example.

Accepted Answer

Answers may vary.Genetic recombination,independent assortment of homologous chromosomes,and the union of egg and sperm in sexual reproduction create offspring with a different set of alleles than their parents.These processes brings about great genetic variability,which is extremely important to the survival of a species in the ever-changing environments of the earth.With variation,a species will exhibit a variety of traits that may react differently to different environments.A limited number of traits may allow the organisms to fit very nicely into their present environment.In time,the environment may change,and these limited traits may no longer allow the species to thrive in this new environment.The presence of other (alternate)traits may allow some offspring to survive and reproduce better than others under the new conditions.An example would be the mutant type of Daphnia water flea,which prefers warmer water than the original type.If the earth's waters warmed with global warming,the mutant would be favored and the original type would not thrive.

Question 4

Which does NOT occur in meiosis?

Accepted Answer

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 
B) four daughter cells at completion 
C) two nuclear divisions 
D) formation of bivalents

Question 5

Characterize the following statements about changes in chromosome number and structure as True or False.
-Monosomy occurs when an individual has only one of a particular type of chromosome.

Accepted Answer

A) True 
 B)False

Question 6

What is the function of polar bodies?

Accepted Answer

A) They nurse the egg as it leaves the follicle. 
B) They orient the sperm toward the egg. 
C) They allow a reduction in chromosomes while preserving most of the cytoplasm for one egg. 
D) They orient the egg for penetration by the sperm. 
A) They nurse the egg as it leaves the follicle. 
B) They orient the sperm toward the egg. 
C) They allow a reduction in chromosomes while preserving most of the cytoplasm for one egg. 
D) They orient the egg for penetration by the sperm.

Question 7

To what does the term chiasma refer?

Accepted Answer

A) the process of fertilization 
B) structures that hold the chromosomes in alignment on the metaphase plate 
C) the process of crossing-over 
D) a structure that holds together homologues during crossing-over 
E) the period between meiosis I and meiosis II 
A) the process of fertilization 
B) structures that hold the chromosomes in alignment on the metaphase plate 
C) the process of crossing-over 
D) a structure that holds together homologues during crossing-over 
E) the period between meiosis I and meiosis II

Question 8

Jacobs syndrome,XYY,results from nondisjunction during spermatogenesis.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is a true statement concerning meiosis in males and females?

Accepted Answer

A) Males provide more genes in sperm than females provide in eggs. 
B) Crossing-over occurs more often in the formation of sperm than in eggs. 
C) Spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg. 
D) Sperm that contain a recombination of genes are usually more successful in fertilizing an egg. 
A) Males provide more genes in sperm than females provide in eggs. 
B) Crossing-over occurs more often in the formation of sperm than in eggs. 
C) Spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg. 
D) Sperm that contain a recombination of genes are usually more successful in fertilizing an egg.

Question 10

Which of the following is not a characteristic of homologous chromosomes?

Accepted Answer

A) They are similar in size. 
B) They carry the same alleles for all traits. 
C) They carry genes for the same traits. 
D) They are similar in shape and location of the centromere. 
A) They are similar in size. 
B) They carry the same alleles for all traits. 
C) They carry genes for the same traits. 
D) They are similar in shape and location of the centromere.

Question 11

Where in the human male does spermatogenesis occur?

Accepted Answer

A) ovaries 
B) prostate gland 
C) epididymus 
D) testes 
E) penis 
A) ovaries 
B) prostate gland 
C) epididymus 
D) testes 
E) penis

Question 12

Identify the chromosomal abnormalities as well as the physical features present in a person suffering from Turner syndrome.

Accepted Answer

An individual who inherits XO will show

Question 13

A lattice holds the members of a bivalent together in such a way that the RNA of the nonsister chromatids is aligned.

Accepted Answer

A) True 
 B)False

Question 14

A primary spermatocyte has 64 chromosomes.After meiosis I,each secondary spermatocyte would have 32 chromosomes.After meiosis II,each spermatid would have 16 chromosomes.

Accepted Answer

A) True 
 B)False

Question 15

During which stage of meiosis does crossing-over occur?

Accepted Answer

A) prophase I of meiosis I 
B) anaphase I of meiosis II 
C) telophase I of meiosis I 
D) prophase II of meiosis II 
E) anaphase II of meiosis I 
A) prophase I of meiosis I 
B) anaphase I of meiosis II 
C) telophase I of meiosis I 
D) prophase II of meiosis II 
E) anaphase II of meiosis I

Question 16

If a sperm cell contains 8 chromosomes,it comes from an animal whose regular body cells have ________ chromosomes.

Accepted Answer

A) 4 
B) 8 
C) 12 
D) 16 
E) 24 
A) 4 
B) 8 
C) 12 
D) 16 
E) 24

Question 17

Which of the following statements is true about the life cycle of animals?

Accepted Answer

A) The gametes are the haploid phase of the animals' life cycle. 
B) The gametes are the diploid phase of the life cycle. 
C) The products of the haploid phase of the life cycle are larger than those of the diploid phase. 
D) Meiosis is not a necessary component of the animal life cycle. 
A) The gametes are the haploid phase of the animals' life cycle. 
B) The gametes are the diploid phase of the life cycle. 
C) The products of the haploid phase of the life cycle are larger than those of the diploid phase. 
D) Meiosis is not a necessary component of the animal life cycle.

Question 18

Which of the following would NOT contribute to genetic variation?

Accepted Answer

A) crossing-over of homologous chromosomes 
B) crossing-over of sister chromatids 
C) the random alignment of the chromosomes during metaphase I 
D) the combination of sperm and egg genes 
A) crossing-over of homologous chromosomes 
B) crossing-over of sister chromatids 
C) the random alignment of the chromosomes during metaphase I 
D) the combination of sperm and egg genes

Question 19

Meiosis occurs during all of the following EXCEPT

Accepted Answer

A) gametogenesis. 
B) oogenesis. 
C) spermatogenesis. 
D) A,B,and C all involve meiosis. 
E) Neither A,B,or C.All of the above involve mitosis. 
A) gametogenesis. 
B) oogenesis. 
C) spermatogenesis. 
D) A,B,and C all involve meiosis. 
E) Neither A,B,or C.All of the above involve mitosis.

Question 20

In human females,when is meiosis II completed?

Accepted Answer

A) at ovulation 
B) immediately after the sperm penetrates the secondary oocyte 
C) immediately after the sperm penetrates the primary oocyte 
D) after the zygote has formed 
A) at ovulation 
B) immediately after the sperm penetrates the secondary oocyte 
C) immediately after the sperm penetrates the primary oocyte 
D) after the zygote has formed

Exam 10: Meiosis and Sexual Reproduction

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

Some plants are tetraploid (4n).How might such a plant arise?

Sexual reproduction brings about genetic variation within a species.How does sexual reproduction contribute to variation? Why is genetic variation so important to the survival of a species? Support your answer with an example.

Which does NOT occur in meiosis?

Characterize the following statements about changes in chromosome number and structure as True or False. -Monosomy occurs when an individual has only one of a particular type of chromosome.

What is the function of polar bodies?

To what does the term chiasma refer?

Jacobs syndrome,XYY,results from nondisjunction during spermatogenesis.

Which of the following is a true statement concerning meiosis in males and females?

Which of the following is not a characteristic of homologous chromosomes?

Where in the human male does spermatogenesis occur?

Identify the chromosomal abnormalities as well as the physical features present in a person suffering from Turner syndrome.

A lattice holds the members of a bivalent together in such a way that the RNA of the nonsister chromatids is aligned.

A primary spermatocyte has 64 chromosomes.After meiosis I,each secondary spermatocyte would have 32 chromosomes.After meiosis II,each spermatid would have 16 chromosomes.

During which stage of meiosis does crossing-over occur?

If a sperm cell contains 8 chromosomes,it comes from an animal whose regular body cells have ________ chromosomes.

Which of the following statements is true about the life cycle of animals?

Which of the following would NOT contribute to genetic variation?

Meiosis occurs during all of the following EXCEPT

In human females,when is meiosis II completed?

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