Meiosis

crossing over may occur.

I. prophase I
II. metaphase I
III. anaphase I
IV. telophase I
V. prophase II
VI. metaphase II
VII. anaphase II
VIII. telophase II

In a cell in which 2n = 6, the independent assortment of chromosomes during meiosis can by itself give rise to ________ genetically different gametes.
A) two
B) four
C) five
D) six
E) eight

Centromeres of sister chromatids uncouple and chromatids separate.
I. prophase I
II. metaphase I
III. anaphase I
IV. telophase I
V. prophase II
VI. metaphase II
VII. anaphase II
VIII. telophase II

Which of the following statements about genes is incorrect?
A) Genes correspond to segments of DNA.
B) Many genes contain the information needed for cells to synthesize enzymes and other proteins.
C) During fertilization, both the sperm and the ovum contribute genes to the resulting fertilized egg.
D) Under normal circumstances, each chromosome contains precisely one gene.
E) Genetic differences can result from changes in the DNA called mutations.

Which of the following is true of a species that has a chromosome number of 2n = 16?
A) The species is diploid with 32 chromosomes.
B) The species has 16 sets of chromosomes.
C) There are 8 homologous pairs.
D) During the S phase of the cell cycle there will be 32 separate chromosomes.
E) A gamete from this species has 4 chromosomes.

Independent assortment of chromosomes occurs.
A. The statement is true for mitosis only.
B. The statement is true for meiosis I only.
C. The statement is true for meiosis II only.
D. The statement is true for mitosis and meiosis I.
E. The statement is true for mitosis and meiosis II.

Which of the following is true of the process of meiosis?
A) Two diploid cells result.
B) Four diploid cells result.
C) Four haploid cells result.
D) Four autosomes result.
E) Four chiasmata result.

1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus
2. alignment of tetrads at the metaphase plate
3. separation of sister chromatids
4. separation of the homologues; no uncoupling of the centromere
5. synapsis; chromosomes moving to the middle of the cell in pairs

Which of the steps take place in both mitosis and meiosis?
A) 2
B) 3
C) 5
D) 2 and 3 only
E) 2, 3, and 5

Which of the following is the term for a human cell that contains 22 pairs of autosomes and two X chromosomes?
A) an unfertilized egg cell
B) a sperm cell
C) a male somatic cell
D) a female somatic cell
E) both A and D

1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus
2. alignment of tetrads at the metaphase plate
3. separation of sister chromatids
4. separation of the homologues; no uncoupling of the centromere
5. synapsis; chromosomes moving to the middle of the cell in pairs

From the descriptions above, which of the following is the order that most logically illustrates a sequence of meiosis?

Tetrads of chromosomes are aligned at the center of the cell; independent assortment soon follows.
I. prophase I
II. metaphase I
III. anaphase I
IV. telophase I
V. prophase II
VI. metaphase II
VII. anaphase II
VIII. telophase II

The process is preceded by replication of the DNA.
A. The statement is true for mitosis only.
B. The statement is true for meiosis I only.
C. The statement is true for meiosis II only.
D. The statement is true for mitosis and meiosis I.
E. The statement is true for mitosis and meiosis II.

What is a karyotype?
A) the set of unique physical characteristics that define an individual
B) the collection of all the mutations present within a genome
C) a unique combination of chromosomes found in a gamete
D) a system of classifying cell nuclei
E) a display of every pair of homologous chromosomes within a cell, organized according to size and shape

Independent assortment of chromosomes is a result of
A) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.
B) the random nature of the fertilization of ova by sperm.
C) the random distribution of the sister chromatids to the two daughter cells during anaphase II.
D) the relatively small degree of homology shared by the X and Y chromosomes.
E) all of the above

How do the two members of a pair of homologous chromosomes differ from each other?
A) their length
B) the identity and relative position of the genes present on each of the chromosomes
C) their staining patterns
D) the position of the centromere within each of the chromosomes
E) the precise sequence of the DNA within each of the chromosomes

What is a karyotype?
A) the set of unique physical characteristics that define an individual
B) the collection of all the mutations present within a genome
C) a unique combination of chromosomes found in a gamete
D) a system of classifying cell nuclei
E) a display of every pair of homologous chromosomes within a cell, organized according to size and shape

For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?
A) 23
B) 46
C) 460
D) 920
E) about 8 million

At the end of ________ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
A) metaphase II
B) telophase I
C) telophase
D) telophase II
E) interphase

After telophase I of meiosis, the chromosomal makeup of each daughter cell is
A) diploid, and the chromosomes are composed of a single chromatid.
B) diploid, and the chromosomes are composed of two chromatids.
C) haploid, and the chromosomes are composed of a single chromatid.
D) haploid, and the chromosomes are composed of two chromatids.
E) tetraploid, and the chromosomes are composed of two chromatids.

If the liver cells of an animal have 24 chromosomes, how many chromosomes do its sperm cells have?
A) 6
B) 12
C) 24
D) 48
E) 64

At which stage of mitosis are chromosomes photographed in the preparation of a karyotype?
A) prophase
B) metaphase
C) anaphase
D) telophase
E) interphase

The human X and Y chromosomes are
A) both present in every somatic cell of males and females alike.
B) of approximately equal size.
C) almost entirely homologous, despite their different names.
D) called "sex chromosomes" because they determine an individual's sex.
E) all of the above

You have in your possession a microscope slide with meiotic cells on it and a light microscope. What would you look for if you wanted to identify metaphase I cells on the slide?
A) a visible nuclear envelope
B) separated sister chromatids at each pole of the cell
C) tetrads lined up at the center of the cell
D) a cleavage furrow
E) none of the above

Homologous chromosomes migrate to opposite poles during
A) telophase II and cytokinesis.
B) prophase II.
C) anaphase I.
D) metaphase I.
E) metaphase II.

What is a genome?
A) the complete complement of an organism's genes
B) a specific sequence of polypeptides within each cell
C) a specialized polymer of four different kinds of monomers
D) a specific segment of DNA that is found within a prokaryotic chromosome
E) an ordered display of chromosomes arranged from largest to smallest

Which of the following happens at the conclusion of meiosis I?
A) Homologous chromosomes are separated.
B) The chromosome number is conserved.
C) Sister chromatids are separated.
D) Four daughter cells are formed.
E) The sperm cells elongate to form a head and a tail end.