BIO Ch. 16 Lecture Assignment

Humans have ________ different types of autosomes.

22

Consider an organism whose karyotype shows it to have a total of 60 chromosomes. How many chromosomes would be contained in the sperm of this organism?

30

In a tetraploid species, a euploid individual would have ________ sets of chromosomes.

4

A species that three sets of homologous chromosomes can have ________ different combinations of chromosomes in its gametes.

8

Polyploidy in plants

All of these statements are true regarding polyploidy in plants

The following graph represents the concentration of cyclins over the course of the cell cycle. Which of the following statements is TRUE regarding the phase of the cell cycle where the green arrow is pointing?(M-cyclin)

At this point in the cell cycle, chromosomes have properly aligned on the METAPHASE PLATE and are beginning to separate.

The following graph represents the concentration of cyclins over the course of the cell cycle. Which of the following statements is TRUE regarding the phase of the cell cycle where the red arrow is pointing?(G1/S-cyclin)

At this point in the cell cycle, the cell is determining if conditions are FAVORABLE for cell division.

The following graph represents the concentration of cyclins over the course of the cell cycle. Which of the following statements is TRUE regarding the phase of the cell cycle where the blue arrow is pointing?(S-cyclin)

At this point in the cycle the cell is continuing to grow and make abundant tubulin proteins.

The following graph represents the concentration of cyclins over the course of the cell cycle. Which of the following statements is TRUE regarding the cell cycle where the red arrow is pointing?

CDK proteins are actively phosphorylating proteins that are involved in DNA replication.

Which of the following occurs during metaphase?

Chromosomes are much shorter than they were in interphase

Which of the following is NOT a checkpoint that controls the progression of the cell cycle?

Cytokinesis involves the formation of cleavage furrow to separate the cells.

What does not happen in the cytokinesis of plant cells?

Formation of cleavage furrow to separate the cells.

Put the following steps in the procedure for producing a karyotype in the correct order. I. Cells are visualized under the microscope. II. Cells are stimulated to divide. III. Homologues are organized into sets by matching size and banding patterns. IV. The cells are exposed to a hypotonic solution. V. Cells are stained and placed on a microscope slide.

II, IV, V, I, III

Place the following events of mitosis in the correct order. I. Sister chromatids align on the metaphase plate. II. The cleavage furrow forms. III. The nuclear membrane breaks up. IV. Sister chromatids condense. V. Sister chromatids separate.

IV, III, I, V, II

Which of the following statements regarding the G1 (first gap) phase of the eukaryotic cell cycle is NOT true?

If environmental conditions are favorable during the G1 phase, G1 cyclins are DEGRADED causing the cell to prepare to replicate its DNA.

Why are sex chromosome aneuploidies less detrimental than autosomal aneuploidies?

In females, all but one X-chromosome is inactivated; in males, the Y chromosome contains very few genes, so extra or missing copies do not cause huge abnormalities.

A male who inherits an extra X chromosome will have

Kleinfelter syndrome

Why must the life cycle of sexually reproducing species alternate between haploid and diploid stages?

MEIOSIS must occur at some point in the life cycle to prevent a DOUBLING of chromosomes in each generation.

DNA associates very tightly with nucleosomes because

NEGATIVE CHARGES on DNA are attracted to positive charges of the histone proteins

Chromosomes are replicated during the ________ phase.

S

Which of the following statements about sister chromatids is TRUE?

Sister chromatids are exact copies of each other and are formed just prior to cell division.

Which of the following statements is FALSE concerning sister chromatids?

Sister chromatids separate during telophase.

Colchicine is a toxin that binds to tubulin proteins and prevents microtubules from elongating. What effect might this have on dividing cells?

Sister chromatids will NOT be PROPERLY SEPERATED into separate daughter cells.

A mutation occurs in a gene that encodes a G1 cyclin, such that the protein is unable to bind to its CDK. How will this affect the cell cycle?

The cell will be STUCK in G1 and WILL NOT ADVANCE through the cell cycle

When a gamete that is lacking a sex chromosome due to nondisjunction has fused with a gamete carrying an X chromosome, this type of abnormality leads to ________.

Turner syndrome

Which of the following statements about the cell cycle is correct?

When the S phase of the cell cycle is finished, a cell has twice as many chromatids as the number of chromosomes in the G1 phase.

During crossing over in meiosis, an unequal exchange of genetic material occurs. This would most likely produce

a deficiency in one homologue and a duplication in the other homologue

Sister chromatids separate during

anaphase of meiosis II

Consider a diploid species where n = 5. If an individual of this species was found to have 11 chromosomes, it would be categorized as

aneuploid

Most human embryos that are aneuploid

are SPONTANEOUSLY ABORTED in the first trimester

You prepare the first ever karyotype of an endangered species of frog. Upon examination you find that all the chromosomes are metacentric. This is going to make it difficult to identify

both the p and q arms of the chromosome

Which of the following is NOT a part of the mitotic spindle apparatus in plants?

centrioles

The formation of the bivalent during meiosis

contributes to the genetic diversity of a species

A chromosome with the centromere located two-thirds of the distance from its end could be classified as

either submetacentric or acrocentric

For any given species, cells in metaphase II of meiosis would contain two times more genetic material than cells in metaphase of mitosis.(t/f)

false

Homologous chromosomes are identical copies of each other.(t/f)

false

If a cell contains 20 chromosomes in G1, it will contain 40 chromosomes at the end of S.(t/f)

false

Mitotic cell division is never used by organisms as a means of reproduction.(t/f)

false

The karyotype of a normal human male would show a total of 23 pairs of homologous chromosomes.(t/f)

false

The major way that meiosis II differs from mitosis is that

in meiosis II, the daughter cells are haploid

Which of the following mutations will NOT alter the amount of genetic material of a chromosome?

inversion

The centromere

is a region of DNA where sister chromatids associate.

The process by which haploid cells are produced from diploid cells is called

meiosis

The life cycle of a sexually reproducing organisms includes

mitosis, meiosis, and fusion of the gametes.

In mitosis, the main difference between plant and animal cells is that

plants produce a cell plate to segregate the daughter nuclei, while animals form a cleavage furrow

Synaptonemal complexes form during

prophase of meiosis I

At the end of meiosis I

the cells are Haploid and the homologous pairs are in separate cells

Cytogenetics is

the field of genetics that involves the microscopic examination of the chromosomes and cell division

In a haploid dominant species

the multicellular organism is haploid, and only the zygote is diploid

How are sister chromatids connected to each other?

through cohesion proteins

A cell undergoing meiosis that contains sister chromatids may be either haploid or diploid.(t/f)

true

One major difference between metaphase I and metaphase II is the presence or absence of bivalents.(t/f)

true

Sexual life cycles include both haploid and diploid stages.(t/f)

true

Consider a cell in which nondisjunction occurs for all chromosomes during meiosis I. What would be the result of this event?

two aneuploid gametes, each with an EXTRA SET of chromosomes

Meiosis I produces ________, and meiosis II produces ________ cells.

two haploid, 4 haploid