SAT Cell Division: Mitosis and Meiosis 3

Question 1

What is the primary purpose of the G2 checkpoint in the cell cycle?

Accepted Answer

To ensure DNA replication is complete and accurate before mitosis begins

Answer

To check if the cell has grown large enough to divide

Answer

To ensure chromosomes have aligned at the metaphase plate

Answer

To prevent the cell from entering S phase

Question 2

What is nondisjunction, and what is its primary consequence?

Accepted Answer

Failure of homologous chromosomes or sister chromatids to separate properly, resulting in aneuploidy

Answer

Failure of the nuclear envelope to break down, preventing chromosome separation

Answer

Failure of crossing over to occur, reducing genetic variation

Answer

Failure of cytokinesis, producing a binucleate cell

Question 3

Which processes during meiosis most directly contribute to genetic variation in offspring?

Accepted Answer

Crossing over during prophase I and independent assortment of homologs

Answer

DNA replication during S phase

Answer

Identical division during meiosis II

Answer

Formation of the spindle apparatus

Question 4

Which of the following events characterizes telophase of mitosis?

Accepted Answer

Nuclear envelopes reform around each set of chromosomes at the poles

Answer

Chromosomes condense and become visible under the microscope

Answer

Sister chromatids separate and move to opposite poles

Answer

Homologous chromosomes pair up to form tetrads

Question 5

What is the key difference between mitosis and meiosis in terms of number of cell divisions and final cell count?

Accepted Answer

Mitosis involves one division producing two diploid cells; meiosis involves two divisions producing four haploid cells

Answer

Mitosis involves two divisions producing four cells; meiosis involves one division producing two cells

Answer

Both processes involve exactly one division producing two cells

Answer

Mitosis involves three divisions; meiosis involves two divisions

Question 6

In which types of organisms does meiosis occur?

Accepted Answer

Only in sexually reproducing eukaryotes

Answer

All living organisms, including prokaryotes

Answer

Only in bacteria during binary fission

Answer

All eukaryotes, including those that reproduce only asexually

Question 7

What is the biological significance of the S phase in the cell cycle?

Accepted Answer

Each chromosome is duplicated so both daughter cells receive a complete, identical genome

Answer

The cell grows and produces organelles in preparation for division

Answer

The cell undergoes programmed death if DNA damage is irreparable

Answer

Proteins for the spindle apparatus are synthesized