Question: A replicated chromosome consists of

Answer: two sister chromatids.

FEEDBACK: A replicated chromosome consists of two sister chromatids that are held together at the centromere. During S phase, the replicated chromosomes are produced in preparation for mitosis. It is during mitosis that the replicated chromosome is split in two.

Question: During crossing over,

Answer: homologous chromosomes exchange genetic information.

FEEDBACK: Maternal and paternal homologs pair up and exchange genetic information during prophase I of meiosis. The result is that daughter cells are not identical to the parent cell that produced them.

Question: During which of the following phases of mitosis do replicated chromosomes line up at an invisible plane along the center of the cell?

Answer: metaphase

FEEDBACK: During mitosis, replicated chromosomes are pushed back and forth until they wind up in the center of the cell. The mitotic spindle is the structure that relocates chromosomes in this fashion. At metaphase the replicated chromosomes line up at the metaphase plate.

Question: In which of the following stages of mitosis would you expect to see chromatids become daughter chromosomes?

Answer: anaphase

FEEDBACK: Sister chromatids separate and become daughter chromosomes during anaphase of mitosis. During telophase they will be packaged into daughter nuclei and ultimately during cytokinesis they will wind up in separate cells.

Question: The form of eukaryotic cell division that produces two genetically identical cells is

Answer: mitosis.

FEEDBACK: Eukaryotic cells divide asexually via mitosis. Since this process only involves a single mother cell, it produces genetically identical offspring called daughter cells.

Question: The most important characteristic that distinguishes meiosis from mitosis is

Answer: the total number of chromosomes present in daughter cells.

FEEDBACK: Recall that the overall purpose of mitosis is to make genetically identical daughter cells (diploid parent cell to diploid daughter cells), whereas the purpose of meiosis is to reduce the number of chromosomes by half (diploid parent cell to haploid daughter cells).

Question: The structure highlighted in the figure below corresponds to a

Answer: duplicated chromosome.

FEEDBACK: In preparation for cell division, chromosomes are copied during S phase to produce duplicated chromosomes. Two identical sister chromatids held together at the centromere.

Question: What purposes do crossing over and independent assortment play in cell division?

Answer: They help to add genetic diversity to daughter cells.

FEEDBACK: Along with random fertilization, these processes help to promote genetic diversity among daughter cells. Diversity is important since it is the raw material that drives the process of evolution.

Question: Which of the following explains why a cell might undergo meiosis?

Answer: to produce egg and sperm cells

FEEDBACK: Meiosis is the process that makes sex cells (eggs and sperm) in sexually reproducing eukaryotes. Meiosis only occurs in specialized organs within eukaryotes, whereas mitosis is used for the production of many different types of cells.

Question: Which of the following processes divides the cytoplasm of cells following mitosis?

Answer: cytokinesis

FEEDBACK: Cell division occurs over two processes - nuclear division and cytoplasmic division. Nuclear division evenly partitions the chromosomes, whereas cytokinesis separates the contents of the cytoplasm, which includes organelles and other cellular structures.