Biology 122 Answers to Review

Posted: September 16, 2019

10-2 p. 249 #1 - 6

1.  During the cell cycle, a cell grows (G1), copies its chromosomes (S), prepares for division (G2), and divides to form two daughter cells (M).

2. G1 - the cell grows and carries out its day-to-day activities; S - synthesis phase; the chromosomes are copied, resulting in identical sister chromatids; G2 - the cell makes additional organelles, and prepares to divide; M - the cell goes through prophase, metaphase, anaphase, telophase, and cytokinesis to divide its chromosomes and cytoplasm

3. Interphase is made up of G1, S, and G2 phases, during which the cell grows, copies DNA, and prepares to divide.

4. Chromosomes are made of DNA (coded genetic information) and protein.

5. A prokaryotic cell replicates its genetic material (often just a single, circular chromosome), then undergoes binary fission to separate the cell contents into two daughter cells.

6. Cytokinesis is the division of the cytoplasm in both plant and animal cells. The difference is that in plant cells, a cell plate forms midway between the divided nuclei.

 

10-3 p. 252 # 1- 4

1. Cyclins regulate the timing of the cell cycle in eukaryotic cells.  Cyclin may cause a mitotic spindle to form and trigger cell division.

2. Such cells, called cancer cells, divide uncontrollably and form masses of cells called tumours that can damage surrounding tissues, and/or spread to other parts of the body.

3. Normal cells would stop growing when they come in contact with other cells.

4. The cell cycle is a series of evens that cells go through as they divide, and cancer is a disorder in which some of the body's cells lose the ability to regulate their growth.