Chapter 17

Question 1

Summarize the cell cycle

Answer 1

● G1 phase. The cell cycle begins with G1 (“first gap”), the period between the last cell division and DNA synthesis. At the start of G1, the cell is at its smallest size. G1 is a period of very active cell growth.
● S phase. The S stands for “synthesis” of DNA. During the S phase, the cell’s chromosomes are duplicated. Growth continues throughout the S phase, although at a slower pace than in the G1 phase.
● G2 phase. During G2 (“second gap”), the cell continues to grow slowly as it prepares for cell division

Question 2

One of two major periods in the cell life cycle. Includes the period from cell formation to cell division.

Answer 2

interphase

Question 3

Process of nuclear division during which duplicated chromosomes are distributed to two daughter nuclei, each with the same number of chromosomes as the parent cell. Mitosis consists of prophase, metaphase, anaphase, and telophase

Answer 3

mitosis

Question 4

Rodlike structure of tightly coiled chromatin. Visible in the nucleus during cell division.

Answer 4

chromosome

Question 5

The unit of heredity. Most genes encode for specific polypeptides, and each gene has a specific location on a particular chromosome

Answer 5

gene

Question 6

The process of copying the cell’s DNA prior to cell division

Answer 6

Replication

Question 7

The process of creating a coded message of a single gene that can be carried out of the nucleus.

Answer 7

Transcription

Question 8

The process of converting the coded message into proteins useful to the cell.

Answer 8

Translation

Question 9

The division of cytoplasm that occurs after a cell nucleus has divided

Answer 9

cytokinesis

Question 10

The first stage of mitosis. During prophase the chromosomes condense and thicken, the pairs of centrioles migrate to opposite sides of the cell, and the mitotic spindle forms.

Answer 10

prophase

Question 11

Second stage of mitosis, during which the chromosomes align themselves on one plane at the center of the cell.

Answer 11

metaphase

Question 12

Third stage of mitosis, in which the two sets of daughter chromosomes move toward the poles of a cell.

Answer 12

anaphase

Question 13

In cell division, the last phase of mitosis in which the two new sets of chromosomes arrive at opposite poles of the cell, new nuclear membranes form around the chromosomes, and the chromosomes uncoil and are no longer visible under a microscope.

Answer 13

telophase

Question 14

The division of cytoplasm that occurs after a cell nucleus has divided

Answer 14

Cytokinesis

Question 15

The number of chromosomes in a body cell (2n), twice the chromosomal number (n) of a gamete. In humans, 2n = 46.

Answer 15

diploid

Question 16

) Half the diploid number of chromosomes; the number of chromosomes in a gamete.

Answer 16

haploid

Question 17

What process produces haploid gametes (eggs or sperm)?

Answer 17

meiosis

Question 18

What are some cells that divide constantly through life? Normally don’t divide in adulthood?

Answer 18

Nerve cells muscle cells osteocytes