Chapter 8 Key Terms

Question 1

Beginning when sister chromatids separate from each other and ending when a complete set of daughter chromosomes has arrived at each of the two poles of the cell

Answer 1

Anaphase

Question 2

A chromosome not directly involved in determining the sex of an organism; in mammals, for example, any chromosome other than X or Y

Answer 2

Autosome

Question 3

An abnormal mass of cells that remains at its original site in the body

Answer 3

Benign Tumor

Question 4

An ordered sequence of events (including interphase and mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell until it’s own division in two cells

Answer 4

Cell Cycle

Question 5

The reproduction of a cell

Answer 5

Cell Division

Question 6

The region of a chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. The centromere divides at the onset of anaphase during mitosis and anaphase II of meiosis.

Answer 6

Centromere

Question 7

The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane.

Answer 7

Cleavage

Question 8

The exchange of segments between chromatids of homologous chromosomes during prophase I of meiosis.

Answer 8

Crossing Over

Question 9

The division of the cytoplasm to form two separate daughter cells. Cytokinesis usually occurs during telophase of mitosis, and the two processes (mitosis and cytokinesis) make up the mitotic (M) phase of the cell cycle.

Answer 9

Cytokinesis

Question 10

Containing two sets of chromosomes (pairs of homologous chromosomes) in each cell, one set inherited from each parent; referring to a 2n cell.

Answer 10

Diploid

Question 11

The union of a haploid sperm cell with a haploid egg cell, producing a zygote.

Answer 11

Fertilization

Question 12

A sex cell; a haploid egg or sperm. The union of two gametes of opposite sex (fertilization) produces a zygote.

Answer 12

Gamete

Question 13

Containing a single set of chromosomes; referring to an n cell.

Answer 13

Haploid

Question 14

The two chromosomes that make up a matched pair in a diploid cell. Homologous chromosomes are of the same length, centromere position, and staining pattern and possess genes for the same characteristics at corresponding loci. One homologous chromosome is inherited from the organism’s father, the other from the mother.

Answer 14

Homologous Chromosomes

Question 15

The phase in the eukaryotic cell cycle when the cell is not actually dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase accounts for 90% of the cell cycle. See also mitosis.

Answer 15

Interphase

Question 16

A display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position.

Answer 16

Karyotype

Question 17

An abnormal tissue mass that spreads into neighboring tissue and to other parts of the body; a cancerous tumor.

Answer 17

Malignant Tumor

Question 18

In a sexually reproducing organism, the process of cell division that produces haploid gametes from diploid cells within the reproductive organs.

Answer 18

Meiosis

Question 19

The second stage of mitosis. During metaphase, the centromeres of all the cell’s duplicated chromosomes are lined up along the center line of the cell.

Answer 19

Metaphase

Question 20

The division of a single nucleus into two genetically identical daughter nuclei. Mitosis and cytokinesis make up the mitotic (M) phase of the cell cycle.

Answer 20

Mitosis

Question 21

The phase of the cell cycle when mitosis divides the nucleus and distributes its chromosomes to the daughter nuclei and cytokinesis divides the cytoplasm, producing two daughter cells.

Answer 21

Mitotic Phase

Question 22

A spindle-shaped structure formed of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis and meiosis. (A spindle is shaped roughly like a football.)

Answer 22

Mitotic Spindle

Question 23

An accident of meiosis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fails to separate at anaphase.

Answer 23

Nondisjunction

Question 24

The bead-like unit of DNA packing in a eukaryotic cell; consists of DNA wound around a protein core made up of eight histone molecules.

Answer 24

Nucleosome

Question 25

The first stage of mitosis. During prophase, duplicated chromosomes condense to form structures visible with a light microscope, and the mitotic spindle forms and begins moving the chromosomes toward the center of the cell.

Answer 25

Prophase

Question 26

One of the two identical parts of a duplicated chromosome. While joined, two sister chromatids make up one chromosome; chromatids are eventually separated during mitosis or meiosis II.

Answer 26

Sister Chromatid

Question 27

The fourth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. Telophase usually occurs together with cytokinesis.

Answer 27

Telophase

Question 28

The fertilized egg, which is diploid, that results from the union of haploid gametes (sperm and egg) during fertilization.

Answer 28

Zygote