Ch. 12 Vocab

Question 1

an ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two

Answer 1

cell cycle

Question 2

the complex of DNA and proteins that makes up a eukaryotic chromosome

Answer 2

chromatin

Question 3

the specialized region of the chromosome where two sister chromatids are most closely attached

Answer 3

centromere

Question 4

cellular structures carrying genetic material, found in the nucleus of eukaryotic cells; consists of one very long DNA molecule and associated proteins

Answer 4

chromosomes

Question 5

the division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II

Answer 5

cytokinesis

Question 6

structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule-organizing center

Answer 6

centrosome

Question 7

the first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate

Answer 7

cleavage furrow

Question 8

the process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; the succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells

Answer 8

cleavage

Question 9

a double membrane across the midline of a dividing plant cell, between which the new cell forms during cytokinesis

Answer 9

cell plate

Question 10

a cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle

Answer 10

cell cycle control system

Question 11

a control point in the cell cycle where stop and go-ahead signals can regulate the cycle

Answer 11

checkpoint

Question 12

a cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle

Answer 12

cyclin

Question 13

a protein kinase that is active only when attached to a particular cyclin

Answer 13

cyclin-dependent kinase (Cdk)

Question 14

the fourth stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell

Answer 14

anaphase

Question 15

the requirement that a cell must be attached to a substratum in order to divide

Answer 15

anchorage dependence

Question 16

a method of asexual reproduction by “division of half”

Answer 16

binary fission

Question 17

a mass of abnormal cells that remains at the site of its origin

Answer 17

benign tumor

Question 18

the phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another

Answer 18

density-dependent inhibition

Question 19

a radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis

Answer 19

aster

Question 20

the genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its no coding nucleic acid sequences

Answer 20

genome

Question 21

haploid reproductive cells, such as eggs or sperm

Answer 21

gametes

Question 22

the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins

Answer 22

G1 phase

Question 23

the second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs

Answer 23

G2 phase

Question 24

a no dividing state occupied by cells that have left the cell cycle

Answer 24

G0 phase

Question 25

a protein that must be present in the extra cellular environment for the growth and normal development of certain types of cells; a local regulator that acts on nearby cells to stimulate cell proliferation and differentiation

Answer 25

growth factor

Question 26

the period in the cell cycle when the cell is not dividing

Answer 26

interphase

Question 27

a structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle

Answer 27

kinetochore

Question 28

a process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, telophase

Answer 28

mitosis

Question 29

the phase of the cell cycle that includes mitosis and cytokinesis

Answer 29

mitotic (M) phase

Question 30

a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication

Answer 30

meiosis

Question 31

the third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate

Answer 31

metaphase

Question 32

an imaginary plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located

Answer 32

metaphase plate

Question 33

an assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis

Answer 33

mitotic spindle

Question 34

a cancerous tumor that is invasive enough to impair the functions of one or more organs

Answer 34

malignant tumor

Question 35

the spread of cancer cells to locations distant from their original site

Answer 35

metastasis

Question 36

the second stage of mitosis, in which discrete chromosomes consisting of identical sister chromatids appear, the nuclear envelope fragments, and the spindle microtubules attach to the kinetochores of the chromosomes

Answer 36

prometaphase

Question 37

the first stage of mitosis, in which the chromatin condenses, the mitotic spindle begins to form, and the nucleolus disappears, but the nucleus remains intact

Answer 37

prophase

Question 38

any cell in a multicellular organism except a sperm or egg

Answer 38

somatic cells

Question 39

either of two copies of duplicated chromosomes attached to each other by proteins at the centromere and, sometimes, along the arms

Answer 39

sister chromatids

Question 40

the synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated

Answer 40

S phase

Question 41

the fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun

Answer 41

telophase

Question 42

the conversion of a normal animal cell to a cancerous cell; a change in genotype and phenotype due to the assimilation of external DNA by a cell

Answer 42

transformation

Question 43

short stretches of DNA having a specific sequence of nucleotides

Answer 43

origin of replication

Question 44

the reproduction of cells

Answer 44

cell division