Chapter 10 - Cell Division & Mitosis

Question 1

Function of cell division in single-celled organisms

Answer 1

asexual reproduction

Question 2

Function of cell division in multicellular organisms

Answer 2

growth & repair

Question 3

Chromosome

Answer 3

structure of nucleic acids in which DNA & genes are transferred from parent to offspring

Question 4

Sister chromatids

Answer 4

replicated chromosomes that attach at their centromere center –> form the X shape

Question 5

Homologous chromosomes

Answer 5

pairs of compatible chromosomes –> one chromosome from each parent

Question 6

Gene

Answer 6

unit of heredity comprised of specific nucleotide sequence on a chromosome

Question 7

Chromatin

Answer 7

strands of DNA wrapped around a mass of positively charged histone proteins to form a nucleosome that will coil with other nucleosomes to form chromatin

Question 8

Histone

Answer 8

positively charged protein around which the negatively charged phosphate groups of the nucleic acids that comprise DNA will attach to & wrap around

Question 9

Euchromatin structure

Answer 9

loosely packed DNA molecules on which work can be performed because there is space for proteins
-if the cell needs to undergo transcription, its chromosomes will enter a euchromatin structure

Question 10

Heterochromatin

Answer 10

tightly packed DNA molecules on which work cannot be done because there is no space for proteins to access the individual histone proteins to manipulate the DNA

Question 11

Centromere

Answer 11

the middle of the sister chromosome on which the mitotic spindle will attach via the system of proteins forming the kinetochore

Question 12

G1 checkpoint

Answer 12

occurs before S phase –> checks for proper cell size, sufficient nutrients, the presence of social signals, & ensures there is undamaged DNA

Question 13

G2 checkpoint

Answer 13

occurs before mitosis begins –> checks to ensure the cell is ready to undergo mitosis

Question 14

M phase checkpoint

Answer 14

occurs before anaphase –> Ensures the chromosomes are attached to microtubules at their kinetochore & have segregated properly

Question 15

Cyclins

Answer 15

proteins that are present only at certain times during the cell cycle when they are needed for progression from one stage to the next

Question 16

Cyclin-dependent kinase (CDK)

Answer 16

enzymes that are present all the time within cells but are only present when bound to a cyclin
-function to phosphorylate cells to move to the next phase of the cell cycle

Question 17

Oncogenes

Answer 17

mutated proto-oncogene that can cause cancer by uncontrolled cell division

Question 18

p53/tumor suppressor genes

Answer 18

genes that search for DNA damage –> when these genes are mutated, damaged DNA will be allowed to replicate throughout the cell, causing cancer by uncontrolled cell division

Question 19

Proto-oncogenes

Answer 19

normal, not yet cancerous cell genes