The Cell Cycle

Question 1

Unicellular Organisms

Answer 1

Reproduce by cell division

Question 2

Multicellular Organisms

Answer 2

Cell division for development of fertilized cell, growth, repair

Question 3

Cell Division

Answer 3

Some cells divide repeatedly (skin, blood cells, cheek cells)

Some cells stay alive, but don’t divide (muscle and nerve)

Some cells divide infrequently (bones)

Results in identical daughter cells

Cell duplicates its DNA before dividing

Question 4

DNA

Answer 4

Genetic material

Packaged into chromosomes

2m long

Question 5

Chromatin

Answer 5

Complex of DNA and protein

Condenses to chromosomes in cell division

Question 6

Chromosomes

Answer 6

2 sets of each chromosome (diploid)

Gametes have one set (haploid)

Humans have 23 sets

Question 7

Binary Fission

Answer 7

Single bacterial chromosome duplicates

Daughters move apart

Membrane grows inward

Cell divides

Question 8

Mitosis

Answer 8

Division of the nucleus, after DNA is replicated

Chromatids splits

2 equal cells

Question 9

Cytokinesis

Answer 9

Division of cytoplasm

Question 10

Meiosis

Answer 10

Replicate DNA once

Split cell twice

Question 11

Interphase

Answer 11

Chromosomes duplicate

Cell parts are made

Question 12

G1 Phase

Answer 12

Longest phase

Growth

Multiplies organelles

Stops after growth -checkpoint

Question 13

S Phase

Answer 13

Cell synthesizes/duplicates DNA

Question 14

G2 Phase

Answer 14

Cell grows

Centrioles replicate

Multiplies organelles

Another checkpoint

Question 15

G0

Answer 15

Permanent stop after G1

Never replicate

Example- muscle or nerve

Question 16

Prophase

Answer 16

Chromatin condenses to chromosomes

Mitotic spindles form

Centrosomes start to move apart

Nuclear envelope begins to dissolve

Question 17

Mitotic Spindles

Answer 17

Microtubules

Controls chromosome movement

Arise from centrosomes

Includes asters

Some attach to kinetochore and some move chromosome to metaphase plate

Question 18

Aster

Answer 18

Anchor centrosomes

Question 19

Kinetochore

Answer 19

Centromere separates into two kinetochore proteins

Question 20

Pro-metaphase

Answer 20

Nuclear envelop disappears

Kinetochore proteins appear

Spindles from chromatids to centrosomes

Question 21

Metaphase

Answer 21

Midline

Mitotic spindles fully formed

Centromeres lined up on mid-line plate

Question 22

Anaphase

Answer 22

Outta here

Centromeres pull apart

Chromosomes move to opposite ends

Cell Elongates

Spindles connected to kinetochores move chromatids to ends of cells, the other spindles overlap and such against each other to elongate the cell

Question 23

Telophase

Answer 23

Mitotic spindles dissolve

Nuclear envelop reforms

Chromosomes become chromatin

Cytokinesis

Question 24

Cytokinesis

Answer 24

Division of cytoplasm

Occurs telophase

Cleavage furrow riches cell in two

New cells enter into interphase after this

Question 25

Mitosis in Plants

Answer 25

Cell plate forms during cytokinesis

Question 26

Cell Cycle Control System

Answer 26

Has specific checkpoints Stops until a go ahead signal is received Checkpoints- G1 passed if nutrients sufficient, cell size big enough, and DNA undamaged (hardest to get by) Growth factor hormones can trigger cell division (tells us we need more cells)

Question 27

Regulatory Protein

Answer 27

Involved in cell cycle control Cyclin and cyclin-dependent kinases (Cdks) Form maturation promoting factor(MPF) which triggers mitosis

Question 28

Density-Dependent Inhibition

Answer 28

Crowded cells stop dividing

Question 29

Anchorage Dependent

Answer 29

Cells must be attached to substratum to divide

Question 30

Cancer Cells

Answer 30

No density dependence inhibition or anchorage dependence Do not respond to body's control mechanism Form Tumors