Ch.12: The Cell Cycle

Question 1

The continuity of life is based on the reproduction of cells, or

Answer 1

cell division

Question 2

What do all organisms and cells have in common

Answer 2

All organisms are composed of cells

Cells reproduce themselves

Question 3

division of one cell reproduces the entire organism

Answer 3

unicellular organisms

Question 4

Multicellular organisms depend on cell division for:

Answer 4

Development
Growth/Repair
Asexual reproduction

Question 5

the division of the nucleus

Answer 5

mitosis

Question 6

the division of the cytoplasm

Answer 6

cytokinesis

Question 7

What must be divided perfectly during mitosis, and Why?

Answer 7

chromosomes, so that it resembles the parent cell perfectly

Question 8

All the DNA in a cell constitutes the cell’s _________; can consist of a single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells)

Answer 8

genome

Question 9

(body cells) have two sets of chromosomes (Diploid=2n)

Answer 9

Somatic Cells

Question 10

(sperm and eggs) have only one set of chromosomes (Haploid=n)

Answer 10

Gametes

Question 11

When cells are not dividing the DNA is in the form of _________; DNA and protein that are uncondensed and functional

Answer 11

Chromatin

Question 12

In preparation for cell division, what occurs

Answer 12

DNA must be replicated and the chromosomes formed

Question 13

Each duplicated chromosome has

Answer 13

two sister chromatids (must separate)

Question 14

The __________ is the narrow “waist” of the duplicated chromosome, where the two chromatids are most closely attached

Answer 14

centromere

Question 15

The cell cycle consists of

Answer 15

Mitotic phase (mitosis & cytokinesis)
Interphase (cell growth and copying of chromosomes in preparation for cell division)

Question 16

Interphase:

Answer 16

about 90% of the cell cycle) can be divided into subphases:	
G1 phase (“first gap”)
S phase (“synthesis”) Where DNA is replicated
G2 phase (“second gap”)

Question 17

Mitosis is conventionally divided into five phases:

Answer 17

Prophase
Prometaphase
Metaphase
Anaphase
Telophase

Question 18

an apparatus of microtubules that controls chromosome movement during mitosis

Answer 18

mitotic spindle

Question 19

During prophase, assembly of spindle microtubules begins in the ___________; it replicates, forming two XXXXXX that migrate to opposite ends of the cell, as spindle microtubules grow out from them

Answer 19

centrosome

Question 20

What happens in ANAPHASE

Answer 20

sister chromatids separate and move along the kinetochore microtubules toward opposite ends of the cell
The microtubules shorten by depolymerizing at their kinetochore ends

Question 21

In animal cells, cytokinesis occurs by a process known as cleavage, forming a

Answer 21

cleavage form

Question 22

In plant cells, a _____ _____ forms during cytokinesis

Answer 22

cell plate

Question 23

The sequential events of the cell cycle are directed by a distinct____ ______ _____, which is similar to a clock; regulated by both internal and external controls. clock has specific checkpoints where the cell cycle stops until a go-ahead signal is received

Answer 23

cell cycle control system

Question 24

The checkpoints are

Answer 24

G1, G2, & M

Question 25

checkpoint seems to be the most important one | If a cell receives a go-ahead signal at the G1 checkpoint, it will usually complete the S, G2, and M phases and divide

Answer 25

G1

Question 26

If the cell does not receive the go-ahead signal, it will exit the cycle, switching into a nondividing state called the

Answer 26

G0 phase

Question 27

Type of cells do not respond normally to the body’s control mechanisms

Answer 27

cancer cells

Question 28

Cancer cells may not need growth factors to grow and divide:

Answer 28

They may make their own growth factor They may convey a growth factor’s signal without the presence of the growth factor They may have an abnormal cell cycle control system

Question 29

A normal cell is converted to a cancerous cell by a process called

Answer 29

transformation

Question 30

masses of abnormal cells within otherwise normal tissue

Answer 30

tumors

Question 31

If abnormal cells remain at the original site, the lump is called a

Answer 31

benign tumor

Question 32

invade surrounding tissues and can metastasize, exporting cancer cells to other parts of the body

Answer 32

malignant tumor