Bio Ch 8

Question 1

Telomeres

Answer 1

sections of noncoding, repetitive DNA that acts as a protective cap on the tip of each chromosome
- eventually run out of telomeres
- results in death of cells
- association between length of telomeres and aging
- newborn baby has very long telomeres
—your cells aren’t immortal; mortality to cells

Question 2

Hutchinson-Gilford progeria

Answer 2

Telomeres are shorter than normal. Begin to appear aged early after birth. Rarely live past age 13

Question 3

Some cells rebuild their telomeres

Answer 3

-single-celled eukaryotes
-cells that produce gametes

Question 4

Cancer

Answer 4

telomere rebuilding and uncontrolled cell division

Question 5

Normal cell division is necessary

Answer 5

to maintain most organisms

Question 6

In eukaryotic cells, telomeres…

Answer 6

keep track of cell divisions by shortening every time the cell divides

Question 7

If the telomere becomes too short

Answer 7

= additional cell divisions after will cause loss of essential DNA and cause cell death

Question 8

How many chromosomes in sperm/egg cell

Answer 8

sperm cell= 23 unpaired chromosomes
egg cell= 23 unpaired chromosomes
Total= 46 chromosomes in fertilized egg (because they combine)

Question 9

Prokaryotic cells

Answer 9

single circular chromosome attached to cell membrane

Question 10

Eukaryotic cells contain

Answer 10

linear chromosomes within a nucleus

Question 11

Binary Fission

Answer 11

-replication: cell creates a duplicate of each chromosome
- parent cell divides to create 2 daughter cells
—–cell elongates and pinches into 2
-Prokaryotic cell division= Binary Fission
-Asexual Reproduction

Question 12

Interphase

Answer 12

Gap 1: cells primary growth phase. Normal cellular functions take place
S phase: preps for cell division. Replication occurs here
Gap 2: 2nd period of growth

G0: some cells never divide
ex: the brain (doesn’t make new cells)
- resting phase outside of cell cycle
-cells may stay here for days or years

Question 13

After Interphase comes

Answer 13

Mitosis: parent cell’s nucleus with it’s duplicated chromosomes divide
Cytokinesis: cytoplasm divides into 2 identical daughter cells

Question 14

Cell Cycle Control System

Answer 14

3 primary checkpoints that regulate cell cycle in eukaryotes
G1/S Checkpoint
G2/M Checkpoint
Spindle Assembly Checkpoint

Question 15

G1/S Checkpoint

Answer 15

is DNA damaged?
does cell have sufficient nutrients?
-make past this; DNA then replicates

Question 16

G2/M Checkpoint

Answer 16

has DNA replicated properly?
-Make past this; cell divides

Question 17

Spindle Assembly Checkpoint

Answer 17

Are spindle fibers properly built and attached?

Question 18

If Cells don’t go through checkpoints

Answer 18

it could cause a mutation

Question 19

DNA Replication occurs in

Answer 19

the nucleus
-also means chromosomes are copied

Question 20

Some mutations don’t cause terrible things
Some show up in certain populations

Answer 20

ex: the Amish
- stays in Amish community