Theme 2D Iheritance Of Dna

Question 1

What is the cell cycle

Answer 1

The process, where one cell grows and divides into two daughter cells

Question 2

What is the first step of the cell cycle

Answer 2

G1 (gap phase) where proteins, RNA, metabolites and anything other than DNA is synthesized

Question 3

What is the second step of the cell cycle

Answer 3

S phase Where DNA replication occurs

Question 4

What is the third phase of cell cycle

Answer 4

G2 phase

Question 5

What is the 4 step of cell cycle

Answer 5

M-phase where

mitosis: nuclear division (seperation of chromosome)

Cytokinesis: cell division (separation of cell into two daughter cells)

Occurs

Question 6

What is the last phase of the cel cycle

Answer 6

G0: resting phase or quienscence

(When cells stop dividing, no more telomeres)

Question 7

What phase of the cel cycle are most adult human cells in

Answer 7

G0 permanently (muscle or nerve cells)
Or semipermanently (liver cells reenter g1 during injury)

Question 8

What is cyclin dependent kinase

Answer 8

Enzyme that adds phosphate to protien substrate

Need to be activated in order to progress the cell cycle

Is bound to a regulatory cyclin subunit in each phase of cell cycle

Question 9

What are checkpoints during the cell cycle

Answer 9

They delay the cell cycle to allow completion of the events in each phase before moving onto the next phase

Question 10

What is the DNA damage checkpoint
Where does it occur

Answer 10

Makes sure dna is okay for replication
Happens between G1 and S phase

Question 11

What is the DNA replication checkpoint
Where does it happen

Answer 11

Checks if DNA is fully replicated before mitosis
Happens between G2 and M phase

Question 12

What is the mitotic spindle checkpoint
Where does it occur

Answer 12

Check if chromosome are aligned properly in metaphase
Happens before anaphase

Question 13

How is cancer caused in relation to cell division?

Answer 13

Caused by uncontrolled cell division, and altered expression of multiple genes due to mutations

Question 14

What mutated genes are in cancers

Answer 14

Onco genes and tumour suppressor genes

Question 15

What do ONCOGENES do

Answer 15

They are positive regulators of the cell cycle (gain of function) so they amplify the cell cycle turns, and they amplify the genes through cyclin D/E

Insensitive to inhibition

Question 16

What are tumour suppressor genes?

Answer 16

Negative regulators of the cell cycle (loss of function) including checkpoint jeans P 53 and RB. This causes no cell cycle stops, because the checkpoint genes aren’t functioning.

Question 17

What does n mean?

Answer 17

Haploid number of unique chromosomes

Question 18

What does 2n mean?

Answer 18

Diploid number of chromosome

Question 19

What are homologous chromosomes

Answer 19

Maternal and paternal pair of. Chromosomes.
One from mom one from dad

Question 20

Review slides 6 7 8 9

Question 21

Describe the cell cycle in prokaryotes

Answer 21

Replication starts at the origin, where the chromosome is attached to the cell membrane

Then the cell elongates so the replicated chromosomes can separate

The plasma membrane of the cell undergoes inward growth and creates a new cell wall.

Each chromosome goes into their own separated cell. This makes two daughter cells

Question 22

What is pre meiotic replication

Answer 22

Occurs in germ cells
Pre meiotic replication duplicates 4 chromatids to make 4 chromosome with 2 chromatids per chromosome

At the start of prophase 1, the chromosomes (homologous pairs) condense

Then synapsis occurs where non sister chromatids from each homologous pair, are attached together by the synaptonemal complex

Question 23

What is happening at the start of prophase 1 in meiosis

Answer 23

At the start of prophase 1, the chromosomes (homologous pairs) condense

Question 24

What is happening during synapsis in meiosis 1

Answer 24

Then synapsis occurs where each homologous pair, are attached together by the synaptonemal complex

Big red big blue
Small red small blue

Question 25

What happens during recombination in meiosis 1

Answer 25

The homologous chromosomes cross over sections of their non sister chromatids

The sections break and exchange equal non sister chromatids

Then the breakage is repaired, with 1/4 of each chromatid being exchanged

Question 26

What is reductional division in meiosis 1

Answer 26

The number of homologous pairs of chromosomes is changed from 2 in the parent cell to 1 in the daughter cells

Parent: red red blue blue
Daughter: blue blue
Daughter 2: red red