Mitosis L13

Question 1

How much RNA do viruses have?

Answer 1

Double/sing stranded DNA/RNA

Question 2

Prokaryotic bacteria have:

Answer 2

Circular, singly copy, naked double stranded DNA

Question 3

Eukaryotes have:

Answer 3

linear, ≥ single copy, histone bound DNA and a sexual cycle

Question 4

What is a karyotype?

Answer 4

A carefully ordered visual representation of our chromosomes

Question 5

How is a karyotype obtained?

Answer 5

Sample of cells treated with mitogen to begin cell division so the chromosomes become visible

Then treated with colchicine to stop mitosis + stained to see them

Question 6

Why do we need cell division?

Answer 6

For growth and repair + renewal of tissues

Question 7

Phases of the cell cycle

Answer 7

Interphase
Mitotic (M) phase

Question 8

Interphase

Answer 8

G1 phase - metabolic activity + growth
S phase - metabolic activity + growth, synthesis of DNA to have replicated DNA
G2 phase - metabolic activity + growth, prep for cell division

Question 9

Mitotic phase

Answer 9

Mitosis

Cytokinesis

Question 10

Mitosis

Answer 10

Please pass me a Table

Prophase
Prometaphase
Metaphase
Anaphase
Telophase

Question 11

Prophase

Answer 11

G2 of interphase

The chromosomes double but are not condensed. Centrosomes prepare with the centriole pairs
Enzymes needed for division are produced

PROPHASE
*Asters have early mitotic spindles forming between them
*Duplicated chromosomes condense to form homologous pairs of sister chromatids

Question 12

Prometaphase

Answer 12

*Nuclear envelope disappears and fragments can be seen
*Mitotic spindles move to opposite ends of the cell
*Mitotic spindles extend kinetichore and non-kinetichore microtubules
- Kinetichore microtubules attach to centromeres of sister chromatids via kinetichores
- non-kinetichore microtubules attach to other non-kinetichore microtubules

Question 13

Metaphase

Answer 13

The centromeres of the sister chromatids line up at the metaphase plate i.e the equator

Question 14

Anaphase

Answer 14

The kinetichore microtubules shrink and seperate the chromatids at the centromeres

The non-kinetichore microtubules lengthen to push the poles apart

Question 15

Telophase + cytokinesis

Answer 15

*Spindles disappear - microtubules break down into tubular monomers to form the cytoskeleton of the new cell
*Nucleolus forms
*Nuclear membrane forms
*Cleavage furrow and cytoplasm forms for cytokinesis

Question 16

During which phase do organelles replicate?

Answer 16

G1 phase

Question 17

How do plant cells divide?

Answer 17

Form a cell plate through the extension of vesicles forming a membrane partition

Question 18

G1S

Answer 18

1º Checkpt that determines if the cell should continue division or stop, corrects any error prior

External signals and growth factors can influence cell cycle and affect progress/before checkpt

Question 19

G2M

Answer 19

Makes sure cell successfully completed interphase before mitosis

Question 20

Spindle checkpt

Answer 20

Makes sure spindle is attatched for anaphase

Question 21

Factors that contribute to cell cycle

Answer 21

*Growth factors
*Size of cell
*Nutritional state

Question 22

How long for plant/animal cell to divide?

Answer 22

10-20 hrs