all cells arise from other cells - 2

Question 1

4 stages of cell cycle

Answer 1

mitosis, gap phase 1, synthesis, gap phase 2

Question 2

structure of chromosomes

Answer 2

2 strands called sister chromatids joined in the middle by a centromere

Question 3

4 stages of mitosis in order

Answer 3

prophase
metaphase
anaphase
telophase

Question 4

what happens in prophase

Answer 4

chromosomes condense and get shorter and fatter
centrioles start moving to opposite ends to cell
nuclear envelope breaks down

Question 5

what’s happens in metaphase

Answer 5

chromosomes line up along the middle of the cell and become attached to the spindle by their centromere

Question 6

what happens in anaphase

Answer 6

centromere divides
spindles contract pulling the chromatids to opposite poles

Question 7

what happens in telophase

Answer 7

chromatids uncoil and become long and thin again turning into chromosomes
nuclear envelope forms
cytoplasm divides, cytokinesis, and two daughter cells are formed

Question 8

what is cancer

Answer 8

uncontrolled cell division

Question 9

what do cancer treatments aim to do

Answer 9

control the rate of cell division in tumour cells by distrusting the cell cycle

Question 10

what practical is used in this side topic

Answer 10

root tip squash

Question 11

preparing a root tip cell squash (8)

Answer 11

1. 1M hydrochloric acid to a boiling tube in a water bath at 60degrees
2. use a scalpel to cut 1cm from the tip of a root
3. transfer root tip to boiling tube and incubate for 5 mins
4. use a pipet to rinse well with cold water and dry the tip
5. place on a microscope slide and cut 2mm from the end of the tip
6. use a mounted needle to spread out cells thinly
7. add a few drops of stain
8. place a cover slip and press down

Question 12

how to calculate the mitotic index

Answer 12

number of cells with visible chromosomes/ total number of cells observed

Question 13

calculating the actual size of cells

Answer 13

size of image / magnification