!! 4.1.2, Cell Division

Question 1

why is it important for the daughter cells, produced during mitosis, to have the same chromosomes as each other

through mitosis

Answer 1

important for processes that require identical cells to be produced

e.g the growth and repair of tissues and asexual reproduction

Question 2

what are the 3 stages of the cell cycle

Answer 2

initial growth stage

mitosis

cell divides

Question 3

what cycle do cells use to divide

Answer 3

cell cycle

Question 4

summary of what happens during the cell cycle

Answer 4

genetic material is doubled

then divided into two identical cells

Question 5

where are chromosomes housed in eukaryotic cells

Answer 5

in the nucleus

Question 6

how are chromosomes usually found in body cells

Answer 6

in pairs

and each carries a large number of genes

Question 7

what happens in the initial growth stage of the cell cycle

Answer 7

extra ribosomes, mitochondria and other sub-cellular structures are produced

the cell’s chromosomes (which are made of DNA) are replicated

now there are two sets of the cell’s chromosomes.

Question 8

what happens in the 2nd stage of the cell cycle (mitosis)

Answer 8

the two sets of chromosomes are pulled to opposite ends of the cell

then, the nucleus divides into two

Question 9

what happens in the final stage of the cell cycle

Answer 9

cell divides

and two identical cells are created by the division of the cytoplasm and cell membranes

Question 10

which processes involve the production of identical daughter cells

Answer 10

asexual reproduction

growth

repair

Question 11

what would you expect to happen to the reaction rate in yeast if you increase the temperature

Answer 11

rate of respiration would increase as temperature increases

above a certain temperature, the rate would start to decrease

eventually, the reaction stops because enzymes denature at high temperatures

Question 12

what are stem cells

Answer 12

undifferentiated stem cells that have not yet specialised to perform a specific function

Question 13

what are 2 places where stem cells can be found

Answer 13

Plant meristems

bone marrow

embryos

Question 14

where are stem cells found in plants

AMD what can they do

Answer 14

meristem tissue

and can differentiate into all types of plant cells throughout the life of the plant

allows plants to grow for their whole lives.

Question 15

what are human adult stem cells used to do

Answer 15

they are used to replace dying cells and damaged tissues

and can differentiate into fewer cell types than stem cells in embryos

Question 16

what do stem cells in embryos do

Answer 16

used to produce all of the cell types that will make up the organism

therefore can differentiate into most cell types

Question 17

3 uses of stem cells for medical, scientific and commercial purposes

Answer 17

stem cell treatments

plant clones

therapeutic cloning

Question 18

how can stem cells from plants be used

Answer 18

to quickly and cheaply produce cloned plants

could help to protect rare plant species from extinction

and create large populations of plants with special features

e.g disease resistance

Question 19

2 diseases that stem cell treatments may be able to cure

and how they work

Answer 19

stem cells may be able to replace damaged cells in the body

e.g stem cells may replace the damaged cells that cause diabetes or paralysis

Question 20

what is a risk of stem cell transplantation

Answer 20

viral infection

Question 21

why may some people object to stem cell treatments

Answer 21

the embryo could be a human being