B4-using food and controlling growth

Question 1

what’s cellular respiration?

Answer 1

-a series of chemical reactions.
-reaction makes ATP.
-a cell that isn’t carrying out this is a dead cell.
-exotbermic reaction.

Question 2

what’s ATP?

Answer 2

-breaks down carbs, proteins and lipids.
-essential for life.
-muscle contraction.
-active transport.
-contains 3 phosphate groups. (made from ADP and phosphate ions).

Question 3

where do reactions mainly take place?

Answer 3

-inside the mitochondria which is found in the cytoplasm.

Question 4

what’s the difference between aerobic respiration and anaerobic respiration?

Answer 4

-aerobic needs oxygen.
-anaerobic respiration doesn’t need oxygen.

Question 5

what is lactic acid?

Answer 5

-a toxin produced after the use of anaerobic respiration due to lack ATP.
-when it builds up in the muscle, it makes them feel tired and painful.
-glucose->latic acid

Question 6

what does anaerobic respiration make in plants?

Answer 6

ethanol and carbon dioxide.
glucose->ethanol + carbon dioxide

Question 7

what happens when a seed starts the germinate?

Answer 7

there’s little oxygen available to the cells but with anaerobic respiration they can still release ATP.
(also happens in waterlogged soil)

Question 8

what is fermentation?

Answer 8

-when yeast cells carry out anaerobic respiration.
-can produce bioethanol (fuel).

Question 9

what is the equation for the rate of change in volume?

Answer 9

change in volume
————————————
the time taken for change

Question 10

what are the 2 phases of the cell cycle?

Answer 10

-interphase.
-mitosis.

Question 11

what’s the interphase of a cell?

Answer 11

when cells grow larger, organelles are copied and each chromosome is copied.

Question 12

how does mitosis occur?

Answer 12

-when chromosomes copies separate, the nucleus divides and then the cells divides into two.
-if it continues it can form a tumour.

Question 13

when does sexual reproduction in plants happen?

Answer 13

when pollen grains from an anther is transferred to a stigma.

Question 14

how are gametes made?

Answer 14

-made through meiosis.
-this ensures that gametes end up with half the number of chromosomes of body cells.
-first division separates the copied chromosomes.
-second division separates the copies of the 23.
-this leaves half the number of chromosomes in each daughter cell.

Question 15

what is the difference between meiosis and mitosis?

Answer 15

meiosis:
-for sexual reproduction.
-1-4 cells.
-genetic variation.
mitosis:
-for growth and repair.
-1-2 cells.

Question 16

what’s are embryonic stems cells?

Answer 16

specialised cells that can turn into any type of cell, really helpful.

Question 17

what’s a differentiate?

Answer 17

when stem cells become specialised into any cell after 8 weeks.

Question 18

what’s are adult stem cells?

Answer 18

-specialised
-less useful

Question 19

what do plant stems cells do?

Answer 19

-stem grows taller.
-roots grow longer.
-to hold themselves upright.
-have meristems.

Question 20

what are meristem cells?

Answer 20

-dividing cells in plants.
-increase girth.
-allowing plant to grown new xylem/phloem tubes and organs (leaves).

Question 21

what’s phototropism?

Answer 21

a plants response to light.

Question 22

what’s gravitropism?

Answer 22

-a plants response to gravity.
-allows plant to get enough light for photosynthesis.
-helps plant find minerals and water.

Question 23

what’s auxin?

Answer 23

-moves down the stem.
-builds up on the shaded side of the shoot.
-makes cells grow faster here.
-controls response to light and can stimulate plant tissues to grow roots.

Question 24

what are gibberellins?

Answer 24

-a group of hormones responsible for making seeds germinate and making plants produce flowers.
-adding this to brewers can increase the production of amylase and speed the production of maltose.

Question 25

what does ethene do in plants?

Answer 25

-causes the ripening of fruit and dropping of leaves.
-produced when plant is damaged or lacks water or is cold.
-helps grow plants commercially.

Question 26

when is stem cell treatment needed?

Answer 26

-spinal cord and brain damage.
-blood disorders.
-diabetes.

Question 27

what are the risks of stem cell treatments?

Answer 27

-infections, from operation or infected stem cell.
-tumours, uncontrollable cell division.
-organ damage.
-immune rejection.
-graft vs host disease.

Question 28

how are adult stem cells useful?

Answer 28

they only differentiate into a small number of cell types.

Question 29

why are embryonic stem cells useful?

Answer 29

they can differentiate into any type of cell making them more useful for medicine and research.

Question 30

when is stem cell therapy used?

Answer 30

-for very serious, fatal diseases where there’s no other therapy available.
-therefore: patients should know risks.