Extras

Question 1

4 factors that affect diffusion

Answer 1

Diffusion distance- smaller = faster

Temperature - more KE = move faster

Conc gradient- steeper = faster

SA: V - larger means faster

Question 2

whats happens if a plant cell is placed in a strong sugar solution

Answer 2

If a plant cell is placed into a strong sugar solution (with a lower water potential than the cell),

• it will lose water by osmosis
• It becomes flaccid or plasmolyzed (shriveled up)

Question 3

function of mouth + LI

Answer 3

mechanical dige- teeth chew food into smaller pieces + tongue rolls food into bolus

water is absorbed from the colon to produce feces

Question 4

peristalisis

Answer 4

• Circular muscles contract = reduce the diameter of SI

- Longitudinal muscles contract = reduce the length of SI

Question 5

stages of food breakdown

Answer 5

ingestion - eating

mechanical digestion- breakup of food to increase SA

chem diges-enzymes breakdown large insoluble molecules –> small soluble

assimilation- movement of digested food molecules —> cells of body

absorption- movement of small food molecules—> blood

Egestion – pooping

Question 6

enzymes

Answer 6

• low temp —> low KE —> few collisions —> below optimum
• optimal/ high temp —> high KE —> high collisions—> past optimum
• past optimal temp —> enzyme denatured —> active site changed = no ESC

Question 7

Cons of excess sugar for health

Answer 7

• Sugar causes cavities as sugar provides energy + respiration for bacteria
• Excess amounts of sugar = type 2 diabetes as insulin resistant + obesity= excess calories/energy

Question 8

ways to improve experiment

Answer 8

• same mass of X
• same volume of X
• use control
• temp/pH
• gender/weight/fitness
• starting time/level

Question 9

describe how light rays are focused in normal vision

Answer 9

• light rays refracted by the lens/cornea

- light rays focused on retina

Question 10

bacteria cells

Answer 10

• flagellum
• no nucleus
• Meurin cell wall
• ribosomes
• cytoplasm

Question 11

role of FSH + oestrogen

Answer 11

• ova/egg matures in follicle
• estrogen released
• repairs uterus lining

Question 12

role of LH + progesterone

Answer 12

• ovulation (day 14)
• egg released from ovary —> oviduct
• progesterone released
• maintains uterus lining + released by Corpus luetm
• breaks down only on day 28 (menstruation)

Question 13

role of placenta + amniotic fluid

Answer 13

• allows nutrients + oxygen
• to DIFFUSE
• from mother to fetus
• protect developing fetus
• cushions/shock absorber

Question 14

sperm cell adaptations

Answer 14

• acrosomes contain enzymes to penetrate egg
• haploid nucleus
• flagellum to swim/move
• lots of coiled mitochondria for energy to swim to egg

Question 15

Describe the role of the placenta in the development of the embryo.

Answer 15

• diffusion;
• glucose / oxygen;
• respiration / energy / ATP;
• vitamins / named vitamin /
• remove carbon dioxide / remove urea;

Question 16

describe population/community and habitat

Answer 16

• number of a species
• different species
• place where organism lived

Question 17

what do polythene tunnels provide

Answer 17

• a slight increase in temp
• enzymes work better —> more photosynthesis/respiration
• protection from pests

Question 18

why are artificial fertilizers added

Answer 18

• more mineral ions
• e.g nitrate for amino acids
• e.g magnesium for chlorophyll
• e.g phospshurous for dna/atp

Question 19

steps for yogurt production (6 steps)

Answer 19

• pasteurization at 85ºC-95ºC for 15-30 mins
• homogenization (emulsification of fat droplets)
• cooled at 40ºC-45ºC + inoculated w lactobacillus
• incubated w lactobacillus converting lactose—>lactic acid
• thickened yogurt cooled to 5ºC
• flavoring + coloring added