six mark answers

Any six from:

• dip/soak a disc in an antibiotic or both discs

• set discs on agar

• incubate/more than 1 day/leave for 24 hrs or more

• at 25°C/less than 25°C/about 25°C

• seal/use sellotape/do not reopen

• autoclave/sterilise after/safe disposal/wipe benches with alcohol/disinfectant

(before or after)

• A has a bigger clear area

• A kills more bacteria/prevents more growth/more bacteria destroyed

Any five from:

• warmer/temperature higher in 4;

• windier/the fan is on in 4;

• more evaporation (inside the air spaces or cells in leaf);

• more diffusion (inside the air spaces or cells in leaf);

• higher rate of transpiration/more transpiration

• through the stomata

• maintain diffusion gradient

Cholesterol laid down in walls

• Of coronary arteries

• Reducing blood fl ow

• Less glucose/oxygen available

• For respiration

• Heart muscle cells die

• So heart can’t contract

Day 1–5 lining breaks down/wall breaks down

• Day 1–5 hormone levels low

• Hormone level increases after day 5 or 6

• Hormone reaches a peak at day 11, 12, 13 or just before ovulation

• The hormone levels drop after ovulation

• On day 14 an egg is released from the ovary

• Oestrogen made in ovaries

• After day 14 egg moves down oviduct/Fallopian tubes

• Uterus lining built up after 5/6 to day 16

Record the mass of the apparatus containing the plant initially/at start

• Leave for a given time

• Record mass at end/change in mass

• Divide change in mass by time (to work out rate)

• A named variable constant – temperature/humidity/wind speed/same

(type/species) plant

• Repeat with reduced surface area/remove leaves/use plant with less/

larger/smaller leaves

• Repeat for reliability/to obtain averages

• Keep another variable constant – temperature/humidity/wind speed/

light/same type/species of plant

Gene for insulin removed (from human chromosome)

• Plasmid removed from bacterium

• Plasmid cut open

• Insulin gene inserted

• Plasmid reinserted into bacterium

• Bacteria multiply/clone/mitosis