AQA Biology unit 4

i had so little time for this paper!
I am really going to have to work hard for unit 5. But can only really start friday and have CHEM5 on the following monday!
stresssssssssedd

These are all the answers I've done so far-

1a- Nitrogen gas is usual substrate- name product

AMMONIA

1b- Nitogenases also catalyses other sub explain what this suggests about shape of other sub...

The other subs can for EZ complexes and so is complemenary to the active site and consequently are similar in shape to the Nitrogen molecule

1ci- Two advantages of the very high rate of aerobic respiration.

1) Lots of energy for protein/enzyme synthesis.
2) Provides anaerobic conditions for enzymes to work

1cii- Explain why they'd grow more slowly.

As they'd need to synthesize the enzymes and then fix the nitrogen which takes longer than just absorbing it out of fertiliser.

2a- Size of pop
59(60?)

2bi- Result not reliable in June

Because after initial capture, young may leave nests and join adult population, increasing the population between samples, making the technique unrelaible.

2bii- Result not reliable in March

Birds will stick to their territories making it difficult to obtain a random sample. It is likely that birds from one sample area will stay there and be recaptured during the next sample, decreasing reliability due to lack of randomness.

2c- You can use base sequence for mark release recapture explain why
Base sequence unique to each whale, so can be used as a marker for that whale.

Haven't done the rest yet >_<.

sis u do te exam do?...i gt similar answers..cldu u do te rest for me..i'm sloghtly wirred coz i left a whole question out!!

there definitely was square rooting. It gave you the frequency of the phenotype, not the genotype.

frequency of phenotype=q^2
frequency of genotype=q

could you elaborate on this? sorry for being such a pain.

i left te whole of question 7 out, any1 knw how much tat question was worth>?

15 marks? its the tamil scientist one? that was 15 marks...

No I did not do the exam. I will finish it later.

could you post the rest of the paper up please.i really would like to try to answer question 7 again, as i have a gut feeling that a similar question will come up again in the unit 5 exam on friday.

For the Co2 changing, the key word was 24hours. It was do with respirationhotosynthesis, you had to talk about how they respire less at day, more at night, photosynthesise more at day and less at night. Hence Co2 fluctuates. No way was it to do with soil and temperature that's just bull.

me too inie, in jan they lowered te bounderies, hope tey do tat again, tey had tis big fiasco in jan, coz lost of te sools n all complained sayin te paperwas just out of tis world, so hopefully tey lower it tis tim!!

Is the respiration rate not constant throughout the day? I didn't think respiration was less in day

nah respiration is less in the day because it's rate of photosynthesis is so high so it takes up more Co2. At night stomata close, so it needs to respire

It is. Respiration is constant, unless it's warmer during the day or colder during the night, but there was no mention of temperature.