I thought it'd be useful to provide an unofficial mark scheme. Most of these will initially be off my memory so I don't remember the question numbers, sorry.
First question: (Labelling of the neurone)
From top to bottom:
Node of Ranvier
ii) Two types of effectors
iii) Where would region X be found in a spinal cord?
iv) Which root would Y be found?
Ventral(As it's a motor neurone)
Kidney micrograph question:
There was definately a glomerulus and bowman's capsule present, not sure about the third one.
When asked which section of the kidney it is from, it's the cortex.
In micrograph B, those seen are loop of henle (ascending and descending) and collecting duct
Nitrogen cycle "filling in the gaps"
Pseudomonas decomposes the nitrates from plants into ammonia
Nitrosomonas convert ammonia into nitrites
Nitrobacter decompose the waste products of this bacteria to nitrates
Rhizobium found in root nodules
Azotobacter found free living in soil
Why is the population growth less in lactate than in glucose?
Possibly because an enzyme is required to split lactate into its' monosaccharides
Possibly because it has less Carbons
Describe the graph of Q
General increase, from 0-30 minutes it enters lag phase, synthesising of enzymes
30-210 enters log phase where it generally increases(population)
The dip could be due to intraspecific competition, or where nutrients ran out and were re-added
Enters stationary phase after 210 minutes, death rate = birth rate
Labelling of ATP:
What is the name of the reaction produces ATP?
What is the name of the pentose sugar?
What is the name of the base?
Describe how energy is released from ATP
High energy phosphate bonds hydrolyses. Catalysed by the enzyme ATPase. Releases 30 kJmol-1 of energy
Photosynthetic alga question:
Describe and explain the distribution of bacteria
The bacteria are found mainly in blue and red wavelength sections. Photosynthesis releases oxygen and takes place best with red and blue wavelengths of light. In these sections more oxygen will be present and so the oxygen seeking bacteria will be most likely to stay near these areas.
What would happen if the prism was removed?
The bacteria would align in the centre point (Where the light would shine)
Describe the process by which oxygen is released by the alga?
Non cyclic photophosphorylation. PSI loses 2 electrons which are replaced by 2 electrons from PSII. Water undergoes photolysis which products are oxygen, electrons and hydrogen. The electrons and hydrogen are used to reduce NADP and the oxygen is evolved - thus producing oxygen. (Worth 6 marks so more points would be needed)
a) (I didn't do this so don't remember it)
b) i) Describe the important of the cell membrane in nerve transmission:
Explain about there being pumps and channels in the membrane and when an impulse arrives the Na+ channels open and the Na+ ions rush in by diffusion, depolarising the membrane. Then K+ channels open and this causes repolarisation. There is a refactory period where the channels and pumps can not work which ensures unidirectionality. (Requires more points as it was 7 marks)
ii) And in nerve transmission across a synapse:
Describe how the impulse causes Ca2+ to move into the synaptic bulb and this causes the synaptic vesicles to fuse with the presynaptic membrane, secreting their neurotransmitter by exocytosis. This diffuses across the synaptic cleft and the protein receptors in the post synaptic membrane detect them, which causes the Na+ channels in the post synaptic neurone to open, and Na+ diffuses in, causing depolarisation.
If you know any more questions/want to know answers let me know and I'll try and remember what I put.
P.S. These are what I wrote and asked my teacher and so they may or may not be correct
(Original post by XO*)
It was putrefaction not dentrification. So the answer was saprobiotic bacteria.
Pretty sure it was dorsal root.
I'm guessing decomposers would be alright as well? Had to decide between putrefaction and decomposers, so put the substance that does it as the rest of the passage was mostly talking about the substances/enzymes. I am guessing they would accept but putrefaction and decomposers though, as it was not made clear whether to put the name of the process, or what actually does it?