By Conrad, Advait and Ayaz - credits to JackCollard. The items in bold are certain, the rest is correct but not certain.
1.a) Vacuole, cell wall, chloroplasts. (3)
1.b) Receptor cell (sensory), relay Neurone, motor neurone, Effector organ/muscle fibre. (4)
1.c) Gap between neurones = synapse. (1)
1.d) 0.0075 seconds. (2)
2.a.i) Both beef cattle and fish farming has increased. Fish farming experienced an exponential growth from 1980s onwards whilst the increase in beef cattle had fluctuations. Originally the beef cattle at 20m tonnes was greater than fish farming (1m tonnes) but by 2011 the fish farming produce exceeded that of beef cattle. (3)
2.a.ii) (Calculation in 2020 fish production will be 6 times 1990 rate - how many fish?) 13 million tonnes in 1990 x 6 = 78m tonnes in 2020. (2)
2.b) Fish proteins broken down by protease enzyme pepsin - proteins into peptides. The HCl stomach acid (pH 2) provides optimal pH for the enzyme. The stomach muscles churn the food, increasing surface area for enzymes to act upon. The acid also kills any microbes on the food to prevent sickness/disease. (4)
2.c) (Table of structures and function) - haemoglobin transports oxygen in blood around body to cells, insulin made in pancreas, amylase, antibodies made by Lymphocytes. (4)
3.a) E.g combustion reaction in cars releasing CO2. (1)
3.b) E.g carbon monoxide. (1)
3.c) Percentage decrease of 16.0 percent. (2)
4.a) Methane decreases with a range of 2.5 starting at 4.6 million tonnes in 1990 decreasing to 2.1 million tonnes in 2010. At the beginning the drop was greatest, from 2005-2010 the drop was smallest at 0.1 million tonnes. (2)
4.b) Reasons for decrease in in CO2 emissions: decrease in the use of fossil fuels being burnt in combustion reactions, more catalytic converters in cars, increase in recycling/less wasting, more energy efficient/renewable resources used. This kind of stuff. (3)
5.) Decrease in the growth/thickness of greenhouse blanket hence greenhouse effect hence global warming. Ice caps melt at slower rate, reducing risk of xtinction of polar bears. Less carbon monoxide emitted, hence decrease in poisonous gases in atmosphere that can kill people. Decrease in emissions of SO2 and N2O2 will result in less acid rain hence less killing of organisms in soil, trees, aquatic plants and fish - forgot some other things I put down. (5)
6. CORMS method (Describe an Experiment) (6)
7.a) Graph. (6)
7.b) Description of graph. Increase in stomal pores = increase in rate of transpiration but not proportional. At still air, the rate of transpiration caps at 50 units whereas in moving air, the overall rate of transpiration is higher and the rate of transpiration continues past 164 units. (2)
8.a) Thistle. (1)
8.b) The bird (name). (1)
8.c) A= Pupil B= Iris (2)
8.d) Sclera, optic nerve, lens. (3)
9. [Fill in the gap question] Explant, [genetically] identical, sterile, micro-organisms (bacteria), sterile growth [medium], starch, chlorophyll, nitrates, large, any. (10)
10.a) A population is the number of same species in a certain area in a certain time. (1)
10.b) Describe the changes in populations of the snail colours with reference to natural selection: mutation, variation, gene, DNA, survival of the fittest, reproduction passes alleles for certain gene for colour, black shelled ones die out/extinct. Occurs over generations. (5)
11.a) 136.1 BPM. (2)
11.b) Thomas was the anomaly. (1)
11.c) Heart rate slightly increases just before exercise due to adrenaline being secreted from the adrenal glands causing heart rate to increase - pumps blood harder and faster. Prepares body for fight or flight response (could mention excitement causes the adrenaline). (2)
d) (Two controlled variables) [mention two]:
Length of Exercise
Age of Children / bmi of children
Time measuring heart rate
Same temperature / time of day (2)
12. (Runners and Cyclists lower resting BPM Question) Adapted Red blood Cells Carry More Oxygen in oxyhemoglobin to body cells more efficiently for aerobic respiration. Heart muscles strengthen hence blood can be pumped with greater pressure and be maintained hence less heart beats needed to supply body cells with oxygen to respire = lower heart rate. (4)
13.a) Bacteria has cell wall, cytoplasm, plasmid, no nucleus. Fungi has cell wall, cytoplasm, nucleus, no plasmids. Protoctist has no cell wall, plasmids but have nuclei and cytoplasm. (4)
13.b) Virus. (1)
13.c) E.g Malaria. (1)
14.i) Oviduct/fallopian tube (1)
14.ii) Ovary (1)
14.iii) Uterus Lining (1)
14.iv) Vagina (1)
15.a) M at beginning of graph, O at the start of the surge of progesterone. (2)
15.b) Oestrogen causes the thickening or building up of the uterus lining, progesterone further builds up and maintains uterus lining, if egg cell not fertilised and corpus lute stops secreting progesterone, uterus lining breaks down in menstruation. (3)
16.a) (Question on Why is Sex off period not always a reliable method of contraception) - women menstrual cycles, whilst predictable can sometimes be different to what they are normally hence can be random and it is hard to tell when you have ovulated hence can result in accidental fertilisation of sperm and ovum during sexual intercourse. (2)
16.b) (What does Oestrogen do in puberty?) - outlined points:
Widening of hips/pelvis
Voice box remains small
Follicles start maturing hence ovulation begins
Pubic hair
Breasts develop
Larger proportion of body mass converted into fat for nutrients (3)
16.c) (Which Parent determine babies Sex?). Father, as a sperm carry either an X or a Y set of chromosomes and because a women's chromosomes are always XX, the egg is always carrying a set of an 'X'chromosomes so the sperm can create an XX (female) or XY (Male) baby. (2)
16.d) (Differences Between Meiosis and Mitosis) [Mention].
Mitosis creates two daughter cells
Meiosis creates four daughter cells
Mitosis creates genetically identical cells
Meiosis creates Genetically different cells
Mitosis creates two new cells with 46 / a full set of chromosomes
Meiosis creates four new cells with 23 / half a set of chromosomes
Mitosis creates Diploid Cells Meiosis creates Haploid Cells (4)
Other questions:
Stomata:
For transport: Water being lost via transpiration hence more drawn up via transpiration pull due to capillarity and cohesion. More water absorbed into roots via osmosis. (Define definitions). (2)
For transpiration: Stomatal pores open increases surface area for diffusion of gases in and out of leaf. CO2 in for photosynthesis (reference concentrations in and outside leaf) and O2 and water vapour out during day time. (2)
Increasing wind on rate of transpiration: Wind blows the water vapour particles next to the leaf away (lost from transpiration) hence maintains a high concentration gradient hence increases the rate of transpiration. (3)