Explanation:
Haemoglobin is a globular protein which is responsible for transporting oxygen around the body (Choice A). Choice B is incorrect as collagen is a fibrous protein. Choice C is incorrect as haemoglobin is not a fibrous protein and does not provide structural support. Choice D is incorrect as collagen does not transport oxygen.

Explanation​:
The graph shows an overall positive correlation, as maternal age increases, the incidence of non-disjunction increases (Choice A). Choice B is incorrect because there is a positive correlation not a negative correlation. Choice C is incorrect because there is a correlation. Choice D is incorrect because non-disjunction does occur below 35 years, but the incidence is lower when compared to above 35 years.

Explanation​:
Choice B is not true. Not all genes are expressed in each cell. Only the necessary genes are expressed based on the specialised function of the cell. All other statements are true.

Explanation​:
Choices B, C and D are incorrect because as the trees get darker, the camouflage of the peppered moth will be less effective, meaning it is more visible to predators and therefore more likely to be eaten.

Explanation​:
The nuclear envelope is the membrane that separates the nucleus from the cytoplasm. For mitosis to proceed it must be broken down in the first stage of mitosis which is prophase so that the spindle fibres are able to attach to the centromeres. Choice A is correct.

Metaphase (Choice B), Anaphase (Choice C) and Telophase (Choice D) all follow Prophase (Choice A) in the sequence of mitosis and do not involve the breakdown of the nuclear envelope.

Explanation​:
Choice A is incorrect because urea is reabsorbed.

Choice B is correct because all glucose is reabsorbed by the proximal tubule, none is reabsorbed by the distal convoluted tubule.

Choice C is incorrect because water is reabsorbed by the distal convoluted tubule.

Choice D is incorrect because Na+ ions are reabsorbed by the distal convoluted tubule.

Explanation​:
Choice C is correct because the transfer of seeds away from the parent plant is dispersal. Choice A is incorrect because the fusion of a male and female gamete is fertilization. Choice B is incorrect because the transfer of pollen from an anther to a stigma is pollination. Choice D is incorrect because pollen transfer involves the movement of pollen, not seeds.

Explanation​:
Choice A is correct because meiosis happens in the anther and ovule of flowers, it does not happen in the cells of the shoot apex. Choice B, Choice C and Choice D are incorrect because mitosis and cell elongation happen in the shoot apex to produce new cells and allow for primary growth (plant lengthening).

Explanation:
Choice A is correct because in both selective breeding and natural selection, favourable characteristics are “selected”, by either the environment (natural selection) or humans (selective breeding). Choice B is incorrect because natural selection doesn’t increase variation, it influences the proportion of existing variants. Choices C and D are incorrect because natural selection is not controlled by humans and does not contribute to the domestication of animals.

Explanation:
Both oogenesis and spermatogenesis involve mitosis, increase in cell size (cell growth), two meiotic divisions and differentiation. Choice A is correct.

Choice B is incorrect as it includes both apoptosis (cell death) and decrease in size, which does not occur in either process. Choice C is incorrect as binary fission occurs in prokaryotic cells and the generation of a polar body only occurs in oogenesis. Choice D is incorrect as budding only occurs in fungi, and fertilization (when mature sperm and egg cells fuse) occurs after both oogenesis and spermatogenesis.

Explanation:
Choices B, C and D are incorrect, as the gene pool consists of all the genes and alleles in an interbreeding population.

Explanation:
Mitosis forms two genetically identical daughter cells with the same number of diploid chromosomes as the parent cell.

18 (Choice B) is incorrect as it is the haploid number of chromosomes. 72 (Choice C) is incorrect as it is twice the diploid number of chromosomes. 9 (Choice D) is incorrect as it is a quarter of the diploid number and an odd number.

Explanation​:
The fossil record provides evidence of evolution, as the sequence in which fossils appear matches the sequence that they would be expected to evolve. Homologous structures provide evidence of evolution as they provide evidence that organisms shared a common ancestor. Speciation provides evidence of evolution as when populations become reproductively isolated, then natural selection can act differently on those populations, resulting in the formation of new species. Choice C is correct. Choices A and D are incorrect as the organisms becoming more complex does not necessarily correlate with evolution. Choice B is incorrect, as the increasing size of organisms does not necessarily correlate with evolution.

Explanation​:
Photosynthesis (Choice B) is the process by which carbon dioxide in the air is converted to carbon compounds in green plants.

Respiration releases carbon dioxide (Choice A), and decomposition by decomposers (Choice C) also releases carbon dioxide. Transpiration is the process by which water is drawn up the stem of a plant to the leaves where it evaporates (Choice D) and is not involved directly in the carbon cycle.

Explanation​:
Choice B is correct because pollination is the transfer of pollen from an anther to a stigma. Choice A is incorrect because the fusion of a male and female gamete is fertilization. Choice C is incorrect because the transfer of seeds away from the parent plant is dispersal. Choice D is incorrect because pollination can occur without a pollinator. Some plants are wind-pollinated.

Explanation​:
Choice B is correct because a meristem is a part of a plant with undifferentiated cells that undergo cell division. Choice A is incorrect because meristems do not have differentiated cells that undergo cell division. Choice C is incorrect because a meristem is not defined as a region of a flower. Choice D is incorrect because cell division in a meristem is not influenced by day length.

Active transport (Choice A) requires energy expenditure. Facilitated diffusion is a passive form of transport but active transport requires energy (Choice B). Facilitated diffusion (Choice D) does not require energy expenditure but this answer choice does not include osmosis.

Explanation​:
Telophase is the last phase of mitosis and does not cause mutations (Choice C). Single base substitutions cause a change in the base sequence of DNA, which is a mutation (Choice A). Carcinogens (Choice B) and high energy radiation (Choice D) are mutagens which means they can cause changes in the base sequence of DNA.

Explanation​:
Choice D is correct because there are four chromosomes, and each chromosome is composed of sister chromatids. Choice A and choice C are incorrect because, in metaphase, chromosomes are lined up on the equator. Choice B is incorrect because, during anaphase II, chromosomes are being pulled apart and towards opposite poles.

Explanation​:
Early in pregnancy, a human embryo secretes the hormone hCG, human chorionic gonadotrophin. This hormone maintains the corpus luteum in the ovary so that it secretes progesterone, which helps prepare the lining of the uterus for the implantation of the embryo.

LH (Choice A) and FSH (Choice D) are released by the pituitary gland, not the embryo. Oestradiol (Choice B) is released by the ovaries, not the embryo.

Explanation:
Choice A is correct because the medulla is the inner region of the kidney.

Choice B is incorrect because the outer region of the kidney is the cortex.

Choice C is incorrect because it is the renal artery.

Choice D is incorrect because it is the ureter.

Explanation​:
Choice B is correct because human males have one X chromosome and one Y chromosome. Choice A shows the sex chromosomes of a female. Choice D only shows the Y chromosome, which is incorrect because males have an X and a Y chromosome. Choice D only shows the X chromosome, which is incorrect because males have an X and a Y chromosome.

Explanation​:
mRNA, also known as messenger RNA, carries the genetic information needed for protein synthesis (Choice B).

Ribosomal RNA is found in ribosomes. This RNA contributes to the structure of the ribosome and does not code for proteins (Choice A).

ATP (Choice C) is a molecule made out of a nucleotide (adenosine tri-phosphate), while nucleic acid is made out of many nucleotides.

tRNA (Choice D), also known as transfer RNA, brings amino acids to the ribosomes and does not code for proteins.

Explanation:
Choice A is correct because pollen is produced by the anther and the ovum (plural: ova) is produced by the ovule, found inside the ovary. Choice B is incorrect because the stigma is where pollen lands. Choice C is incorrect because the filament supports the anther and does not produce pollen. Choice D is incorrect because the filament supports the anther and the style is the part of the flower that the pollen passes through.

Explanation:
Choice A is correct because when there are fewer copies of a given strand of mRNA in the cytoplasm, ribosomes have fewer copies to bind to and thus the rate polypeptides are synthesised based on this strand will decrease, not increase (Choice B).

Choices C and D are incorrect because if the rate mRNA is degraded decreases, there will be more copies of this strand of mRNA resulting in an increase in the rate ribosomes bind to these strands and synthesise polypeptides.