A: Unity and diversity
Describe nucleosome
Each nucleosome is composed of a little less than two turns of DNA wrapped around a set of eight proteins called histones
It describes the movement of the oxygen dissociation curve to the right of normal
Bohr shift
Give specific example of cyclic metabolism.
Glycolysis, the Krebs cycle and the Calvin cycle
Function of DNA primase
Synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template
Contrast lytic and lysogenic cycle
The lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell. The lysogenic cycle involves the incorporation of the viral genome into the host cell genome, infecting it from within
Give examples of globular and fibrous proteins.
Haemoglobin, immunoglobulin. Keratin, collagen, elastin
Carbon dioxide, NADH, FADH2, and ATP or GTP
What are consequences of mutations in proto-oncogenes
Convert them to oncogenes
Describe origin of eukaryotic cells by endosymbiosis
Evidence suggests that all eukaryotes evolved from a common unicellular ancestor that had a nucleus and reproduced sexually. Mitochondria and chloroplast then evolved by endosymbiosis.
Explain sodium-dependent glucose cotransporters as an example of indirect active transport
Cotransport is driven by active sodium extrusion by the basolateral sodium/potassium-ATPase, thus facilitating glucose uptake against an intracellular up-hill gradient
Chemical differences between transmembrane receptors and intracellular receptors
Intracellular receptors that located in the cytoplasm or nucleus of target cells bind lipid-soluble chemical messengers. Cell surface receptors are transmembrane proteins that bind water-soluble chemical messengers.
How would you determine isotonic concentration in osmosis graph?
X axis, y axis - 0
Describe "molecular clock"
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged.
How can you measure joint angles? (2)
Students should measure joint angles using computer analysis of images or a goniometer.
What are the reason for annual fluctuations of Keeling Curve?
The Keeling Curve is a plot that tracks the concentration of CO2 in the atmosphere since 1958. It shows a steady upward trend, with seasonal fluctuations due to natural processes like plant growth, photosynthesis.
Describe how evolution as a consequence of climate change
Example: changes in the fitness of colour variants of the tawny owl (Strix aluco) as a consequence of changes in snow cover.
Explain abrupt speciation in smartweeds by hybridization and polyploidy
Abrupt speciation in smartweeds (genus Polygonum) can occur through hybridization between two species, followed by polyploidy (doubling of chromosome number). This creates a new, fertile species that is reproductively isolated from both parent species, allowing instant speciation in one generation.
Explain relationship between dentition and the diet of omnivorous and herbivorous representative members of the family Hominidae
In Hominidae, herbivorous members (like gorillas) have larger molars and strong jaw muscles for grinding plant material, while omnivorous members (like humans) have a variety of teeth—incisors, canines, and molars—adapted for cutting, tearing, and grinding both animal and plant-based foods.
Give examples of effects of exogenous chemicals on synaptic transmission.
Neonicotinoids as an example of a pesticide that blocks synaptic transmission, and cocaine as an example of a drug that blocks reuptake of the neurotransmitter.
Describe Hardy–Weinberg equation and calculations of allele or genotype frequencies
The Hardy–Weinberg equation is a mathematical model used to calculate allele and genotype frequencies in a population that is not evolving. The equation is:
p² + 2pq + q² = 1,
where:
p = frequency of the dominant allele
q = frequency of the recessive allele
p² = frequency of homozygous dominant genotype
2pq = frequency of heterozygous genotype
q² = frequency of homozygous recessive genotype
If you know one genotype frequency (e.g., q²), you can calculate q, then p, and use the equation to find other genotype frequencies.