Unit 1 KA 1-3 & 5 & Unit 2 Key Areas 1-4 Latest
Update 2025-2026 80 Questions and 100%
Verified Correct Answers Guaranteed A+
Cyclin-Dependent Kinases (CDKs) Kinase enzymes that, when active, phosphorylate
Rb and prevent it from binding to the DNA. - CORRECT ANSWER:
Describe the structure of the microtubules. - CORRECT ANSWER: Hollow tubes made
up of the protein tubulin
How do you recognise a basic R group? - CORRECT ANSWER: It has a positive
charge.
How do you recognise an acidic R group? - CORRECT ANSWER: It has a negative
charge.
In what environments are K selected species more common? - CORRECT ANSWER:
Stable populations at or near their carrying capacity
Under what conditions is parthenogenesis more common? - CORRECT ANSWER: In
cooler climates with low parasite density or diversity.
What are chiasmata? - CORRECT ANSWER: Points of contact between non-sister
chromatids of homologous chromosomes. Sections of DNA are exchanged between
these chromatids at this point.
What are homologous chromosomes? - CORRECT ANSWER: Chromosomes that pair
up during meiosis. They are the same size, have the same centromere position, and the
same sequence of genes at the same loci.
, What are linked genes? - CORRECT ANSWER: Genes located on the same
chromosome. Crossing over can result in new combinations of the alleles of these
genes.
What are the conditions for maintaining the HW equilibrium - CORRECT ANSWER: No
natural selection, random mating, no mutation, large population size and no gene flow
(migration)
What are the functions of caspases? - CORRECT ANSWER: A family of enzymes that
break down proteins during the process of apoptosis.
What are the spindle fibres made of? - CORRECT ANSWER: microtubules
What does heterogametic mean? - CORRECT ANSWER: When an organism has two
different types of sex chromosome in their genotype (e.g.XY)
What is a carrier female? - CORRECT ANSWER: A female who carries the gene for a
particular recessive genetic condition, but is not affected by it. She will be heterozygous
for the condition.
What is a cyclin? - CORRECT ANSWER: Proteins that accumulate during the G1 phase
and bind with CDKs to form active cyclin-CDK complexes.
What is a degenerative disease? - CORRECT ANSWER: A disease caused by an
uncontrolled decrease in the rate of the cell cycle.
What is a disulphide bridge? - CORRECT ANSWER: A covalent bond between the
sulphurs of two R groups involved in maintaining the tertiary and quaternary structure.