Paper 2 Easy Rev before exam Flashcards
(21 cards)
What are the two main stages of photosynthesis?
Light-dependent and light-independent reactions
Where does the light-dependent reaction occur?
Thylakoid membranes in the chloroplast
What does the light-dependent reaction produce?
ATP, NADPH, and oxygen (as a byproduct)
What molecule is regenerated in the Calvin cycle?
RuBP (ribulose bisphosphate)
What is chemiosmosis?
The movement of H⁺ ions across a membrane to generate ATP via ATP synthase
What is a reflex arc?
A rapid, involuntary response involving sensory, relay, and motor neurons
What detects pressure changes in skin?
Pacinian corpuscles
What is the role of the SAN in the heart?
Acts as the pacemaker, initiating the heartbeat
What is the function of a synapse?
Allows communication between neurons using neurotransmitters
What does myelin do?
Increases the speed of nerve impulse conduction
What is a gene?
A sequence of DNA that codes for a polypeptide
What is meant by codominance?
Both alleles are expressed in the phenotype
What is the Hardy-Weinberg equation used for?
Calculating allele, genotype, and phenotype frequencies in a population
What causes genetic variation?
Mutation, meiosis (crossing over & independent assortment), and random fertilisation
What is stabilising selection?
Selection that favours the average phenotype and reduces variation
What is a mutation?
A change in the DNA base sequence
What is epigenetics?
The study of heritable changes in gene function without changes to DNA sequence
What do transcription factors do?
Regulate gene expression by binding to DNA
How do siRNAs work?
They bind to mRNA and cause it to be broken down, preventing translation
What is cancer caused by?
Uncontrolled cell division due to mutations in proto-oncogenes or tumour suppressor genes
