Cells and processes
What is the function of the cell membrane?
(Answer: Controls what enters and leaves the cell)
What is the function of red blood cells?
(Answer: Carry oxygen using haemoglobin)
What gas do plants take in during photosynthesis?
(Answer: Carbon dioxide)
What is a chromosome made of?
DNA
In the osmosis potato practical, looking at change in mass in potatoes, what is the independent variable?
Concentration of solution
What organelle is responsible for photosynthesis?
(Answer: Chloroplast)
Name the four chambers of the heart.
(Answer: Left atrium, right atrium, left ventricle, right ventricle)
What is a producer in a food chain?
(Answer: An organism that makes its own food, e.g., plants)
What base pairs bond in DNA?
(Answer: A with T, C with G)
What is the indicator used to test for starch in a leaf?
Iodine
Name two differences between plant and animal cells.
(Answer: Plant cells have a cell wall and chloroplasts; animal cells do not)
What is the difference between arteries and veins?
(Answer: Arteries carry blood away from the heart under high pressure; veins carry it back under lower pressure with valves)
Name two causes of deforestation.
(Answer: Logging, agriculture, urbanisation)
Define allele.
(Answer: A version of a gene)
In the enzyme activity practical, what two factors are commonly changed?
(Answer: Temperature and pH)
What is the formula for aerobic respiration?
(Answer: glucose + oxygen → carbon dioxide + water)
What role does the alveoli play in gas exchange?
(Answer: Site of oxygen and carbon dioxide diffusion between lungs and blood)
What is bioaccumulation?
(Answer: The build-up of harmful substances like pesticides in a food chain)
What is the difference between dominant and recessive alleles?
(Answer: Dominant alleles always show if present; recessive alleles only show when two copies are present)
Why do we boil a leaf in ethanol when testing for starch?
(Answer: To remove chlorophyll so results are visible)
Explain the process of osmosis and where it occurs in plant cells.
(Answer: Osmosis is the diffusion of water through a partially permeable membrane from a dilute to a more concentrated solution; occurs in root hair cells, vacuole, etc.)
Describe the body's immune response to a pathogen.
(Answer: Lymphocyte cells produce antibodies and phagocytes engulf pathogens through phagocytosis)
Explain how global warming is caused and its impact on biodiversity.
(Answer: Caused by greenhouse gases like COâ‚‚; leads to habitat loss, changing climates, extinction)
A child has cystic fibrosis, but neither parent has the condition. What must their genotypes be?
(Answer: Both must be carriers – heterozygous)
Describe how you would investigate the effect of light on photosynthesis using pondweed.
(Answer: Use a light source, count bubbles of oxygen or measure oxygen released, change distance to alter light intensity)