Biology Flashcards
7 cards from real GCSE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Biology flashcards as text
What evidence from the fossil record supports the theory of evolution by natural selection?
Answer: Fossils reveal a gradual change in organisms over time, showing transitional forms
The fossil record shows gradual anatomical changes across geological time, including transitional fossils that link ancestral and descendant species.
Which term describes a protein that speeds up a chemical reaction without being consumed in the process?
Answer: Enzyme
Enzymes are biological catalysts made of protein that lower activation energy and are regenerated after each reaction.
How does the structure of a red blood cell relate to its function?
Answer: Its biconcave disc shape increases surface area for oxygen diffusion
The biconcave disc shape of red blood cells maximises surface area-to-volume ratio, allowing rapid diffusion of oxygen to and from haemoglobin.
What is meant by the term 'limiting factor' in the context of photosynthesis?
Answer: A factor that is present in the lowest quantity relative to need, restricting the rate of photosynthesis
A limiting factor is the variable present in the least adequate amount that constrains the overall rate of photosynthesis, such as light intensity, CO₂ concentration, or temperature.
Which method of reproduction produces offspring that are genetically identical to the parent?
Answer: Asexual reproduction
Asexual reproduction involves only one parent and no fusion of gametes, producing genetically identical offspring called clones.
What is the role of platelets in the blood?
Answer: Clotting the blood to prevent excessive blood loss
Platelets are cell fragments that accumulate at wound sites, releasing chemicals that initiate the clotting cascade to form a fibrin mesh.
Which adaptation helps a cactus survive in a hot desert environment?
Answer: Thick waxy skin and stomata that open only at night
Cacti have a thick waxy cuticle to reduce water loss, and their stomata open at night (CAM photosynthesis) to minimise transpiration in daytime heat.