Recall — GCSE Flashcards
🧬 GCSE Biology Flashcards
Cells, organisms, ecosystems and genetics — 10 free revision cards. Study them below, or add the whole deck to Recall and let FSRS spaced repetition schedule your revision so it actually sticks.
Name four organelles found in plant cells but not animal cells.
1. Cell wall (cellulose)
2. Chloroplasts (photosynthesis)
3. Permanent vacuole (turgor)
4. Plasmodesmata (channels between cells)
2. Chloroplasts (photosynthesis)
3. Permanent vacuole (turgor)
4. Plasmodesmata (channels between cells)
Write the word equation for photosynthesis.
$$\text{carbon dioxide} + \text{water} \xrightarrow{\text{light}} \text{glucose} + \text{oxygen}$$
Balanced: $6\text{CO}_2 + 6\text{H}_2\text{O} \to \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2$
Balanced: $6\text{CO}_2 + 6\text{H}_2\text{O} \to \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2$
What is the role of the mitochondria?
Site of aerobic respiration — releases energy from glucose.
$\text{glucose} + \text{oxygen} \to \text{CO}_2 + \text{water} \,(+ \text{ATP})$
$\text{glucose} + \text{oxygen} \to \text{CO}_2 + \text{water} \,(+ \text{ATP})$
State the levels of organisation in a multicellular organism.
Cell → Tissue → Organ → Organ system → Organism
Example: Muscle cell → muscle tissue → heart → circulatory system → human.
Example: Muscle cell → muscle tissue → heart → circulatory system → human.
What is the role of enzymes?
Biological catalysts — speed up reactions without being used up.
Work on the lock-and-key model: each enzyme has a specific active site shape. Denatured by high temp / extreme pH.
Work on the lock-and-key model: each enzyme has a specific active site shape. Denatured by high temp / extreme pH.
Compare arteries, veins and capillaries.
Arteries: thick muscular walls, carry blood away from heart at high pressure.
Veins: thinner walls + valves, carry blood back to heart.
Capillaries: one cell thick, where exchange of $\text{O}_2$, $\text{CO}_2$ and nutrients happens.
Veins: thinner walls + valves, carry blood back to heart.
Capillaries: one cell thick, where exchange of $\text{O}_2$, $\text{CO}_2$ and nutrients happens.
What is natural selection (Darwin)?
1. Individuals show variation
2. Those best adapted survive to reproduce
3. They pass advantageous traits to offspring
4. Over generations, the population evolves
"Survival of the fittest" — fittest = best suited to environment.
2. Those best adapted survive to reproduce
3. They pass advantageous traits to offspring
4. Over generations, the population evolves
"Survival of the fittest" — fittest = best suited to environment.
Define homeostasis and give three things it regulates.
Maintaining a constant internal environment despite external changes.
Regulates: body temperature, blood glucose, water balance (and CO₂, pH).
Regulates: body temperature, blood glucose, water balance (and CO₂, pH).
What are the products of anaerobic respiration in humans vs yeast?
Humans: glucose → lactic acid (causes muscle fatigue, oxygen debt)
Yeast: glucose → ethanol + CO₂ (fermentation, used in brewing/bread)
Yeast: glucose → ethanol + CO₂ (fermentation, used in brewing/bread)
What is DNA and where is it found?
Deoxyribonucleic acid — a double helix polymer made of nucleotides.
Found in the nucleus of cells, organised into chromosomes. Humans have 23 pairs (46 total).
Bases: A-T, C-G.
Found in the nucleus of cells, organised into chromosomes. Humans have 23 pairs (46 total).
Bases: A-T, C-G.
These 10 cards are a free starter deck — a companion for memorising the core facts, not a complete course. In the Recall app you can also paste your own class notes and have AI build decks for the topics your exam board covers.