BRAINCAKEScaling up
Revision notes for Scaling up in OCR Combined Science A (J250). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Transport into and out of cellsEvery cell must take in useful substances such as oxygen and glucose, and get rid of waste such as carbon dioxide and urea.
- Mitosis and the cell cycleOrganisms grow by making more cells.
- Why cells differentiateA fertilised egg divides by mitosis to make many cells that are all the same at first.
- Where stem cells are foundStem cells are undifferentiated cells.
- Functions of stem cellsStem cells divide by mitosis to make new cells, and some of the new cells can then differentiate into specialised cell types.
- Embryonic and adult stem cellsEmbryonic stem cells come from very early embryos.
- Exchange surfaces and transport systems: surface area to volume ratioA single-celled organism is so small that it has a large surface area compared with its volume.
- Substances transported into and out of organismsEvery cell needs a supply of the substances it uses and a way to remove the substances it makes.
- The human circulatory systemThe human circulatory system is a double circulatory system.
- Adaptations of the heart and blood vesselsThe heart is a muscular pump made mostly of cardiac muscle, which contracts without tiring.
- Red blood cells and plasmaRed blood cells carry oxygen from the lungs to every cell of the body.
- Uptake of water and mineral ions by plantsPlants take in water and mineral ions from the soil through root hair cells.
- Transpiration, translocation and stomataTranspiration is the loss of water vapour from the leaves of a plant.
- Xylem and phloem structureXylem vessels carry water and mineral ions from the roots up to the leaves, in one direction only.
- Environmental factors and water uptakeWater is pulled up through the xylem as water is lost from the leaves by transpiration.
- Using a potometerA potometer measures the rate of water uptake by a plant cutting.