Multicellular organisms require specialised transport systems and exchange surfaces to move substances efficiently throughout their bodies.
The words in the list below represent various organs, vessels, tissues, and processes in animals and plants.
Answer parts (i), (ii), and (iii) using words from this list.
(i) Name the blood vessels that branch off the aorta to supply oxygenated blood directly to the heart muscle.
(ii) Name the plant tissue responsible for transporting dissolved sugars (such as sucrose) from the leaves to the rest of the plant.
(iii) Name the major vein that returns deoxygenated blood from the body back to the right atrium of the heart.
Substances move into and out of cells across exchange surfaces via different transport mechanisms.
Decide which method of transport is used for each process. Copy the table or select the correct cell for each row:
| Process / Substance movement | Active transport | Diffusion | Osmosis |
|---|---|---|---|
| Oxygen gas moving from the air in the alveoli into the surrounding capillary blood | |||
| Nitrate ions being absorbed from a lower concentration in the soil into root hair cells | |||
| Water being reabsorbed from the filtrate in the kidney tubules back into the blood |
17 exam-style questions on OCR GCSE Biology 2.2 The challenges of size, covering 2.2.1 Exchange surfaces and surface area : volume ratio, 2.2.2 Substances transported in organisms, 2.2.3 The human circulatory system, 2.2.4 The heart and blood vessels, 2.2.5 Red blood cells and plasma, 2.2.6 Uptake of water and mineral ions by plants, 2.2.7 Transpiration and translocation, 2.2.8 Xylem and phloem, 2.2.9 Environmental factors and water uptake, and 2.2.10 Using a potometer. Each one has a worked solution and a mark scheme showing where the marks go.