Biology
Cells and movement of substances — Topics 1-3
- 1.
A cell image is 48 mm long. The actual cell is 0.12 mm long. Calculate the magnification.
[3 marks] - 2.
Explain why a plant cell becomes turgid when placed in pure water.
[4 marks] · no calculator - 3.
State three structures found in a plant cell but not in an animal cell.
[3 marks] · no calculator - 4.
Define diffusion, and explain why a substance diffuses faster when the concentration gradient is steeper.
[3 marks] · no calculator - 5.
Explain why a red blood cell placed in distilled water eventually bursts (lyses), while a plant cell placed in distilled water does not.
[3 marks] · no calculator - 6.
Explain why active transport, unlike diffusion, requires energy from respiration.
[3 marks] · no calculator - 7.
Root hair cells are adapted for the efficient uptake of water and mineral ions. Describe two features of a root hair cell that adapt it for this function.
[3 marks] · no calculator - 8.
Outline the function of the nucleus, cell membrane and cytoplasm in a generalised animal cell.
[3 marks] · no calculator - 9.
A student is given an unlabelled slide and asked to determine whether the cells shown are plant or animal cells. State two observable features that would allow this distinction.
[2 marks] · no calculator - 10.
Explain why, in a osmosis experiment using visking (dialysis) tubing, glucose can pass through the tubing but starch cannot.
[3 marks] · no calculator - 11.
Explain, using an example, the difference between a tissue, an organ and an organ system.
[3 marks] · no calculator - 12.
Describe three features of a sperm cell that adapt it for its function of fertilising an egg cell.
[3 marks] · no calculator - 13.
Describe three features of a nerve cell (neurone) that adapt it for its function of rapidly transmitting electrical impulses.
[3 marks] · no calculator - 14.
Describe three features of a palisade mesophyll cell that adapt it for efficient photosynthesis.
[3 marks] · no calculator - 15.
Describe three features of a red blood cell that adapt it for its function of transporting oxygen.
[3 marks] · no calculator - 16.
An image of a cell has a magnification of ×250. If the image is 20 mm long, calculate the actual length of the cell, in micrometres (μm).
[3 marks] - 17.
A cell has an actual length of 0.025 mm. Calculate the length of its image, in mm, at a magnification of ×2000.
[2 marks] - 18.
A student places equal-sized cylinders of potato tissue into different concentrations of sugar solution and measures their mass before and after 24 hours. State what would happen to the mass of a potato cylinder placed in (a) pure water, and (b) a concentrated sugar solution, explaining each in terms of osmosis.
[4 marks] · no calculator - 19.
Explain why surface area to volume ratio decreases as an organism (or cell) increases in size, and state why this is important for larger organisms.
[3 marks] · no calculator - 20.
State three factors, other than the concentration gradient, that affect the rate of diffusion.
[3 marks] · no calculator - 21.
Explain how facilitated diffusion allows large or charged molecules, such as glucose, to cross a cell membrane, and state one way it is similar to simple diffusion.
[3 marks] · no calculator - 22.
State what a plant cell wall is made of, and describe two functions it performs.
[3 marks] · no calculator - 23.
State a formal definition of osmosis, in terms of water potential and a partially permeable membrane.
[3 marks] · no calculator - 24.
Describe three features of a xylem vessel that adapt it for the transport of water.
[3 marks] · no calculator - 25.
Describe three features of phloem tissue that adapt it for the transport of dissolved sugars (translocation).
[3 marks] · no calculator