Most Common IGCSE Biology Questions

Question 1

Define the term diffusion

Answer 1

• ->the movement of particles
• ->From an area of higher concentration
• ->to an area of lower concentration

Question 2

Define the term osmosis

Answer 2

• ->Movement of water
• ->from a more dilute solu. to a more conc solu.
• ->thru a part. permeable membrane

Question 3

Define the term active transport

Answer 3

• ->Movement of part.
• ->from an area of lower conc. to an area of higher conc.
• ->Using energy from respiration

Question 4

State the ways in which the structure of an artery differs from the structure of a vein.

Answer 4

Arteries have…

• ->thicker walls
• ->More elastic tissue
• ->a smaller lumen
• ->no valves, but veins have valves

Question 5

Explain how human lung tissue allow efficient gas exchange

Answer 5

• ->alveoli prov. large SA
• ->alveoli walls one cell thick
  
  • ->short diffu. path.
• ->alveoli walls moist
  
  • ->for gases 2 dissolve
• ->capillary wall one cell thick
  - ->short diffu. path.
• ->The flowing blood maint. conc. grad.

Question 6

Explain how the structure of the small intestine in adapted for efficient exchange of substances

Answer 6

• ->villi prov. large SA
• ->villi have thin walls for short diffu. path.
• -> villi have MANY capp. to ab. glucose
• ->blood supply maintains a diffu. gradient
• ->villi have LACTEALS to ab. fatty acids and glycerols
• -> lacteals long to give LARGE SA

Question 7

Design an investigation…

Answer 7

C- change
O-organism
R-reliable
M-measurement
M-measurement
S-same
S-same