3.2.1: Gas exchange in small organisms

Question 1

how does the gas exchange surface maintain a large surface area for an amoeba

Answer 1

Large SA:Vol, don’t move about a lot and so have low metabolic rates so relatively low oxygen requirements

Question 2

how does the gas exchange surface maintain a large surface area for a flatworm

Answer 2

tubular and flattened shape which increases their SA:Vol. don’t move about a lot and so have low metabolic rates so relatively low oxygen requirements

Question 3

how does the gas exchange surface maintain a large surface area for an earthworm

Answer 3

tubular shape increases their SA:Vol. don’t move about a lot and so have low metabolic rates so relatively low oxygen requirements

Question 4

how does the gas exchange surface maintain a short diffusion pathway for an amoeba

Answer 4

the cell surface membrane is thin

Question 5

how does the gas exchange surface maintain a short diffusion pathway for a flatworm

Answer 5

skin is thin so short distance between the air and the blood capillaries beneath the skin surfaces

Question 6

how does the gas exchange surface maintain a short diffusion pathway for an earthworm

Answer 6

skin is thin so short distance between the air and the blood capillaries beneath the skin surfaces

Question 7

how does the gas exchange surface maintain a steep concentration gradient for an amoeba

Answer 7

converts the oxygen to ATP so the oxygen levels in the cytoplasm remain lower than the external environment

Question 8

how does the gas exchange surface maintain a steep concentration gradient for a flatworm

Answer 8

constant removal of oxygen and taking it to the cells while bringing carbon dioxide back

Question 9

how does the gas exchange surface maintain a steep concentration gradient for an earthworm

Answer 9

constant removal of oxygen and taking it to the cells while bringing carbon dioxide back, have haemoglobin in their closed circulatory system which increases the efficiency of oxygen transport therefore moving oxygen away from the skin’s surface more quickly

Question 10

what are any other factors that increase efficiency of gas exchange for an amoeba

Answer 10

cell surface membrane is moist for gases to dissolve

Question 11

what are any other factors that increase efficiency of gas exchange for a flatworm

Answer 11

skin is moist for gases to dissolve

Question 12

what are any other factors that increase efficiency of gas exchange for an earthworm

Answer 12

skin is moist for gases to dissolve