RP5 - mass transports within systems (plants and humans)

Question 1

describe how the student returned the air bubble to the start of the capillary tube

Answer 1

use tap/open/add water from reservoir

Question 2

give two precautions students should have taken when setting up the potometer to obtain reliable measurements of water uptake by the plant shoot

Answer 2

any two from
- cut shoot at slant
- cut shoot underwater
- seal joints
- ensure no air bubbles present
- note where bubble starts

Question 3

a potometer measures rate of water uptake rather than transpiration. give 2 reasons why it does not truly measure rate of transpiration.

Answer 3

any 2 from:
- water used in photosynthesis
- water produced in respiration
- water used for support
- apparatus not sealed

Question 4

explain the relationship between number of leaves removed from plant and rate of transpiration

Answer 4

• as more leaves removed, rate of transpiration decreases
• less stomata/surface area
• less evaporation
• less cohesion

Question 4

explain the relationship between number of leaves removed from plant and rate of transpiration

Answer 4

• as more leaves removed, rate of transpiration decreases
• less stomata/surface area
• less evaporation
• less cohesion

Question 5

give 2 ways a scientific drawing can be improved

Answer 5

any 2 from
- no shading
- straight lines
- add annotations
- don’t cross annotations
- add magnification scale

Question 6

explain how presence of gills adapts damselfly to its way of life

Answer 6

• damselfly = high respiratory rate
• uses more oxygen per unit of time

Question 7

give 2 safety precautions when dissecting heart

Answer 7

• cut away from body
• use a sharp scalpel
• disinfect desk after use