Transport

Question 1

What 2 factors affect the transport of substances in living organisms

Answer 1

The surface area to volume ratio
Limitations of simple diffusion

Question 2

Explain the need for transport systems in multicellular organisms

Answer 2

Unicellular organisms are very small and have a large surface area-to-volume ratio. Diffusion through their body is adequate to take in their requirement.

Multicellular organisms have a small surface area-to-volume ratio. Diffusion through their body isn’t adequate to supply all their body cells with their requirements and remove their waste.

Question 3

Identify the materials which need to be transported in animals and plants

Answer 3

Oxygen
CO2
hormones
Mineral nutrients
Glucose
Amino acids

Question 4

Another name for red and white blood cells and platelets

Answer 4

Red blood cells- erythrocytes
White blood cells- leukocytes
Platelets- thrombocytes

Question 5

Structure of the red blood cell

Answer 5

Biconcave discs with a thin centre
No nucleus
Contain haemoglobin
Slightly elastic

Question 6

How is artificial immunity acquired?

Answer 6

By vaccination

Question 7

Function of the tendon in the heart

Answer 7

Prevent the valve turning inside out

Question 8

Explain how the structure of xylem vessels is suited for their function

Answer 8

Hollow tubes- non-living with lignified walls
No end walls- allow for a continuous flow of water

Tough lignin- to support the plant

Question 9

Discuss the role of transportation in plants

Answer 9

It draws water up to leave for use in photosynthesis

It supplies plant cells with water to keep them turgid

Evaporation of water from the surface cools the plant

Question 10

Describe the effects of external factors on transpiration

Answer 10

Light intensity- in bright light, the stomatas are fully open so water vapour can diffuse out and transpiration is rapid
Temperature- high Temps cause water to evaporate quickly
Humidity- in low humidity, water vapour diffuses easily and transportation is rapid
Wind speed- in windy conditions, transpiration is rapid

Question 11

Discuss adaptation in plants to conserve water

Answer 11

Waxy cuticle to prevent water loss
Leaves of many succulent plants store water
Plants have long rand deep tap-roots to absorb water from deep in the soil

Question 12

Importance of food storage in living organisms

Answer 12

Overcomes the need for continuous food intake and continuous food manufacture in autotrophs

Provides food reserves for periods of scarcity

Provide fit special functions, such as the production of sexual or vegetative reproductive structures and the development of embryos