transport in animals

Question 1

How is our circulatory system a mass transport system?

Answer 1

A mass transport system is a way that larger organisms move. These substances are carried together in a liquid e.g. blood and are moved by a mechanism e.g. the heart

Question 2

what is our circulatory system comprised of?

Answer 2

A liquid medium that circulates

Vessels to carry the transport medium

A pumping mechanism

Question 3

suggest 3 ways in which the use of embryonic stem cells in research has practical benefits to biological knowledge.

Answer 3

• can be grown into different tissus to test how effective new medicinal drugs are (1)
• can be grown into different tissues to test for toxicity of new drugs (1)
• cell function can be studied to find out what can make it fail to work in certain diseases. (1)

Question 4

describe what happens to the blood plasma as it moves from the arterial to venous end in capillary. (3)

Answer 4

plasma / fluid, moves out of, capillary / blood ;
enters / forms, tissue fluid ;
(plasma) proteins, remain in capillary / too large to
pass through capillary wall / AW ;

(fluid moves) down pressure gradient ;
hydrostatic pressure greater than, water potential / Ψ;

Question 5

state how hydrostatic pressure is generated in the heart

Answer 5

contraction of ventricles

Question 6

state what is meant by the term health

Answer 6

mental and physical well-being
absence of disease ;

Question 7

Describe the Bohr (effect / shift) (3)

Answer 7

2 reduces affinity (of Hb) for oxygen ;
3 formation of haemoglobinic acid / hydrogen ions interact
with haemoglobin ;

4 prevents, fall in pH / build-up of H

+, in cells
OR provides buffering effect ;

5 alter, structure / shape, of haemoglobin ;
6 more oxygen released where, needed / more

respiration / carbon dioxide concentration high ;

7 CO2 binds to haemoglobin forming

carbaminohaemoglobin ;

Question 8

Describe how the components of tobacco smoke can affect the cardiovascular system of smokers (7)

Answer 8

• nicotine in tobacco increases stickiness of platelets
• formation of blood clots release adrenaline
• causes constriction of arterioles
• so there is reduced blood flow
• carbon monoxide combines permanently with hemoglobin
• so reduced oxygen carrying capacity of blood
• leading to increased heart rate/ blood pressure