transport in animals

Question 1

what is a double circulatory system?

Answer 1

the blood flows through the heart twice for one circuit of the body

Question 2

what is a single circulatory system?

Answer 2

the blood flows through the heart once for one circuit of the body

Question 3

what is transport?

Answer 3

the movement of substances

e.g. oxygen, nutrients, hormones, waste and heat

Question 4

what are the three main factors that effect the need for a transport system?

Answer 4

• size
• surface area to volume ratio
• level of metabolic activity

Question 5

what are the features of a good transport system?

Answer 5

• a fluid to carry nutrients, oxygen and wastes(this is the blood)
• a pump to push all of the above around the body(the heart)
• exchange surfaces (the capillaries)

Question 6

what organisms have a single circulatory system?

Answer 6

-fish

heart –> gills –> body –> heart

Question 7

what organisms have a double circulatory system?

Answer 7

-mammals

heart–> body–> heart–> lungs–> heart

Question 8

what are arteries?

Answer 8

vessels that carry blood away from the heart

Question 9

what are arterioles?

Answer 9

small blood vessels that distribute blood from the arteries to the capillaries

Question 10

what are capillaries?

Answer 10

small vessels with very thin walls

Question 11

what is a closed circulatory system?

Answer 11

blood is held in the vessels

Question 12

what is an open circulatory system?

Answer 12

blood is not in vessels

Question 13

what is a vein?

Answer 13

vessels that carry blood towards the heart

Question 14

what are venules?

Answer 14

small vessels that collect blood from the capillaries and lead into the veins

Question 15

what are the disadvantages of an open circulatory system?

Answer 15

• blood pressure is low and flow is slow

- circulation of blood may be effected by body movements

Question 16

what are the advantages of a closed circulatory system?

Answer 16

• higher pressure, so blood flows quicker
• more rapid delivery of o2 and nutrients
• more rapid removal of waste
• transport is independent of body movements

Question 17

what is the structure of the artery?

Answer 17

• lumen is small
• thick layer of smooth muscle
• relatively thick layer of collagen and elastic tissue

Question 18

what is the structure of a capillary?

Answer 18

• lumen very narrow
• the wall is one cell thick (endothelium)
• walls are leaky

Question 19

what is the structure of a capillary?

Answer 19

• lumen is relatively large
• thinner layers of collagen, elastic tissue and smooth muscle in comparison to arteries
• contain valves

Question 20

what is hydrostatic pressure?

Answer 20

the pressure that fluid exerts when pushing against the sides of a vessel

Question 21

what is lymph?

Answer 21

the fluid held in the lymphatic system which is a system of tubes that returns excess tissue fluid to the blood system.

Question 22

what is oncotic pressure?

Answer 22

the pressure created by osmotic effects of the solutes.

Question 23

draw the movement of tissue fluid.

Answer 23

See page 191 in OCR AS/A-level biology textbook

Question 24

what are atrioventricular valves?

Answer 24

valves between the atria and the ventricles

Question 25

what is cardiac muscle?

Answer 25

specialised muscle found in the walls of hear chambers

Question 26

what are semi-lunar valves?

Answer 26

valves that prevent blood from re entering the heart from the arteries

Question 27

what are coronary arteries?

Answer 27

supply oxygenated blood to the heart

Question 28

what are the 4 chambers of the heart?

Answer 28

left and right ventricle/atria

Question 29

what are the 3 stages of the cardiac cycle?

Answer 29

- ventricular systole - diastole - atrial systole

Question 30

what is bradycardia?

Answer 30

slow heart rhythm

Question 31

what is an ectopic heartbeat?

Answer 31

an extra beat or an early beat of the ventricles

Question 32

what is an electrocardiogram?

Answer 32

a trace that records the electrical activity of the heart.

Question 33

what is myogenic muscle?

Answer 33

muscle that can initiate its own contraction

Question 34

what is affinity?

Answer 34

a strong attraction

Question 35

what is dissociation?

Answer 35

releasing oxygen from oxyhaemoglobin

Question 36

draw a graph to show the partial pressure of o2 and the percentage saturation with oxygen for both fetal and adult haemoglobin.

Answer 36

see page 199

Question 37

what is carbonic anhydrase?

Answer 37

the enzyme that catalyses the combination of co2 and water

Question 38

what is the chloride shift?

Answer 38

the movement of chloride ions into erythrocytes to balance the charge as hydrogen carbonate ions leave the cell

Question 39

what is the Bohr effect?

Answer 39

the effect that CO2 has on haemoglobin, explaining the release of more O2

Question 40

what is haemoglobinic acid?

Answer 40

the compound formed by the buffering action of haemoglobin as it combines with excess hydrogen ions.