Chapter 9 Transport In Plants

Question 1

Describe circulatory system

Answer 1

a system of blood vessels with a pump and valves to ensure one-way flow of blood

Question 2

Describe the single circulation of a fish

Answer 2

There heart has two chamber so the blood flows into the heart once in one circulation.
Blood is oxygenated by gills and blood pressure to other organs is low

Question 3

Describe the double circulation of a mammal

Answer 3

the blood passes through the heart twice before completing a full circuit of the body

Question 4

Explain the advantages of a double circulation

Answer 4

pressure, speed of flow and no mixing of oxygenated and deoxygenated blood

Question 5

Heart parts

Answer 5

muscular wall, septum, left and right ventricles, left and right atria, one-way valves, coronary arteries, atrioventricular and semilunar valves

https://cdn.savemyexams.com/cdn-cgi/image/f=auto,width=1920/uploads/2022/05/human-heart-structure.png

Question 6

Which ventricle muscle wall is thicker

Answer 6

WALL OF LEFT VENTRICLE
IS MUCH THICKER THAN
THE WALL OF THE RIGHT
VENTRICLE

Question 7

muscle walls of the atria compared to the ventricles

Answer 7

The walls of the ventricles are more muscular than those of the atria

Question 8

importance of the septum

Answer 8

separating oxygenated and deoxygenated blood

Question 9

Describe the functioning of the heart

Answer 9

After your atria pump blood into the ventricles, the valves between the atria and ventricles close to prevent backflow.

After your ventricles contract to pump blood away from the heart, the aortic and pulmonary valves close

Question 10

Blood vessels that pump away and into the heart

Answer 10

blood is pumped away from the heart in arteries and returns to the heart in veins

Question 11

activity of the heart may be monitored by

Answer 11

ECG, pulse rate and listening to sounds of valves closing

Question 12

Explain the effect of physical activity on the heart rate

Answer 12

As the muscles are working more, they require more energy, and hence, need more oxygen. This means that more blood needs to be pumped to the muscular tissue, so the heart works faster, hence increasing the pulse rate.

Question 13

Describe coronary heart disease

Answer 13

the blockage of coronary arteries
by a build-up of fatty plaques. They can prevent or restrict blood flow

Question 14

state the possible risk factors of coronary heart disease

Answer 14

diet- saturated fat increases cholesterol level ( increase build up of plaques)
lack of exercise
stress- hormones increase blood pressure increase blockage chance
smoking- nicotine narrows blood vessels increasing blood pressure which cause the build up of fat globules. If in coronary then coronary heart disease
genetic predisposition- if in family most likely to develop
age- older increases possibility
sex- male that females

Question 15

Discuss the roles of diet and exercise in reducing the risk of coronary heart disease

Answer 15

exercise can reduce the risk of cardiovascular disease, as it increases the blood supply to the heart and reduces cholesterol levels.

Diet-Reduce animal fats in diet and eat more fruits and vegetables

Question 16

Structure of arteries

Answer 16

Thick wall - high blood pressure
Narrow lumen
No valves

Question 17

Structure of veins

Answer 17

Less thick - blood pressure low
Wide lumen
Have valves - to prevent back flow

Question 18

Structure of capillaries

Answer 18

Walls one cell thick
Small lumen

Question 19

Explain how the structure of capillaries is related to their functions

Answer 19

Capillaries have very thin walls that are only 1 cell thick. These walls are also very permeable (leaky!!). This allows the carbon dioxide, oxygen and nutrients to diffuse between cells and vessels. They carry blood at a very low pressure so don’t need any muscular walls.

Question 20

main blood vessels to and from

Answer 20

Lungs: pulmonary artery( deoxygenated) and pulmonary vein (oxygenated)
Kidney: renal artery (bottom) and renal vein (on top)

Question 21

main blood vessels to and from

Answer 21

lungs: pulmonary artery ( deoxygenated) and pulmonary vein (oxygenated)
kidney: renal artery (bottom) and renal vein (top)
Liver: hepatic artery, hepatic veins and hepatic portal vein

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Question 22

components of blood

Answer 22

red blood cells, white blood cells, platelets and plasma

Question 23

components of blood

Answer 23

red blood cells, white blood cells, platelets and plasma

Question 24

Functions of blood components

Answer 24

-red blood cells in transporting oxygen, including the role of haemoglobin
-white blood cells in phagocytosis and antibody production
-platelets in clotting
- plasma in the transport of blood cells, ions,
- nutrients, urea, hormones and carbon dioxide

Question 25

functions of lymphocytes

Answer 25

antibody production

Question 26

Function of phagocytes

Answer 26

engulfing pathogens by phagocytosis

Question 27

Role of blood clothing

Answer 27

preventing blood loss and the entry of pathogens

Question 28

Describe the process of clotting

Answer 28

damage to the endothelium releases clotting factors
clotting factors convert the enzyme prothrombin to thrombin
thrombin causes the plasma protein fibrinogen to form threads of fibrin
fibrin threads mesh together clotting the blood and sealing the wound
scar tissue forms on this scaffold creating a clot

conversion of fibrinogen to fibrin to form a mesh