2h Transport

Question 1

why simple, unicellular organisms can rely on diffusion for movement of
substances in and out of the cell

Answer 1

Because they have a large surface area to volume ratio. Therefore there have more efficient rate of diffusion, allowing a cell to rely on diffusion to transport necessary substance in and out of the cell

Question 2

understand the need for a transport system in multicellular organisms

Answer 2

Multicellular organisms have a small surface area to volume ratio, therefore they cannot rely on diffusion to transport substance. As a result, they rely on transport systems to provide a constant supply of necessary substances through a medium to the cells via an exchange system

Question 3

Phloem

Answer 3

Transports food materials (mainly sucrose and amino acids). Made by the plant from photosynthesis using leaves to non-photsynthesis regions in roots and stem

Question 4

Xylem

Answer 4

Transport water and minerals from the roots to the stem and leaves

Question 5

Composition of the blood

Answer 5

Red blood cells, white blood cells, platelets and plasma

Question 6

Plasma

Answer 6

Liquid part of the blood.

Carries: red blood cells, dissolved nutrients, hormones, CO2 and distributes heat

Question 7

Red blood cells

Answer 7

Carry oxygen in haemoglobin around the body

Question 8

Adaptations of red blood cells

Answer 8

Full of haemoglobin
No nucleus
Disc-shaped
High SA : Vol
Diameter of a red blood cell is slightly bigger than the average diameter of a capillary

Question 9

Lymphocytes

Answer 9

Produces antibodies to destroy microrganisms

Question 10

Phagocytes

Answer 10

Digests and destroy bacteria and othe microgranisms that have infected the body

Question 11

Arteries

Answer 11

• Carry blood away from the heart to the organs
• The blood is under high pressure so the walls must be able to stretch and recoil.
• Generally carry oxygenated blood
• Arterioles are small arteries
• They carry blood into organs from the main arteries

Question 12

Veins

Answer 12

• Carry blood from organs back towards the heart
• Under low pressure
• Must allow blood to pass through easily and prevent it flowing backwards
• Mainly carry deoxygenated blood
• They have valves to prevent backflow

Question 13

Capillaries

Answer 13

• Carry blood through organs, bringing the blood close to every cell in the organ
• They are permeable so that the substances are transferred between the blood and the cells
• Their walls are only 1 cell thick

Question 14

Structure of the heart

Answer 14

It is a muscle with four main parts:
The left and right atrium, the left and right ventricle.

Deoxygenated blood is enters in the right atrium through the vena cava.

This blood is propelled to the right ventricle through the atrioventricular valves.

The right ventricile contracts and propelles unoxygenated blood to the lungs through the pulmonary artery.

Oxygenated blood from the lungs enters the left atrium through the pulmonary vein.

This blood is propelled to the left ventricle through the atrioventricular valves.

The left ventricle contracts and proplelles oxygenated blood to the aorta.

Question 15

Parts of the circulatory system

Answer 15

Blood vessels, heart, lungs, liver and kidneys

Question 16

Factors and consequences for developing coronary heart disease

Answer 16

Smoking - Reduced blood flow
High fat diet - oxygen insufficiency
Lack of exercise - Musscle cells can't respond
Stress - Muscle cells die
Genetics - Heart attack

Question 17

Heart rate during exercise

Answer 17

1. Heart rate changes during exercise to provide the heart with more oxygen for aerobic respiration. It increases to increase oxygen supply.
2. Heart rate and blood volume increases
3. Adrenaline increases heart rate