Topic 8 - Transport Sytsems

Question 1

What does the red blood cell do and how is it adapted?

Answer 1

Red blood cells (erythrocytes):
• Transport oxygen from lungs to all cells in body - haemoglobin binds to oxygen to form oxyhemoglobin
• Biconcave disk - large surface area to volume ratio for more oxygen to diffuse in per second
• No nucleus - contains more haemoglobin to carry more oxygen.

Question 2

What are the 2 types of white blood cells?

Answer 2

Phagocytes
Lymphocytes

Question 3

What do the phagocytes do and how are they adapted?

Answer 3

• Large flexible membranes
• Engulf (surround) and digest pathogens

Question 4

What do the lymphocytes do and how are they adapted?

Answer 4

• Produce antibodies and antibodies which stick to pathogens and help destroy them.

Question 5

What do platelets do and how are they adapted?

Answer 5

• Fragments of cells with no nucleus
• Make chemicals that help blood clot at a wound

Question 6

What does plasma do and how is it adapted?

Answer 6

• Straw coloured liquid part of the blood
• Carries RBCs, WBCs, platelets, dissolved glucose, carbon dioxide and hormones.

Question 7

How is the alveoli adapted to gas exchange?

Answer 7

• Large surface area for quicker gas exchange maintaining steep concentration gradient.
• Very thin for a shorter diffusion pathway
• Good blood supply to maintain a steep concentration gradient

Question 8

How does carbon dioxide move in the alveoli?

Answer 8

• Carbon dioxide moves from the blood to the alveoli
• Carbon dioxide moves from an area of high concentration to a low concentration
• Carbon dioxide moves down a concentration gradient

Question 9

How does oxygen move in the alveoli?

Answer 9

• Oxygen moves from the alveoli to the blood
• Oxygen moves from a high concentration to a low concentration
• Oxygen moves down the concentration gradient

Question 10

What are the 3 blood vessels?

Answer 10

Veins
Capillaries
Arteries

Question 11

What do the veins do?

Answer 11

Carry blood to the heart.

Question 12

What are features of the veins?

Answer 12

• Carry blood under lows pressure so walls don’t need to be as thick as artery walls
• Don’t need to be as strong
• Bigger lumen than artery to help blood flow
• Valves to stop blood flowing backwards

Question 13

What do the capillaries do?

Answer 13

Carry blood close to cells for exchange of materials.

Question 14

What are features of the capillaries?

Answer 14

• Arteries branch into the capillaries
• Really small
• Narrow so can squeeze into gaps between cells to exchange substances
• Permeable walls for substances to diffuse in and out
• One cell thick to increase rate of diffusion by decreasing distance over which it occurs
• Supply nutrients and oxygen, take away CO2

Question 15

What do the arteries do?

Answer 15

Carry blood away form the heart.

Question 16

What are features of arteries?

Answer 16

• Carry blood under high pressure so walls are strong and elastic.
• Thick muscular walls
• Small lumen
• Elastic fibres to allow them to stretch and spring back

Question 17

What is aerobic respiration?

Answer 17

Respiration that involves oxygen.

Question 18

What is the word equation for aerobic respiration?

Answer 18

Glucose + oxygen —> Carbon dioxide + water

Question 19

What are features of aerobic respiration?

Answer 19

• Most efficient
• Uses oxygen
• Occurs in mitochondria
• Produces water
• Releases more energy

Question 20

What is anaerobic respiration?

Answer 20

Respiration that doesn’t involve oxygen.

Question 21

What is the equation for anaerobic respiration in animals and plants?

Answer 21

Animals:
Glucose —> lactic acid
Plants:
Glucose —> ethanol + carbon dioxide

Question 22

What are features of anaerobic respiration?

Answer 22

• Produces lactic acid
• Doesn’t use oxygen
• Short periods of time
• Occurs in cytoplasm
• Releases less energy
• Glucose breakdown is incomplete

Question 23

How does oxygen get into and travel around the body?

Answer 23

Breathing in air
Binds to haemoglobin in red blood cells and travels in the blood.

Question 24

How does glucose get into and travel around the body?

Answer 24

Digestion
Travels in plasma in blood

Question 25

How does carbon dioxide get into and travel around the body?

Answer 25

Dissolves into plasma Diffuses into alveoli and breathed out

Question 26

How to workout surface area to volume ratio?

Answer 26

Calculate the surface area by: Area of 1 side X number of sides Caducate volume by: L X W X H

Question 27

Why do multicellular organisms have specialised exchange and mass transport systems?

Answer 27

Small surface area to volume ratio. Difficult to exchange enough substances to supply their volume.

Question 28

Why do single celled organisms not have specialised exchange and transport systems?

Answer 28

Gasses and dissolved substances diffuse directly into (or out of) cell across cell membrane because they have a large surface area to volume ratio.

Question 29

What is the definition of respiration?

Answer 29

Respiration is a chemical reaction in which energy is transferred from glucose. This is done through the oxidation of glucose. Oxidation means to react with oxygen.

Question 30

What happens on the left side of the heart?

Answer 30

Oxygenated blood enters from the pulmonary vein (from lungs) through the aorta (artery) to the rest of the body.

Question 31

What happens on the right side of the heart?

Answer 31

Deoxygenated blood enters from the venacava (vein) to the pulmonary artery (to lung).

Question 32

What is the definition of heart rate?

Answer 32

The number of times the heart beats per minute. B/m

Question 33

What is the definition of stroke volume?

Answer 33

The volume of blood pushed into the aorta each beat, measured in litres. L/b

Question 34

What is the definition of cardiac output?

Answer 34

The volume of blood pushed into the aorta each minute. L/m

Question 35

Equation for cardiac output?

Answer 35

Cardiac output = stroke volume X heart rate

Question 36

Why does the left side of the heart have thicker muscular walls?

Answer 36

It pumps blood further around the body under higher pressure.

Question 37

What are the different types of exchange of substances?

Answer 37

• Cells take in oxygen for aerobic respiration which produces carbon dioxide as a waste products. This happens by diffusion. • Water is taken up by cells by osmosis. In animals dissolved food molecules and mineral ions diffuse along with it. • Urea diffuse from cells to the blood plasma for for removal from the body by the kidneys.