Biology || Exchange Of Materials B8

Question 1

Single Cell Organisms Transferring Substances?

Answer 1

Can diffuse substances and gases directly into or out cell because they have a large surface area compared to their volume.

Question 2

Multicellular Organisms Transferring Substances?

Answer 2

Smaller surface area compared to volume,

Difficult to exchange substances to supply to the whole volume,

They have a mass transport system that allows them to transfer substances.

Question 3

What Do Lungs Do?

Answer 3

Remove carbon dioxide from the blood and provide the blood with oxygen.

Question 4

Alveoli?

Answer 4

Where gas exchange takes place,

Blood arriving to alveoli has been around the whole body so it contains lots of CO2 and not much O2,

This increase the concentration gradient for diffusion of both gasses,

02 diffused our air into the alveoli,

CO2 diffuses out the alveoli and is breathed out.

Question 5

Adaptations Of Alveoli?

Answer 5

Moist so they can dissolve gasses,

Good blood supply available to them,

Thin walls (one cell thick) so diffusion is easy,

Large surface area.

Question 6

Arteries?

Answer 6

Carries blood away from the heart,

Heart pumps blood at high pressure so the artery walls and strong and elastic,

Walls are thicker and have more uncles to keep them strong,

Lumen is smaller compared to the size of muscle layers,

Don’t have a nucleus.

Question 7

Capillaries?

Answer 7

Exchange of materials at tissue,

Thin walls (only one cell thick),

Arteries branch into capillaries,

TINY!,

They are narrow so they can squeeze into gaps between cells which allows them to easily exchange materials between cells,

They have permeable walls so substances can diffuse in and out,

Supply food and oxygen and take away waste (CO2),

Have a nucleus.

Question 8

Vines?

Answer 8

Carry blood to the heart,

Capillaries join to form vines,

Low pressure so walls are not as thick as arteries,

Lumen is bigger to help blood flow because the pressure of blood is low,

They have valves to help blood flow in the right direction.

Question 9

Red Blood Cells?

Answer 9

Red blood cells (erythrocytes) carry oxygen,

Biconcave (disc shape),

Don’t have a nucleus which allows to carry more oxygen,

Contain haemophilia which contains iron and gives the blood cell the red pigment,

In lungs, haemoglobin binds with oxygen to make oxyhemoglobin. The reverse of this happens in the blood tissue.

Question 10

White Blood Cells?

Answer 10

Have a nucleus,

Phagocytes shape to engulf unwelcome microorganisms (this is called phagocytosis),

Lymphocytes produce antibodies against micro-organisms,

Produce antitoxins to neutralise any toxins produced by microorganisms,

White blood cells multiply and leave memory cells.

Question 11

Platelets?

Answer 11

Small fragments of cells,

No nucleus,

Help clot blood at a wound,

Stop microorganisms getting into the body.

Question 12

Plasma?

Answer 12

Pale, straw coloured liquid,

Carried everything (red and white blood cells, platelets…),

Also carried carbon dioxide from organs to lungs,

Hormones, proteins, antibodies all carried in plasma,

Urea from liver to kidneys.

Question 13

Respiration Definition?

Answer 13

Process of transferring energy from the break down of organic compounds (usually glucose).

Question 14

What Type Of Reaction Is Respiration?

Answer 14

Exothermic.

Question 15

Respiration Types?

Answer 15

Anaerobic or Anaerobic.

Question 16

Aerobic Respiration?

Answer 16

Needs plenty of oxygen for this to happen,

Glucose + Oxygen ——> Carbon Dioxide + Water.

Question 17

Anaerobic Respiration?

Answer 17

This happens when a person performs intense exercise,

Body cannot supply enough oxygen to the muscles,

This respiration is less efficient because it transfers less energy than aerobic respiration,

Glucose is o my partially broken down and lactic acid is produced,

Lactic acid builds up and can cause pain and cramps,

Glucose ——> Lactic Acid.

Question 18

Anaerobic Respiration In Plants?

Answer 18

Glucose ——> Ethanol + Carbon Dioxide,

Ethanol and carbon dioxide build up instead of lactic acid.

Question 19

Double Circulatory System?

Answer 19

This means blood flows around the body using two circuits,

Humans have this.

Question 20

First Circuit?

Answer 20

Deoxygenated blood flows to the lungs to take oxygen in,

Oxygenated blood then returns to the heart.

Question 21

Second Circuit?

Answer 21

Heart pumps oxygenated blood around all the other organs in the body to deliver oxygen to cells,

Deoxygenated blood then returns to the heart.

Question 22

Single Circulatory System?

Answer 22

Deoxygenated blood from body travels to heart which pumps it around the body again,

An example of this system is in a fish.

Question 23

Valves?

Answer 23

Prevent back flow of blood.

Question 24

Cardiac Output Is?

Answer 24

The total volume of blood pumped by a ventricle every minute.

Question 25

Equation For Cardiac Output?

Answer 25

Heart Rate (bpm) x Stroke Volume (cm3).

Question 26

Heart Chambers?

Answer 26

Right Atrium,
Right Ventricle,
Left Atrium,
Left Ventricle.

Question 27

Four Major Blood Vessels?

Answer 27

Vena Cava,
Pulmonary Artery,
Pulmonary Vain,
Aorta.

Question 28

Flow Of Blood Through Heart?

Answer 28

Right atrium receives deoxygenated blood from the body through the Vena Cava,

Blood flows to right ventricle which pumps the blood through the pulmonary artery to get to the lungs,

Blood is oxygenated in lungs,

Left atrium recurved this oxygenated blood through the pulmonary vein,

Left ventricle revives this oxygenated blood. It then pumps it to the rest of body through the aorta.

Question 29

Left Ventricle Features?

Answer 29

Thicker wall than the right ventricle,

This is because it must pump blood around the whole body so there is more muscle in the walls,

The right atrium only pushes blood to the lungs.

Question 30

Calculate Surface Area?

Answer 30

Length x Width

Question 31

Calculating Volume?

Answer 31

Length x Width x Height

Question 32

The Bigger The Organism, The….?

Answer 32

The bigger the organism, the smaller it’s surface area is compared to its volume,

This makes diffusion harder.

Question 33

How White Blood Cells Kill Pathogens?

Answer 33

Pathogens have antigens,

When your B- lymphocytes come across a pathogen with a antigen on it, they start to produce antibodies,

These antibodies bind with the antigens on the pathogen,

They group the pathogens together,

The phagocytes come and engulf the pathogens,

Lymphocyte Memory cells are left behind.

Question 34

Physical Barriers?

Answer 34

Skin - blood clots,

Hairs and Mucus - trap particles,

Cells in Trachea and Bronchi - produce mucus which traps pathogens (cilia).

Question 35

Chemical Barriers?

Answer 35

Stomach - produces hydraulic acid that kills pathogens that are swallowed,

Eyes - produce a chemical called lysozyme (in tears) which kills bacteria on surface of eye.

Question 36

Capillaries Carry?

Answer 36

Red blood cells and plasma.