B4 Organising Animals And Plants

Question 1

Functions of blood?

Answer 1

They protect the body from pathogens.
Carry oxygen to build cells through the red blood cells.
Carries carbon dioxide away from the bodies cells.
Carries nutrients to the cells for function and growth.
Carries the waste product urea to be excreted by the kidneys.

Question 2

What does blood contain?

Answer 2

Mainly:
55% plasma
1% white blood cells and platelets
45% red blood cells

Question 3

What is plasma?

Answer 3

It is a yellow liquid that transports all your blood cells and other substances round the body.
Carries carbon dioxide waste to the lungs.
Urea from the liver is taken to the kidneys by plasma.
Small soluble products of digestion pass into the plasma from the small intestines.

Question 4

What does plasma contain?

Answer 4

Water, urea, carbon dioxide, glucose

Not oxygen as it is carried by oxygen not plasma

Question 5

What are red blood cells?

Answer 5

Are biconcave discs that have an increase in surface area to volume ratio for diffusion.
Have a red pigment called haemoglobin.
Have no nucleus making space for haemoglobin.

Question 6

What are white blood cells?

Answer 6

They are bigger than red blood cells but a lot less of them.
They have a nucleus and form part of the body’s defence system.
Can form antibodies against microorganisms and some form antibodies against poison. Other white blood cells engulf and digest invading bacteria and viruses.

Question 7

What are platelets?

Answer 7

Small fragments of cells and have no nucleus.

Gets the blood to clot at a wound and stops you bleeding to death or bringing in bacteria into the body.

Question 8

What are arteries?

Answer 8

They carry blood away from the heart to the organs of your body.
Stretch to get the blood through them and back into shape after.
Have thick walls to withstand the pressure from the heart and blood.
Dangerous if an artery is cut as a lot of blood would come out.

Question 9

What is a vein?

Answer 9

Carries blood away from the organs towards your heart.
Have thinner walls as not as much pressure. Heart valves are to prevent back flow of blood.
The valves open as the blood flows through them towards the heart.
The valves close of the blood flow backwards and squeezed back towards the heart.

Question 10

What are capillaries?

Answer 10

Form a large network of tiny vessels linking the arteries and the veins.
Have very thin walls so substances like oxygen and glucose diffuse easily out of your blood into the cells.
Substances produced by cells pass easily into the blood though capillaries.

Question 11

What happens to blood in the heart?

Answer 11

The blood that enters the top chamber of your heart called the atria.
Blood in your right atrium is deoxygenated blood from the body.
Blood coming into the left atrium in the pulmonary vein is oxygenated blood from the lungs.
The atria contracts together and forces blood down the ventricles.

Question 12

Where does the blood go from the right ventricle?

Answer 12

Right ventricle»» deoxygenated blood»»> pulmonary artery»» lungs

Question 13

Where does the blood go from the left ventricle?

Answer 13

Left ventricle»» oxygenated blood&raquo_space;»> artery called the aorta»» round the body

Question 14

Why is the left ventricle thicker than the right?

Answer 14

It gives the left the pressure needed to force the blood through the arterial system.

Question 15

What do coronary arteries do?

Answer 15

Supply oxygenated blood to the heart by branching off the aorta and surrounding the heart.

Question 16

What do stents do?

Answer 16

When there is fatty materials building up in the arteries blood flow becomes restricted so stents are inserted into arteries and helps keep them opens so blood can pass through them to the heart.
They have a metal mesh that is placed in the artery and inflated to open the vessel and move the fatty materials.

Question 17

What does statin do?

Answer 17

This reduces blood cholesterol levels and slows down the rate of reaction of fatty materials being deposited in the coronary arteries. This reduces strokes and heart attacks from occurring as much.

Question 18

What are biological and mechanical valves?

Answer 18

Mechanical valves are made of materials such as titanium. These last a long time but should take medication to stop blood clots around them
Biological valves are valves taken from animals and put inside to replace faulty or leaky valves. They don’t need medication but usually only work for 12-15 years.

Question 19

What are artificial pacemakers?

Answer 19

This is an electronic device that corrects any irregularities in the heart rate. They are very light and are attached to two wires to the heart. The wires send electrical signals to the heart to make the heart work correctly.

Question 20

What is an artificial heart?

Answer 20

These temporary hearts support your heart until replaced. This heart gives people a chance to have a relatively normal life but may have to stay in hospital for a while. The artificial heart can give a diseased heart a rest to recover. It removes the strain of keeping the blood circulating for a few weeks.

Question 21

Process of breathing in:

Answer 21

Ribs move up and out and the diaphragm flattens, the volume of the chest increases.
Increased volume means lower pressure in the chest.
Atmospheric air is at a higher pressure than the chest so air is brought into the lungs.

Question 22

Process of breathing out:

Answer 22

Ribs fall and diaphragm moves up, the volume of the chest gets smaller.
A decreased volume means increased pressure in the chest.
The pressure is higher in the chest so air is forced out of the lungs.

Question 23

Adaptations of the gas exchange:

Answer 23

Increased surface area in the alveoli- this makes the most effective diffusion of oxygen and CO2.
Thin walls in the cell walls- they are one cell thick and allows diffusion to take place over the shortest distance.
Increase blood supply in the capillaries- maintains a concentration gradient in both directions.
Moist- easier for gas to dissolve.

Question 24

What is the epidermal tissue?

Answer 24

This covers the surfaces to protect the plant. Stops infection and is waxy so waterproofs the leaf.

Question 25

What is the palisade mesophyll tissue?

Answer 25

Contains a lot of chloroplast to carry out photosynthesis.

Question 26

What is the spongy mesophyll tissue?

Answer 26

Has chloroplast for photosynthesis but air spaces and a large surface area for diffusion in gases easier.

Question 27

What is the xylem tissue?

Answer 27

Carries water and dissolved mineral ions from the roots to the leaves. Thick cellulose cell wall with a hollow lumen.

Question 28

What is the phloem tissue?

Answer 28

Carries dissolved food from the leaves to the rest of the plant. They are columns of living cells.

Question 29

What is the meristem tissue?

Answer 29

At the growing tips of roots and shoots. Made up of dividing plant cells that grow and differentiate into all the other cells. They are filled with stem cells.

Question 30

What does the root, stems and leaves form?

Answer 30

An organ system for the transport of substances around the body.

Question 31

What is translocation?

Answer 31

The movement of dissolved sugars from the leaves to the rest of the plant.

Question 32

What is transpiration?

Answer 32

The evaporation of water from the aerial parts of plants

Question 33

What happens when the stomata opens?

Answer 33

Carbon dioxide from the atmosphere diffuses into the air spaces. Oxygen is removed from the leaf by diffusion into the surrounding air. Plants lose water vapour through it as well.

Question 34

Steps of transpiration in plants:

Answer 34

• Water moves into the roots by osmosis.
• Water moves up the stems from the roots.
• Water moves to the leaves from the stems to replace the water lost in evaporation.
• Water is lost from leaves by evaporation through the open stomata.

Question 35

How does light intensity effect transpiration?

Answer 35

When it is light photosynthesis happens faster meaning the stomata would be open for Co2 to enter. This means water can exit the plant easier. But when it is dark the opposite happens. The stomata is closed much more and less water exits.

Question 36

How does air currents and humidity affect transpiration?

Answer 36

There is more water particles outside the plant meaning there is a high concentration of water particles outside and inside the leaf. Diffusion would happen less unless there is a good air current that takes the water vapour away meaning a lower concentration outside and drier than humid and making diffusion easier and much more efficient.

Question 37

How does temperature affect transpiration?

Answer 37

When its warm water particles have more energy than when its colder. With more energy this means it is easier for water to evaporate and diffuse out the plant.

Question 38

What happens to water in the plant?

Answer 38

Most of it is lost in transpiration but some of it is used for things like photosynthesis.

Question 39

How does Immune response work?

Answer 39

• Vaccine is inactive
• Stimulates antibody production
• Stimulates antitoxins production by the white blood cells
• The white blood cells produce antibodies to kill the pathogen
• Antitoxins are formed to neutralise the poisons from virus’
• Antibodies are formed after being infected gain by the disease
• White blood cells engulf the pathogen when attacked.