B4 Organisation of animals and plants

Question 1

What is an artery

Answer 1

A blood vessel that carries blood away from the heart at relatively high pressures
It has thick muscular walls and a small lumen

Question 2

What is a capillary

Answer 2

Small thin walled blood vessel that connects arteries to veins
Walls are one cell thick-short diffusion distance

Question 3

What is a vein

Answer 3

Blood vessel that returns blood to the heart at relatively low pressures
Thin walls
Valves
Large lumen

Question 4

What happens in our lungs when we breathe

Answer 4

When breathing in air flows in through the trachea
Through the bronchi to each lung, then to the alveoli
The diaphragm and intercostal muscles contract when we breathe in and relax when we breathe out

Question 5

How are the lungs adapted for efficient gas exchange

Answer 5

Short diffusion pathway
Huge surface area
Good supply of oxygen and blood

Question 6

What are the heart ventricles

Answer 6

The larger chambers in the heart
The right ventricle pumps blood to the lungs
The left ventricle pumps blood to the rest of the body

Question 7

What are the atria (atrium)

Answer 7

The smaller chambers in the heart
These fill with blood from the vena cava and pulmonary vein then pump the blood into the ventricles

Question 8

What is the aorta

Answer 8

The artery leaving the left ventricle
Sends oxygenated blood to the rest of the body

Question 9

What is the vena cava

Answer 9

The main vein that brings deoxygenated blood back to the heart (The right atrium)

Question 10

What is the pulmonary artery

Answer 10

The artery that leaves the right ventricle to carry blood to the lungs

Question 11

What is the pulmonary vein

Answer 11

The vein leading from the lungs back to the heart (left atrium)

Question 12

What are the 4 components of the blood

Answer 12

Red blood cells
White blood cells
Plasma
Platelets

Question 13

What is the plasma and what is its function

Answer 13

The liquid part of the blood which all the blood cells are suspended in
It transports: Carbon dioxide from the organs to the lungs, urea from the liver to the kidneys

Question 14

What are red blood cells and what is there function

Answer 14

Biconcave shaped cells that contain haemoglobin which oxygen can bond to for transportation
Very large surface area for diffusion of gases and can squeeze through capillaries

Question 15

What are white blood cells and what is there function

Answer 15

Cells in the blood that fight infection caused by pathogens-Form part of the bodies immune system
M
Lymphocytes-Synthesise antibodies
Phagocytes-Engulf and digest pathogens

Question 16

What are platelets and what is their function

Answer 16

Fragments of cells
Their role is to initiate the process of clotting at a wound, this blocks the wound in the blood vessel and prevents excess blood loss

Question 16

Where is the hearts natural pacemaker

Answer 16

Right atrium

Question 16

What are the risk factors of Coronary heart disease

Answer 16

Smoking
Obesity
High blood pressure

Question 17

How can CHD be treated

Answer 17

Stents can be used to open up the blood vessel
A metal mesh with a tiny balloon inside is inserted into the artery and the balloon is inflated which opens up the blood vessel and allows the blood to flow freely

Question 18

What happens if your heart valves are damaged

Answer 18

Blood flow is reduced

Question 19

What is the treatment for leaky or damaged valves

Answer 19

Biological valves-Made from valves taken from pigs of cattle
Mechanical valves-Made from polymers and titanium

Question 20

What are the pros and cons of biological valves

Answer 20

Pros-
They do not damage red blood cells
Cons-
Can become hardened after several years
May have to be replaced
Risk pf rejection

Question 21

What are the pros and cons of mechanical valves

Answer 21

Pros-
Strong and durable, wont have to be replaced
Cons-
Damage red blood cells
Require anti clotting drugs for the rest of patients life
Some people say they can hear the valves open and close

Question 22

What is the epidermal

Answer 22

Type of plant tissue that covers the surface of a plant

Question 23

What is the palisade mesophyll

Answer 23

The tissue in the leaf where photosynthesis take place

Question 24

What is the spongy mesophyll

Answer 24

Tissue in the leaf with air spaces between cells-Specialised for gas exchange

Question 25

What are xylem

Answer 25

Narrow tubes in the roots stems and leaves which transport water and mineral ion for the roots to the shootd

Question 26

What are the phloem

Answer 26

Tubes that run along side the xylem but transport sugars dissolved in water-Translocation

Question 27

What are guard cells

Answer 27

Form the stomata on leaves-the holes through which gases are exchanged
They can open and close the stomata as needed

Question 28

What is transpiration

Answer 28

The process by which plants lose water as vapour from their leaves by the stomata

Question 29

What factors increase the rate of transpiration

Answer 29

Higher temperature
Lower humidity(drier air) Steeper conc gradient
Higher air flow(windier)Refreshes conc gradients, water vapour is constantly blown away from the plant
Higher light intensity

Question 30

Why is it useful for guard cells to be able to control the stomata

Answer 30

If the conditions are dry, the guard cells can close the stomata in order to conserve water