Organising Animals and Plants

Question 1

Label the heart

Answer 1

bottom left = right ventricle
bottom right = left ventricle
top left = right atrium
top right = left atrium
pulmonary artery middle left takes deoxygenated blood to lungs
aorta middle right carries oxygenated blood around the body
pulmonary vein right brings oxygenated blood from lungs
vena cava left brings deoxygenated blood into heart

Question 2

Stent

Answer 2

Balloon inflated to open vessel
Balloon deflated and removed
Stent remains in place holding vessel open
Blood in coronary artery flows freely
No anaesthetic needed
Can release drugs with stent as well

Question 3

What happens if you have a leaky valve?

Answer 3

Withstand a lot of pressure
May leak or not fully open
Makes you breathless and eventually die without treatment

Question 4

What’s your heart beat controlled by?

Answer 4

Controlled by group of cells found in the right atrium

Question 5

What’s your heart beat controlled by?

Answer 5

Controlled by group of cells found in the right atrium that acts as natural pacemaker

Question 6

What happens if your heart beats too slowly/fast?

Answer 6

too slow = don’t get enough oxygen

too fast = cannot pump properly

Question 7

What does an artificial pacemaker?

Answer 7

Artificial pacemaker sends strong, regular electrical signals to your heart
Stimulating it to beat properly
It’s very sensitive to what your body need and only work when natural rhythm goes wrong
Some stimulate heart to beat faster when you exercise
Need regular medical checks

Question 8

Artificial Hearts Strengths and Weaknesses

Answer 8

Don’t restore person’s health
If heart fails completely, need a transplant
Patients need to wait for a tissue match, some die while waiting for transplant
Temporary hearts = need lots of machinery, stay in hospital until they have transplant
Gives people the chance to like relatively normal life
Gives diseased hearts a rest
Removes strain of keeping the blood circulating
Expensive

Question 9

How does ventilation in the lungs work?

Answer 9

Ventilation moves air in and out maintaining a steep concentration gradient
Ventilation works by the contraction and relaxation of the intercostal muscles between the ribs and diaphragm, changing the pressure inside the chest cavity so air is forced in or out of the lungs as a result of differences in pressure.

Question 10

Process of gas exchange in the lungs

Answer 10

Breathe in → oxygen moves into lungs (maintaining steep concentration gradient with the blood)
Oxygen continually diffuses into bloodstream through surface of alveoli
Breathing out → removes CO2 (maintaining steep concentration gradient)
Carbon dioxide continually diffuses out of bloodstream into the air in the lungs

Question 11

Epidermal Tissue

Answer 11

Protects surface

Waterproof

Question 12

Palisade Mesohyll

Answer 12

Photosynthesis

Question 13

Spongy Mesophyll

Answer 13

Photosynthesis
Big surface area
Diffusion of gasses

Question 14

Xylem

Answer 14

Water and mineral ions from roots → leaves and stem
Via transpiration
Mature xylem cells are dead

Question 15

Phloem

Answer 15

Dissolved food/sugars from leaves → rest of plant (organs and roots)
Via translocation
Provides energy for winter

Question 16

Why do plants need food make by photosynthesis?

Answer 16

Respiration
Production of protein
Movement of water (transpiration and osmosis)
Dissolved mineral ions from roots, growth

Question 17

Why do plants need water?

Answer 17

Photosynthesis
Hold itself upright
Structure

Question 18

What happens when guard cells open stomata process and result?

Answer 18

→ air goes into leaves
→ CO2 diffuses into air spaces and then into cells down concentration gradient
→ this maintains concentration gradient for O2 to diffuse from cells into air

When stomata open:

• Lose water vapour
• Water vapour evaporates from cells lining air spaces
• Pass out leaf by diffusion
• Transpiration

Question 19

What is the transpiration stream?

Answer 19

Water evaporates from surface of leaves
More water pulled up through xylem
Higher evaporation rate = more water

Question 20

Investigating stomata practical

Answer 20

1) Use nail varnish to cover an area of the leaf and peel it off
2) Place peel on microscope slide
3) With an eyepiece graticule, use low magnification and count the number of stomata in a random sample of squares
4) Without an eyepiece graticule, use higher magnification and count the number of stomata in the field of vision and repeat this with a number of sample areas of the peel to collect your data
5) You can calculate the mean number of stomata on a given area of a leaf
6) You can use this to estimate the number of stomata on the whole leaf

Question 21

Factors affecting water loss

Answer 21

Temperature
Humidity
Air movement
Light intensity

Question 22

How does a plant control its water loss

Answer 22

Wilting = reduces available surface area for water loss

Stomata close = prevents most water loss

Question 23

How does light intensity affect transpiration rates?

Answer 23

Increases rate of transpiration

More stomata open for CO2

Question 24

How do weather conditions affect transpiration rates?

Answer 24

Hot, dry, windy
More water evaporates from cells and diffusion is faster
Concentration gradient is steeper

Question 25

How does temperature affect the rate of transpiration?

Answer 25

Molecules move faster
Diffusion occurs more rapidly
Stomata open for gas exchange

Question 26

What are some physical features that affect the rate of transpiration?

Answer 26

Waterproof layer = prevents uncontrolled water loss

Stomata on underside of leaves = protects from direct sunlight