Organising Animals and Plants Flashcards
Label the heart
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
Stent
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
What happens if you have a leaky valve?
Withstand a lot of pressure
May leak or not fully open
Makes you breathless and eventually die without treatment
What’s your heart beat controlled by?
Controlled by group of cells found in the right atrium
What’s your heart beat controlled by?
Controlled by group of cells found in the right atrium that acts as natural pacemaker
What happens if your heart beats too slowly/fast?
too slow = don’t get enough oxygen
too fast = cannot pump properly
What does an artificial pacemaker?
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
Artificial Hearts Strengths and Weaknesses
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
How does ventilation in the lungs work?
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.
Process of gas exchange in the lungs
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
Epidermal Tissue
Protects surface
Waterproof
Palisade Mesohyll
Photosynthesis
Spongy Mesophyll
Photosynthesis
Big surface area
Diffusion of gasses
Xylem
Water and mineral ions from roots → leaves and stem
Via transpiration
Mature xylem cells are dead
Phloem
Dissolved food/sugars from leaves → rest of plant (organs and roots)
Via translocation
Provides energy for winter
Why do plants need food make by photosynthesis?
Respiration
Production of protein
Movement of water (transpiration and osmosis)
Dissolved mineral ions from roots, growth
Why do plants need water?
Photosynthesis
Hold itself upright
Structure
What happens when guard cells open stomata process and result?
→ 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
What is the transpiration stream?
Water evaporates from surface of leaves
More water pulled up through xylem
Higher evaporation rate = more water
Investigating stomata practical
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
Factors affecting water loss
Temperature
Humidity
Air movement
Light intensity
How does a plant control its water loss
Wilting = reduces available surface area for water loss
Stomata close = prevents most water loss
How does light intensity affect transpiration rates?
Increases rate of transpiration
More stomata open for CO2
How do weather conditions affect transpiration rates?
Hot, dry, windy
More water evaporates from cells and diffusion is faster
Concentration gradient is steeper
How does temperature affect the rate of transpiration?
Molecules move faster
Diffusion occurs more rapidly
Stomata open for gas exchange
What are some physical features that affect the rate of transpiration?
Waterproof layer = prevents uncontrolled water loss
Stomata on underside of leaves = protects from direct sunlight
