B4- Organisation in animals and plants Flashcards
What 4 things make up blood?
Platelets, red blood cells, white blood cells, plasma
Function of white blood cells?
Function and adaptation of phagocytes?
Protect the body against infection
*Engulf, digest and destroy bacteria
“Very flexible, contains enzymes
Function of white blood cells?
Function and adaptation of lymphocytes?
Protect the body against infection
*Produce antibodies or antitoxins
“Neutralises harmful poisons
Function and adaptation of red blood cells
*Carry oxygen around the body
“No nucleus more space for haemoglobin, biconcave shape high SA diffusion, carries haemoglobin for oxygen to bind to
Function and adaptation of platelets
*To help blood clot at a wound
“Small fragments of cells, no nucleus
Function and adaptation of plasma
*Carry blood cells and other substances around the body
“A liquid
Circulatory system
Function?
Consists of?
To transport substances around the body. Consists of blood, blood vessels and heart
3 types of blood vessels
Arteries, veins, capillaries
Arteries
Function?
3 Features?
Carry blood away from heart to other organs
-Thick walls withstand high blood pressure
-Thick elastic fibres stretch and return to normal size
-Narrow lumen creates high blood pressure
Veins
Function?
3 Features?
Carry blood to heart
-Thin outer walls as lower pressure
-Valves prevent back flow
-Large lumen for slow flow of blood
Capillaries
Function?
3 Features?
Allow gas exchange
-Capillary bed has large sa for faster diffusion
-Walls 1 cell thick for faster diffusion
-Narrow lumen
Describe the movement of blood through the heart
Deoxygenated blood-vena cava-right atrium-right ventricle-pulmonary artery.
Oxygenated blood-pulmonary vein-left atrium-left ventricle-aorta
Double circulatory system
One system carries blood between heart and lungs. Other system carries blood between heart and rest of body
Which vessels supply blood to the heart?
Coronary artery
Where are pacemaker cells found?
Right atrium
What do valves do?
Prevent the backflow of blood, keep it in the right direction
Which ventricle has thicker muscle wall and why?
Left ventricle to develop pressure to carry blood to the body
Calculation for cardiac output
Cardiac output (ml/min) = stroke volume (ml/beat) x heart rate(bpm)
Irregular heart rate Treatment?
How?
Ad?
Dis?
Artificial pacemaker
Electrical device sends impulses so heart contracts
-No side effects, fast recovery
-Requires surgery, affected by electromagnetic fields
Faulty valves (natural)
Treatment?
How?
Ad?
Dis?
Biological valves
Replaces with animal or human valves, blood flows in one direction
-No back flow of blood or medication required
-Need to be replaced, can harden overtime
Faulty valves (unnatural)
Treatment?
How?
Ad?
Dis?
Mechanical valves
Replace with metal valves, blood flows in one direction
-Long lasting, strong,
-Can cause blood clots, need medication for this
Heart failure treatment (short term)
Treatment?
How?
Ad?
Dis?
Artificial heart
Pump in chest, controlled by machine
-No tissue damage, short term solution
-Can cause blood clotting, needs surgery
Heart failure treatment
(long term)
Treatment?
How?
Ad?
Dis?
Donor heart transplant
Healthier donor heart replaces failing one
-Good survival, long term solution
-Long waiting list, long recovery
Coronary heart disease
(pills)
What?
How?
Ad?
Dis?
Statins
Slow rate of fatty deposits
-Reduce chance of heart attack
-Taken for life, small side effects, could forget
Coronary heart disease
(surgery)
What?
Ads?
Dis?
Stent
Balloon inflates in artery to widen it, metal mesh holds it open
-Short recovery time, relieves symptoms
-Risk of allergic reaction, could damage artery
What is coronary heart disease and why is it dangerous?
When the arteries that supply blood to the heart become narrow, due to a build up of fatty deposits. Causes less blood supply to heart, less oxygen to heart, harder to contract, could cause a heart attack.
What gases diffuse to where when breathing in and out
Breathing in- oxygen diffuses out of lungs into blood
Breathing out- carbon dioxide diffuses out of blood into lungs
Where are the trachea, bronchi, bronchioles, alveoli and intercostal muscles found?
Trachea- windpipe (throat)
Bronchi- two branches from trachea
Bronchioles- smaller branches from bronchi
Alveoli- air sacs at end on bronchioles
Intercostal- outside lungs, close to ribs
What happens during inhalation?
Intercostal muscles contract
Diaphragm contracts downwards
Ribs move up and out
Lung volume increases
Lung pressure decrease
What happens during exhalation?
Intercostal muscles relax
Diaphragm relaxes upwards
Ribs move down and in
Lung volume decreases
Lung pressure increases
5 adaptations of alveoli
-In clusters, large sa
-Blood supply from capillaries, steep conc gradient
-1 cell thick lining, short diff distance
-Constant ventilation, steep conc gradient
-Moist lining, dissolve gases
Plant organ system
Consists of?
Function?
Roots, stem and leaves
Transport substances around the plant
Meristem tissue
Function&Adapts
Differentiate into any type of cell
Found in growing tips of roots and shoots
Epidermal tissue
Function&Adapts
Covers surface and protects it
Secretes waxy substance to waterproof leaf, transparent, thin to allow light
Palisade mesophyll
Function&Adapts
Photosynthesis
Upper leaf, close to sunlight, column shaped so high sa to absorb light, chloroplasts to absorb light
Spongy mesophyll
Function&Adapt
Make diffusion efficient
Thin membrane so short diffusion pathway, irregular shape to increase sa, loosely packed with air spaces for gas exchange
Stomata and Guard cells
Function&Adapt
Allows air in to diffuse carbon dioxide in and oxygen out
Small opening over leaf’s surface
Xylem
Function&Adapt
Carry water & mineral ions from roots to leaves
Dead cells with lignin create hollow, strong tube, no end walls, impermeable to water
Phloem
Function&Adapt
Carries dissolved food (amino acids) from leaves to growing parts, storage organs
Sieve plates so water moves more freely, mitochondria for energy, living cells
Differences between phloem and xylem?
6 for each
Phloem: transport food (sugars); travels up and down; living cells; requires energy (has mitochondria); has sieve plates; no lignin
Xylem: transport water and mineral ions; only upwards; dead cells; no energy required; no end walls; lignin for support
Transpiration
The rate of evaporation of water from the leaf
Translocation
Movement of food molecules through the phloem to the plant
Transpiration stream
Movement of water around a plant
How to calculate number of stomata in given area
- Calculate area of field view
- Count no. of stomata in given area
- Divide no. of stomata by area
4 factors that affect rate of transpiration
Temperature, humidity, wind, light intensity
How does temperature affect transpiration?
KE of water increases, molecules move faster, increase transpiration
How does humidity affect transpiration?
Lower conc gradient between inside and outside of leaf, reduces rate
How does wind affect transpiration?
Takes water away from outside of leaf, steep conc gradient, increases rate
How does light intensity affect transpiration?
Guard cells open stomata to take in CO2, when open more water is lost, increases rate
3 ways plants control water loss
Waxy cuticle- waterproof layer
Wilting- drooping leaves, reduces sa&evaporation
Stomata- closed by guard cells
What does a potometer show?
Shows uptake of water by a plant, represents water lost by transpiration
How does a potometer work?
Water evaporates from shoot and drawn through stem through capillary tube. Faster air bubble moves, faster transpiration
