RP 5 Flashcards
Animal dissection some safety precautions.
1.scalpel is sharp
2.wash hands with soap after dissection
3.disinfect equipment
4.cut away from body
5.cut onto hard surface
How atrioventricular valve maintains a unidirectional flow of blood.(2)
1.pressure in LA > LV
2.open and when pressure decreases it closes
How do you return the air bubble to start?
1.open tap
2.add h2o
Precautions when cutting shoot to set up potomoter.
1.cut under water
2.diagonal
3.tap shut
Why return air bubble to start? What ⬆ ? (2)
- allow to take repeat measurements
- increases raliability
How do you prevent water loss?why?
1.use waterproof jelly between shoot and tube
-OIL LAYER
2.no air bubble forms
How would you determine rate of water movement in potometer
? (2)
1.distance moved over time
2.diameter/volume of tube
How would you determine rate of water movement with a balance per group of xylem vessels?(2)
1.change in mass
2.number of xylem vessels
How to improve reliability and accuracy with potometer? (2)
1.repeat with diff species /large number of species
2.use data logger to reduce chance of human error
Controls in potometer experiment? for plant? (4)
1.humidity- WP gradient reduced
2.temp
3.light intensity
4.same size/age/specie
Standardised procedure in potometer. (1)
1.measure rate every 5 mins intervals
Why water has water moved up? (3)
1.evaporation of water/transpiration
2. water potential gradient
3. strong cohesion maintains column
Damage on xylem/ Fewer stomata?
1.damage continous column of water
2.air bubbles form
3.less cohesion
4. less transpiration
Narrower trunk?
-HOTTER ONLY
-experience tension
-negative pressure
-due to cohesion
