Fucked Flashcards
Excretion
Elimination of metabolic wastes proces
defecation
Removal Undigested food processes (Faeces through the anus)
Sieve Tube
Long Thin phloem cells that have large pores through cell walls at both ends
NO nuclei, mitochondria
Companion Cells
Found alongside sieve tubes
Has nucleus
Controls activity of sieve tube cells
Transpiration
Loss of water vapour by evaporation from surface of a plant through stoma
- Once stoma opens continuous stream of water rises through the plant.
Factors increase Transpiration
Increase in Diffusion Gradient
Increase access to Light
Increase temperature
Factors decreasing Transpiration
Concentration of water vapour
Decrease diffusion gradient
Vascular Plants gas exchange
Root hair with large surface area, absorbs water and nutrients
water is absorbed through Osmosis. allowing dissolved ions to b absorbed by diffusion
Force of water entering roots creates pressure
ADhesion
Adhesion forces of attraction between water molecules and molecules which make up xylem vessels
Cohesion
forces of attraction between water molecules help to pull water up the narrow xylem vessel
Capillary action
Combination Of Adhesion and Cohesion forces allow water to flow UP narrow spaces against gravity
Translocation
Active movement of soluble sugars (photosynthesis) through the phloem of vascular plants from source to sink
- Occurs in multidirectional
- Transported AGAINst concentration gradient
- active transport
Rates affecting translocation
Pressure and concentration gradient
Gas exchange Req
Moist skin
Thin and permeable
Large surface to volume ratio
Constant flow of gases
Highly Vascularised
Greater concentration of req gas
WHY DO PLANTS NOT NEED VENTILATION MECHANISM
Due to their leaves highly exposed to gases/air. This allows air/gases to be constantly replaced. And ALSO since CO2 isnt bad for them as it req for photosynthesis
Stages OF heartbeat
- Heart muscles are relaxed and valves closed, allows blood to flow into atria
- Atria Contracts squeezing blood into ventricles (Atrioventricular valves close preventing backflow of blood
- Immediately ventricles contract and blood is squeezed again leading blood out of the heart
- Once ventricles are empty valves leading out the heart close and muscles relax
Lub Dub explaination
The “lub” is caused by
the closing of the valves leading to the ventricles.
The “dub” is caused by
the closing of the valves
leading out of the heart
Guard cells
Pair of cells which open and close stma to control exit and entry of gases and water
changes in water in guard cells causes them to change shape
how do guard cells open
Guard cells swell with water becoming turgid which bends and draws the cells away from each other allowing gas exchange.
How to guard cells CLose
When guard cells lack of water they become flaccid this causes them to close.
Stoma
Tiny openings in the surface of a plant leaf through which gases can exit and enter
Shoot System
Transport resources
Absorption of oxygen
reproduction
Carries out photosynthesis IN leaves
Root System
Anchors plant
Absorbing water and nutrient from soils
Nutrients in for of dissolved Ions via diffusion.
