Osmosis is the net movement of water particles from an area of high water concentration to and area of low water concentration through a semi permeable membrane to reach equilibrium.
1 of 18
Explain the process of active transport.
Active transport allows cells to absorb substances across a semi permeable membrane against the concentration gradient. It therefore requires energy released from respiration.
2 of 18
How do you become dehydrated during exercise?
During exercise your heart rate increases and blood vessels dilate. This causes you to become and therefore more sweat is produced so you can cool down. Mineral ions and water are lost through sweat causing dehydration.
3 of 18
What are sports drinks designed to do?
Sports drinks are solutions of sugar, water and mineral ions. The water rehydrates you and the sugar and mineral ions balance the concentration of body fluids.
4 of 18
Describe the features of an efficient exchange surface.
Large surface area, thin walls and a good blood supply.
5 of 18
Which structures increase the surface area of the lungs?
Alveoli.
6 of 18
What happens in the lungs when we breathe in?
Intercostal muscles contract, the ribcage moves up and out, the diaphragm flattens, the volume of the thorax increases, the pressure in the thorax decreases and air is drawn in.
7 of 18
What happens in the lungs when we breathe out?
Intercostal muscles relax, the ribcage moves down and in, the diaphragm becomes domed, the volume of the thorax decreases, the pressure in the thorax increases and air is forced out.
8 of 18
Why does ventilation occur?
Because of pressure changes inside the chest.
9 of 18
Using an example give advantages and disadvantages of a positive breathing aid.
Bag ventilator; advantages - light weight, small and can be used at home. Disadvantages - interrupts day to day life.
10 of 18
Using an example give advantages and disadvantages of a negative pressure breathing aid.
The iron lung; advantages - it keeps the person alive and keeps their breathing stable. Disadvantages - very uncomfortable and interrupts your life.
11 of 18
Which structures are the exchange surface for food molecules?
Villi.
12 of 18
What does the stomata do?
Allows oxygen out and carbon dioxide into leaves.
13 of 18
How do leaves increase diffusion?
Flat and thin to diffuse quickly, contain internal air spaces which increase area for diffusion to take place.
14 of 18
Explain the movement of water throughout a plant.
Plants take up water through the roots, the water is passed through the plant by the xylem to the leaves where water evaporates and diffuses out through the stomata.
15 of 18
Describe the features of a plant the reduce transpiration.
Waxy cuticles to stop leaves from losing water through diffusion, large surface area of roots to absorb water, ability to wilt so less surface area for diffusion to take place, stomata on the underside to reduce evaporation and stomata can close.
16 of 18
Give an example f when active transport is carried out.
Roots absorb mineral ions.
17 of 18
Why is the rate of transpiration higher on a sunny day?
The plant is photosynthesising at a faster rate and needs more carbon dioxide therefore stomata will open as wide as possible.
18 of 18
Other cards in this set
Card 2
Front
Explain the process of active transport.
Back
Active transport allows cells to absorb substances across a semi permeable membrane against the concentration gradient. It therefore requires energy released from respiration.
Card 3
Front
How do you become dehydrated during exercise?
Back
Card 4
Front
What are sports drinks designed to do?
Back
Card 5
Front
Describe the features of an efficient exchange surface.
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