Biology GCSE B3 (i)

Diffusion - When particles move from an area of high concentration to an area of low concentrations

Osmosis - similar but only refers to water

Active transport - From low concentration to high concentration

Structure of leaves - exchange surfaces are ADAPTED to maximise effectiveness

+ Underneath of leaf is covered in stomata

+ Guard cells control water loss

+ Flat shape increases surface area

Breathing system

Lungs are in THORAX

separated from rest of body by diaphragm 

trachea-Bronchi-Bronchioles-Alveoli

Diffusion through cell membranes

Gas exchange - Oxygen into alveoli and diffuses into blood, Co2 diffuses out of blood and into alveoli, and out of body when you exhale

Adaptations - large surface area, moist lining, thin walls, copious blood supply 

Villi - Network of capillaries give a copious blood supply,

Active trasport - lower to higher concentration

+ root hairs- Large surface area

ACTIVE TRANSPORT NEEDS ENERGY FROM RESPIRATION

+glucose into the gut

Circulatory system

1 heart is two pumps, right side-deoxygenated blood to lungs left side- oxygenated blood around body

2 arteries - away from heart, high pressure

3 Veins - to heart

4 pulmonary artery and pulmonary vein only exception

5 Arteries split off into thousands of capillaries which take blood to every cell

6 Veins carry…