niche spec

define tissue

group of similar cells that work together to perform a specific function

what factors affect the movement of substances

• surface area to volume ratio

• distance

• temperature

• concentration gradient

source of carbohydrates

pasta, rice, bread

source of lipids

butter, oil

source of vitamin A

liver, spinach, eggs

sources of vitamin c

oranges, lemons

sources of vitamin d

eggs, fish

sources of calcium

milk, cheese

source of iron

red meat

source of fibre

bread, fruit

function of mouth

• salivary glands produce amylase

• teeth break down food

function of oesophagus

muscular tube that connects mouth to the stomach

function of stomach

• pummels food with muscular walls

• produces pepsin

• produces HCl - kills bacteria, optimum enzyme for pepsin

function of small intestine

• secretes enzymes

• nutrients are absorbed into the bloodstream

function of duodenum

• digestion

• neutralises stomach acid

function of ileum

absorption

function of large intestine (colon)

excess water is absorbed from the food

function of rectum

faeces are stored

function of pancreas

produces enzymes and secretes into the small intestine

what does ATP do

broken down to release energy

intercostal muscles in inhalation

contract

intercostal muscles in exhalation

relax

alveoli adaptations for gas exchange (5)

• large surface area

• moist lining for gases to dissolve in

• thin walls - one cell thick to decrease diffusion distance

• good blood supply - high concentration gradient

• permeable walls - diffuse easily

excretory products of the kidneys

• urea

• salts

• water

excretory products of the skin

water

salts

urea

what do seeds use until the seedling can carry out photosynthesis

food reserves

what does the nucleus of a cell contain

chromosomes on which genes are located

define mutation

a random change in genetic material that can be inherited