4.1 Ecosystems

A community of organisms consist of a population of different species.
Habitat includes all the "Abiotic" factors (non biological factors) for example daylight, temp, rainfall, humidity, slope.
Population is the number of individuals of a particular species.
They are all non- biological. 

3.4 Plant Fertilisation: Understand that the growth of the pollen tube followed by fertilization leads to seed and fruit formations.

• Pollen grains (on stigma) they germinate. 
• The pollen tubes the nuclease travels down into the ovule. In other words pollen nuclease will fertilized the ovule which will form zygote which will grow into the abronia plant. 
• Outside of the ovule forms the seed coat which is call TESTA.
• Inside of the ovule we also cotyledons which stored food for the seedings. 
• The thickening of the wall which protects the ovary where the plants will put a lot of energy such as sugar, protein and built this up and this will form the fruit which is develop from the wall of the ovary or the carpal. 

Structure of a flower

3.3b: Describe the structures of an insect-pollinated and wind- pollinated flower and explain how each is adapted for pollination.

• Transfers of the pollen grain from the anther to the stigma (through air and wind)
• These process will not occur if it does not consist of the following:
• Light pollen
• Anthers will hang well clear (Expose to the wind)
• Relates to the stigma (catch the pollen grain in the air trough the wind) 

3.3a: Describe the structures of an insect-pollinated and wind-pollinated flower and explain how each is adapted for pollination.

• Pollination of a flower has to be transfer of pollen grains from the anther to the stigma of the other.
• Pollen is a male plant. These processes are transfer by insect. By the flowers attract the insect.
• If pollen goes trough one plant to another this is call cross-pollination.
• Flowers can attract insects by:
• Signal (colour petal) 
• Scent (detected molecule)
• Value (produce sugar called fructose)
• Pollen it self as a source of protein.

2.81 Phototropism: Describing Positive phototropism of stems

Photo referring to light.

Tropism referred to growth in response to light. Positive suggest that the growth is towards the light.

Light comes in from all direction therefore it will grow forwards.

If the light comes from the side (lateral) then the plants will bends in the growth towards the lights. (This is an example of positive tropism growth of the stems towards the lights) the light will then moves to the opposite side. This is know as  auxin which causes more growth. 

2.80 Geotropism: describing the geotropic responses of roots and stems

Geotropic referred to gravity and growth responses.
An embryonic root grows downward. This process is called Positive geotropism.
An embryonic roots grows upward is called Negative Geotropism
Shoots grow upwards and the roots grow downwards.