4.2 Quadrates

Quadrates are used to estimate the population size of an organism in two different areas.
All ecosystems are made up of a number of populations which formed the community.
The technique is called quadrating, it is based on squares and can be made from an material.
They form square grids which can consist of 0.25 meter or 1 meter.
Quadrates are a method of sampling different locations so populations can be compared in two different locations.

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4.1 Ecosystems

A community of organisms consist of a population of different species.
The habitat includes the non biological factors.
The environment could have the cycle of daylight with dark, the temperature, rainfall, humidity and slope of the land.
All the factors have something in common; they are all non biological.
The community which is made up from different species interact with each other.

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Image: Parts of the Apple (Fertilisation)

Core:

Seeds:

Surrounding of core and leftover stigma and other parts:

Fruit of outside that attracts animal:

3.4 - Plant Fertilisation

-The pollen tubes will only complete if they are from the same species
Pollen grains on stigma - germinate and tube begins to grow downwards
- One tube goes down to ovule - nucleus travels down this tube - into ovule
4 things will happen
1. Pollen nucleus will fertilise the ovule --> formation of zygote --> grown in to embryonic plant
2. outside of ovule forms seed coat (TESTA)
3. Inside formation of seed (cotyledons) - food stores for the seedling -- supports plant until it develops first sets of leaves
4. Thickening of the walls of the ovary/carpel - plant will put energy (sugars, proteins) - will form the fruit - developed from the wall.

Looking at a Plant

3.3b - Wind Pollination

- Transfer of pollen grains from anther by air, then carried by wind to the Stigma.
- Grass - No colour in the petals and no scent to attract insects so no point to produce these, waste of energy when it is a wind pollinated plant.
- Anthers hang well clear of any basic flower structure, so exposed to the wind.
- Stigma, really large surface area, feather like structure to catch pollen grains.
- Probably moves more efficiently through the air.

3.3a - Insect Pollination

- A pollination flower transfers pollen grain from the anther to a stigma of a plant.
- A pollen is a small structure that contains male nuclei.
- Transfer in an insects pollinated plant is taken place by insects.
- Its necessary for this plant to attract insects.
- If pollen goes from one plant to another this is called cross pollination.

Structure - Petals
- Stamen (male part of the plant) - Anther (pollen grains), Filament
- Carpel (female Part of the plant) - Stigma, Style and Ovary (ovules)