(I)GCSE Topic 4.3 Quadrates Samples

Use of Quadrates as a Technique for sampling the distribution of organisms in their habitats:
- Use the Quadrate technique to sample the population (Daisy) in a area.

The sample has to be:
- picked at random so there is no Bias.
- representative - has to be a large amount so the estimate of the population has to be as close to the true population as possible.
- The bigger the number of representative sample, the better.
- 10 quadrates / 10% of the actual area

Estimate the population of (Daisys) in the field:
Compare te number of (Daisys) in two or more different areas:

Add up the number of (Daisys) per m2, divide by the number of quadrates, = number of (Daisys) per m2 

(I)GCSE Topic 4.2 Quadrates

- Quadrates are used to estimate the population size of an organism in two different areas.
- First thing you need to do is count the number of individuals in the population.
- Quadrating is based on squares and these squares can be made up of anything including wood, string, or metal.
- Grids can measure from 0.25m up to 1m
- The Quadrate is used to sample the area. You can take a sample from an area and count the number of individuals inside the area and this would be repeated a number of times to gain an estimate of the population size

-Quadrates are a method of sampling different locations so that populations can be compared within the two different locations.

(I)GCSE Topic 4.1 Ecosystems

-Habitat refers to
  - Daylight/dark
  - Temperature
  - Rainfall
  - Humidity
  - Slope of the land

-Community refers to
  - Population - number of individuals if each species
  - Species - breeding fertile offspring
  - Interacting - feeding (food chains/ food webs)

-Community of organisms is made up of a population of different species interacting.
  - Population of different species is the number of individuals of a particular species.
  - Interacting if the feeding of the animals.
  - Species is the organisms which reproduce to give fertile offspring.

SUMMARY
-Ecosystem is a community of organisms in a particular habitat.
-The community is made up of different populations of the different species interacting within that habitat.

TOPIC 4 (I)GCSE ECOLOGY

(I)GCSE Topic 3.4 Plant Fertilisation

-When the pollen grain lands on the Stigma, it travels down the pollen tube and enters the ovule.
-When the pollen grain fertilises with the ovule;
- Zygote will form and later the Zygotes will later divide and turn into an embryo.
- Seed coat called the Testa will form outside of the ovule.
- Cotyledons form inside the ovary, the Cotyledons store food for the seedlings.
- The wall of the ovary thickens because it starts to store foods such as protein, sugars etc. and starts to form a fruit.

(I)GCSE Topic 3.3 b) Wind Pollination

-Transfer of the pollen grain from the Anther to the Stigma through air, carried by the wind.

-Light weight pollen grains with a feature which allows them to move through the air more efficiently.

-Anthers will hang well clear over the basic flower structure so that they are exposed to the wind.

-Stigma have really large surface areas with a feature-like structure to catch the pollen grains as they pass through the air on the wind.

-No coulor, no scent, no nectaries needed to attract insects because they are wind pollinated.

(I)GCSE Topic 3.3 a) Insect-Pollination

-In the process of pollination, there has to be a transfer of pollen grains from the anthers of a flower to the stigma of another.

-Pollen is a small structure of the plant which contains the male neuclei.

-The transfer of Insect Pollination takes place by Insects. And so it is neccessary for the insect to be attracted by the first flower and have a reason to go into the second flower.

-The pollen of one plant going into another is called 'Cross Polination'.

-Things attracting the Insects: coloured petals, Scents, Value to the insect for going to the plant is food which is fructose/nectaties.

-Stamen is the male part of the plant which produces the pollen granes. The anther and the fillament form the stamen.

-The female part of the plant contains Stigme, Style, Ovary. This whole structure is called the CARPOL.