Friday, 29 April 2011

Plants around school (1)



























Worked with Michelle Huang and Lily A.

Lily Dissection

Apple Dissection

Diagram of an Apple Dissection:

Worked with Yilin Huang
Taken from: http://yilinbiology.blogspot.com/

Tuesday, 26 April 2011

3.4 Plant Fertilisation

3.4 understand that the growth of the pollen tube followed by fertilisation leads to seed and fruit formation
Pollen grains grows pollen tube to the ovule. This tends to be species specific.
The male nucleus travels down the tube to the ovule.
Four things happen:
1.Pollen Nucleus will fertilise the ovule which will lead to the Zygote which will grow into the embryonic plant)
(Pollen nucleus + Ovule ===> Zygote===>Embryonic plant)
2.Outside of the ovule forms the seed coat (TESTA)
3.Formation of Cotelytons (food stores for the seedling that will support the plant until the plant develops its first sets of leaves)
4.Thickening of the walls of the ovary, so the plant will put sugars, protein etc that will build it up, which forms a fruit which is developed from the wall of ovary/carpel.

Here are some examples of fruits and their seeds inside:
Examples of different kinds of seeds:



Fruit on the left and seed on the right:



Monday, 4 April 2011

3.3a Insect Pollination & 3.3b Wind Pollination

3.3a Main Points:
In the process of pollinating a flower, the must be a transfer of pollen from the anthers from to the stigma of another.
Pollen is a small structure which contains the male nuclei.
In a insect pollination the insect carries the pollen from one to another.
In a plant there needs to be adapted to attract insects. They have signals like colour petals and special scent to attract insects.
To some insects there also need to be a value and the flowers provide nectar (food) which is also a source of protein for some insects.
The stamen is the male part of the plant which has the anthers that produce the pollen grains. The female part is composed of stigma, style and ovules (called the Carpel).
3.3b Main points:
One of the adaptation of the pollen grain is that it is light weight and has some type of wing feature to be carried through the wind easily and anthers are sticking out to be exposed to the wind. Third feature is that the stigma has a really large SA, feather-like structure to catch the pollen grains in the wind.
In wind pollinated plants, they are often plants, No colour, No scent, No nectar (no point producing nectar) - No point, only wasting energy for a grass which is a wind pollinated plant