Studying the Seed

The edible part of the apple is the ovary wall. As a pay off to the animals that eat the apple, it contains nutrients.

The animal then eliminates the waste, including the apple seed. The seed then begins to grow into another apple tree

The edible part of the apple is called the testa. This protects the seed and the cotyledons.

The colour of the apple attracts animals to eat it.

3.4 Plant Fertilisation

1. The growth of the pollen tube is followed by fertilisation and soon leads to seed and fruit formation.

2. When the pollen grain lands on the stigma, it begins to germinate and a tube begins to grow down to the ovule.

3. Germination is usually only species specific.

4. The nucleus is then transferred through the tube down to the ovule, thus fertilizing it.

5. Pollen Nucleus + Ovule ---------> zygote/ Embryo

6. Outside of the ovule, a seed coat is formed, this is called the TESTA

7. Inside the seed coat, cotyledons are formed, these food stores for the seedling. This supports the plant until it develops its first set of leaves.

8. The plant uses a lot of its energy (sugars, protein) to thicken the walls of the ovary. This will soon develop to be a fruit that has been developed from the wall of the ovary (carpel)

Reproduction Pollen Tubes In Plants. Germination

Plant Adaptations

Adaptation

Adaptations are changes happening quickly.

Lily’s:

· The sepals have changed or mutated their appearance to look like the petals so it might mean that there is a greater chance of insects getting attracted to it.

· By the plants changing colour, this might mean that insects are able to see colour. The petals give a signal to the insects of whereabouts the nectar is. The plants also give a scent to attract.

· The bee gets attracted to the flower and when going to others, it spreads the pollen.

· The vector for this pollination is insects.

Grass:

· Grass does not produce energy to make scents or pretty petals because they only rely on wind to transfer their pollen.

· One disadvantage is that their reproductive strategy is very risky. There is a very low chance of its pollen being brought to another plant through wind.

· It also has a low chance of catching any pollen.

· The vector for this pollination is wind.

Parts Of A Flower

3.3b Wind Pollination

1. The pollen grains transfer from the anther to the stigma through air carried by the wind

Adaptations:

2. Light weight

3. Wing Feature

3. The anthers are exposed so that they are able to catch the wind

4. The stigmas have a very large surface so that they are able to catch the pollen grains more easily.

5. There is no colour in the petals because it does not need to attract the insects. It also does not have a scent or any nectories as this would just be a waste of energy

- In the process of pollination, there has to be a transfer from the anthers of one plant to the stigma of another

- Pollen is a small structure which contains the nuclei.

- This is done by insects because they are attracted to the flower, causing the pollen to get transferred by the insect to another plant. This is called cross - pollination.

- The adaptations to attract insects are firstly, Signals. The colour in the petals attract the insects.

- The insects are also attracted through the different Scents that the flower gives off.

- The plant also has a Valve that creates fructose, this attracts that flower and acts as pollen protein.

The Carpel is the Female part and the Stamen is the Male part