Catégories : Tous - pollination - fertilisation - adaptations - wind

par Farah Rizal Il y a 15 années

1573

TLR Plant Reproduction

Pollination is the essential process of transferring pollen from the anther to the stigma, enabling fertilization in plants. This process can be facilitated by insects or wind. Insect pollination involves insects like bees being attracted to flowers by brightly colored petals and enticing scents.

TLR Plant Reproduction

Optimum of each so enzymes work at their best

Plant Reproduction

Fertilisation

Requirements
The nucleus of the male cell must reach the female nucleus of the egg cell, and fuse with it
Gametes

This is the fusion of the two Sex Cells

Female gamete, called the egg cell, is in the ovule

In plants, male gametes is in the pollen grain

Gametes are the sex cells of living organisms

Process 2
4. Embryo grows into mature plant
3. The fertilised egg cell divides many times and form an embryo
2. Nuclei fuse together
1. Male cell and female cell meet
Process 1
3. Nucleus from pollen moves down tube to ovary
2. Pollen tube grows down through the style to ovary
1. Pollen grain lands on stigma
The process by which a male and female sex cell fuse together to form a zygote.
The process by which the male gametes in the pollen grain meets the female gametes in the ovule.
The process following pollination, required if a flower is to produce seeds.

Germination

The Process of a seed growing under the right conditions.
When a leaf manages to reach above soil, it can immediatly start photosynthesising. This can produce food, which will allow the plant to grow more!
When there is the right stimulus, the seed uses its fats, and food reserves to reach the top, and photosynthysize.
The seeds stay dormant, until the right stimulus is used, such as positive geotropism
Conditions
Oxygen: This is vital for the seed to aerobically respire. This makes food, which then allows the seed to grow, and later photosynthesize, when there is a leaf.
Water: There is only about 20% water content in a seed, and in a fully mature plant, there is about 90%
Temperature This is so enzymes can function properly, and therefore speed up biological reactions, such as mitosis
(In a Broad Bean)

2. The epicotyl elongates upwards, and lateral roots develop which are sometimes called secondary roots.

1. the testa splits, and the radicle emerges from the seed.

The process by which a seed grows into a mature plant

e.g. If a seed lands in a suitable place, it will germinate, there are a certain amounts of conditions that need to be met in a seed

Pollination

Types
Wind

Adaptations of the flower

5. Plants have a large surface area which allows them to have more chance to catch pollen on their stigma's

4.Anthers easily shooked by wind, because they are not rigidly attached to the filaments.

3.Have anthers and stigmas which project outside the flower.

2.Pollen grains are light and smooth, giving the ability to travel long distance by moving air.

1.Adapted to produce great amount of pollen so that there is more chance some of the pollen grains can reach the stigma of the flower.

5.The fertilized egg cell develop into an embryo, the ovule becomes the seed and the ovary forms the fruit.

4.The pollen then fertilises with the egg cell inside the ovule.

3.Pollen tube is formed and the pollen goes down to the ovary.

2.It lands on the stigma of the flower.

1.Pollen travels through the wind.

Insect

Adaptation of the flower

3.The 'dark lines' on the petals helps direct the insects to the nectar source.

2.Some produce nectar to also attract insects.

1.Brightly coloured petals and scent attracts insects.

Process

Adaptations of the flower: The petals are scented, the Petals are brightly coloured which attract the insects. They nectar is located at the base of the flower, which makes the insect "dig" for it, making pollen rub off onto the insect

4. The next time the same insect goes to another plant to collect nectar, the ovaries which were stuck to the insect rub off against the stigma, which will allow fertilisation to occur.

3. While it reaches it, some of the ovules made by the ovaries rub off onto the insect.

2. The insect has to reach the nectar, which is at the bottom of the flower.

1. The insects and bees are attracted towards the nectary where sugar is made, and the petals give out scent, and are coloured to attract the insects.

Diagram

Definition
The transfer of pollen from the anthers to the stigma for fertillastion to occur