Reproduction in Plants

Asexual reproduction in plants is when plants grow from plant parts.
eg. leaf buds, bulbs, corms, tubers, suckers

Advantages of asexual reproduction:

• grows faster
• adapt well to the existing environment.

Disadvantages of asexual reproduction:

• unable to move to new location
• has the same characterisitics as parents.

Flowers are the reproduction part of a flowering plant and its function is to produce seeds.

After fertilisation, portions of the flower develop into a fruit containing seeds.

Pollination

Fertilisation

Formation and Development of Seeds

Sepal is the green part that protect a flower bud before it opens.

Sepals protect and support the petals.

Petals attract insects and signals that there is nectar in the flower.

Stamen is the male reproductive part that produce pollen grains.

Pistil is the female reproductive part that has unfertilised seeds.

(cross section of the flower)

Stigma - small, sticky pad where pollen grains stick to.

Style - a tube where the pollen grains go down towards the ovary.

Ovary - contains the embryo which grow into seeds once fertilised.

Filament - a slender stem that supports the anther.

Anther - contains plooen sacs where pollen grains are formed.

Pollination is the transfer of pollen from the anthers to the stigma.

Fertilisation is the fusion of nuclei fromt he pollen grain to the stigma.

Methods of pollination:

• Wind
• Insects and Animals

Advantages of seeds dispersal:

• Improving chances of success by reducing compeition and overcrowding.
• enables colonisation of new suitable habitats - increased chance of species survival

Methods of seeds dispersal:

• Water
• Wind
• Animal
• Splitting and Explosive action

Seed dispersal by wind :

• Wing-like structure which has high air resistance

eg. angsana, shorea

• light

eg. grass

• fine hair to enable them to float

eg. lalang

Seed dispersal by water :

• have fibrous fruits and seeds
• can float on water

Seed dispersal by animal :

• seeds which are sticky or have little hooks.

eg. love grass, mimosa

• fleshy and juicy fruits

eg. tomato, guava, rambutan, durain, nuts

Seed dispersal by splitting :

• split open without explosive action

eg. african tulip and kapok

• split open with explosive action

eg. balsam and rubber

Germination takes place in the presence of:

• Water
• Oxygen
• Warmth

Methods of natural vegetative propogation:

1. Leaf buds

eg. bryophyllum begonia

2. Bulbs

eg. onion, garlic

3. Corms

eg. water chestnut

4. Tubers

eg. potato

5. Suckers

eg. banana, pineapple, heliconia