BIO 02 Lesson 5: Plant Reproduction

Sexual Reproduction

Is the generation of genetically varied offspring from two parents.

Asexual Reproduction

Occurs when a produced offspring is genetically identical to the sole parent.

1.Pollination

2.Fertilization

3.Seed Dispersal

4.Germination

Steps of Sexual Reproduction in Plants

Pollination

The act of transferring pollen grains from the male anther of a flower to the female stigma. The goal of every living organism, including plants, is to create offspring for the next generation.

Self-pollination

happens when a plant's own pollen fertilizes its own ovules.

Cross-pollination

happens when the wind or animals, insects move pollen from one plant to another.

STIGMA

- Female reproductive organ

- part of the flower that "receives the pollen grains"

POLLENS

- "fine powders" that contains male reproductive cells (requirement for sexual reproduction in plants)

- Produced by anther

Anther

the part of a stamen that contains the pollen.

Filament

Supports the anther

Stigma

a tube grows down the style and enters the ovary.

During the process of fertilization, pollen lands on

Ovule

A structure that develops within the ovary of a seed plant and contains the female gametophyte.

Has ovules that contain female gamete

Style

Links the stigma to the ovary

Stamen

Male sex organs

Carpel

Female sex organs A flower can have one or more --------. All the ----------- together are termed gynoecium or pistil. A pistil may contain a single -------- or multiple --------- fused together.

Petal

Brightly colored and scented structure

Sepal

Green leaf-like structure that protect the flower in bud stage

Calyx

the collective name for the sepals of a flower.

Corolla

the petals of a flower, considered as a unit.

FERTILIZATION

Pollen lands on stigma

Tube grows down the style and enters the ovary

• After successfully landing on the stigma of flower of the same species, pollen start to germinate.

• Pollen grains absorb sugary solution from the stigma.

• Pollen germinates to produce a pollen tube.

• The pollen tube grows down the style of the carpel.

Growing pollen tube carry male gametes (Sperm)

• The pollen tube complete its growth by entering an opening in the ovule.

• The male gamete moves from the tube to fuse with the egg (in ovule)

FERTILIZATION

Formation of fruit

After fertilization the ovary wall develops into fruits. Ovary wall may be fleshy (plum)or dry pod (pea)

SEEDS

The product of sexual reproduction are _________

Seed Dispersal

The adaptive mechanism in seed-bearing plants, involving the movement or transport of seeds away from the parent plant to ensure their germination. It is commonly known as the 'scattering of seed'.

1. Space,

2. Light,

3. Nutrients,

4. Water.

Seeds need to be dispersed away from the parent plant in order to reduce competition for:

1. Wind

2. Animals

3. Water

4. Mechanical

Seeds can be dispersed by:

Investigate and describe the structure of a non-endospermic seed in terms of the embryo (radicle, plumule and cotyledons) and testa, protected by the fruit

Structure of seed

Radicle

This is the first part to grow out of the seed as it needs to absorb more water

Enzymes

are used in seed germination

break starch down into maltose and then glucose. The glucose is used in respiration to provide energy for growth

Germination

- is the process by which a plant grows from a seed into a seedling.

- All seeds need water, oxygen and optimal temperature to germinate.

- During germination, ROOT is the first to appear from seed

1. Stem grows underground;

2. Sucrose transported to stem from leaves;

3. Sucrose converted to starch;

4. Stem swells and form tuber.

Tuber formation in potatoes

RUNNERS

At certain places where the _________ touches the ground it produces new roots and a new shoot

ex. Strawberry