4.8 Sexual Reproduction System Of Flowering

Plants

Learning Outcomes:Identify the different parts of a flower

Identify the male and female reproductive parts of a flower

Identify the male and female gametes

Describe the functions of the male and female reproductive parts of a flower in sexual reproduction.

Structure of A flower

The flower is the reproductive organ of flowering plants.

The function of the flower is to make gametes and to ensure that fertilisation will take place.

Parts of flowersepals

petals

stamen

pistil

receptacle

pedicel ( flower stalk)

(Pedicel)Receptacle

Pedicel - it also known as the flower stalk.

Receptacle - the enlarged end of the flower stalk.

Sepals - modified leaves that surround the leaves

Petals - modified leaves that usually brightly colored and sometimes scented.

Stamen - male part of the flower. It is made up of anther and filament

Pistil- female part of the flower. It is made up of stigma, style and ovary.

Part Function

SepalsSurround the leaves and protect the parts of the

flower that are still in the bud stage

PetalsUsually brightly coloured and scented to attract

insects. Protect stamen and pistil

AntherProduces pollen grains which carry the male

gametes

FilamentSupport the anther so that the pollen grains can

be dispersed

Stigma Receives pollen grains

StyleSupports the stigma

OvaryProduces the ovules which contain the female

gametes

FEMALEMALE

ovule

Male & Female Parts

Unisexual Flowers

Male

Female

Female male

Unisexual Flower

Unisexual flowers contain either the stamens (male flowers) or the pistils (female flowers)

Examples of plants with unisexual flowers are papaya , oil palm trees and maize plant.

Bisexual Flower

Bisexual Flower

most flowering plants have bisexual flowers which contain both the stamen and the pistils.

Examples of plants : hibiscus, morning glory, flame of the forest

Pollen Grain

Pollen Grain

REVIEW QUESTIONS1. State the functions of the following

parts of the flower: petal, stigma, filament

2. In which part(s) of the flower are the male and female gametes found?

3. What is the difference between unisexual and bisexual flowers?

http://www.youtube.com/watch?v=CXbhdBzx1Ag&feature=related

http://www.youtube.com/watch?v=HQwGEaPJNyM&feature=related

http://www.youtube.com/watch?v=rDN0yAFcQok&feature=related

http://www.youtube.com/watch?v=8zz_B2cYfEk&feature=related