Structure of a Flower
Sexual Reproduction in Flowering Plants
Sexual reproduction is when an offspring is formed starting with the fusion of male and female gametes. Plants are capable of sexual reproduction, too!
Flowers contain the male and female reproductive organs in a plant as discussed below. Some plants only have flowers with male reproductive organs, some have only female reproductive organs, while others have both male and female reproductive organs.
Unisexual plants – plants that only contain either the male or female reproductive organ are known as dioecious plants.
Bisexual plants – plants that contain both male and female reproductive organs are known as hermaphrodites.
Watch the video for a full summary of the post
Male Reproductive Organ in the Flower
Sperms are the male gametes in humans. In flowers, the male gamete is in the pollen grain. The male reproductive organ of the flower is the stamen, which consists of the anther and the filament.
- Anther – This is where four pollen sacs are found. There are hundreds of pollen grains in each pollen sac.
- Filament – It holds the anther up so that when the pollen grains are released from the anther, it can be picked up by pollinating agents.
Together, the anther and the filament form the stamen.
Female Reproductive Organ in the Flower
The ovum (egg cell) is the name given to the female gamete in both humans and plants. The female reproductive organ of the flower is the carpel which consists of the stigma, style and ovary.
- Stigma – This sticky top part of the carpel acts as the site for pollen grain to land.
- Style – It holds the stigma up and increases the chances of pollen grains landing on the stigma.
- Ovary – The bulging part at the bottom of the carpel is the ovary. In it are the ovules. An ovary can contain one or more ovules. This is where the female gamete (ovum or egg cell) can be found.
Together, the stigma, style and ovary form the carpel.
Other Parts of the Flower
There are parts of the flower which do not make up the sexual reproductive organs in the flower. They are the petal, sepal and peduncle.
Sepal – The role of the sepal is to protect the flower bud before it blooms. It is usually green in colour and looks like a leaf at the base of the flower.
Petal – Flower petals are very commonly used as a decorative item since they are colourful and beautiful to look at. These properties of the petal give it the role of attracting pollinating agents such as insects and birds.
Peduncle – This is the part of the flower stalk that attaches to the flower.