Life cycle of flowering plants

Presentation for teaching angiosperm life cycles to middle schoolers

1. The Life Cycle Of Flowering Plants

2. Flowering Plants (Angiosperms) Flowering plants, also called angiosperms , are a category of plants that produce or bear flowers. Examples are beans, mango, most grasses, maize, guava and hibiscus. Angiosperms, together with gymnosperms , are seed-bearing plants. Non-flowering plants are the other category of plants which do no produce or bear flowers. Examples are cassava, potatoes, ferns, moss, etc. beans mango grass maize hibiscus cassava fern moss

3. Stages in the Life Cycle of Flowering Plants

4. Flowering This is the stage where a flower develops from a bud. In the bud stage, the sepals cover the petals and the flower is closed and only opens up when it is fully developed.

5. Flowers A flower is the organ of a plant that is responsible for sexual reproduction. Petals, which form the corolla , are brightly colored, and sweet-smelling to attract insects, birds, and other agents of pollination Sepals, which form the calyx , protect the rest of the flower while it is still developing. Anther Filament Stamen , the male reproductive part of a flower Style Stigma Ovary Ovules Carpel , the female reproductive part of a flower Stalk

6. Pollination Self-pollination: this occurs when pollen grains are transferred from the anther of a flower to the stigma of the same flower or another flower of the same plant. It is the transfer of pollen from the anther to the stigma of a flower. Pollen grains are the male sex cells (gametes) in the flower, and are produced in the stamen. The main agents of pollination are wind and small animals and insects, such as bees, butterflies, humming birds, etc. Cross-pollination: this occurs when pollen grains are transferred from the anther of a flower to the stigma of a flower on another plant of the same kind.

7. Fertilization This refers to the fusion of the male and female gamete of a plant to form a zygote . The male gametes of a flower are the pollen grains , and the female gametes are the ovules . When pollen lands on the stigma of a flower, it grows a pollen tube down the style and into the ovary in order to reach the ovules. stigma Pollen tube anther ovary ovules

8. Fertilization and Fruit-Bearing After fertilization, the zygote(s) (ovules + pollen) develops into the seed(s) and the ovary develops into a fruit (pericarp). The fruit has three main layers which are epicarp/exocarp , mesocarp and endocarp moving from the surface towards the interior. The seed is covered with a hard coat called a testa , and has cotyledon and/or endosperm to store food for germination.

9. Dispersal of Fruits and Seeds This is the process by which fruits and seeds are carried/scattered away from the parent plant. Mechanisms of seed dispersal: Animal agents such as humans, birds and monkeys. Examples of fruits that are dispersed this way include mango, berries, tomatoes, etc. Wind, e.g. for Tridax , dandelions, cotton, etc. Water, e.g. for coconuts, red mangrove, etc. Explosive mechanism, e.g. for okra ( okro ), Pride of Barbados, soybean, etc.

10. Seed Germination Germination is the development a new plant from a seed. The roots begin developing before the shoot system.

11. Factors Necessary For Germination External Water Air Suitable temperature Internal Viability of seed Enzymes