Sexual Reproduction in Plants

Sexual Reproduction – Plants! Cycle that allows plants to reproduce sexually is the same as in animals. Cycle that allows plants to reproduce sexually is the same as in animals. Seeds are the products of sexual reproduction in most plants. Seeds are the products of sexual reproduction in most plants. Seed – contains an embryo, a food supply, and a seed coat, which protects the seed from drying out. Seed – contains an embryo, a food supply, and a seed coat, which protects the seed from drying out.

Plants! Seed-producing plants can be divided into 2 groups: Seed-producing plants can be divided into 2 groups: 1. Angiosperms – enclosed seed 2. Gymnosperms – naked seed

Angiosperms Flowering plants Flowering plants Seeds form inside the flower Seeds form inside the flower When mature, the seeds are enclosed in a shell, such as a pod or a case. When mature, the seeds are enclosed in a shell, such as a pod or a case. Some have showy flowers – such as a lily. Some have showy flowers – such as a lily. Others produce very tiny flowers – such as grasses. Others produce very tiny flowers – such as grasses.

Angiosperms Flowers contain the reproductive organs. Flowers contain the reproductive organs. The female reproductive organ is called the pistil. The female reproductive organ is called the pistil. The male reproductive organ is called the stamen. The male reproductive organ is called the stamen.

Pistil Includes: Includes: Stigma – sticky lip of the pistil that captures pollen grains Stigma – sticky lip of the pistil that captures pollen grains Style – stalk that supports the stigma Style – stalk that supports the stigma Ovary – swollen base containing ovules Ovary – swollen base containing ovules Ovules – sacs containing female gametes Ovules – sacs containing female gametes

Stamen Includes: Includes: Anther – where the pollen is produced and stored Anther – where the pollen is produced and stored Pollen Grains – cases containing male gametes Pollen Grains – cases containing male gametes Filament – stalk the supports the anther Filament – stalk the supports the anther

Pollination Pollination –seeds begin to develop when the pollen grains reach the stigma of the pistil. Pollination –seeds begin to develop when the pollen grains reach the stigma of the pistil. Self- Pollination - both male and female gametes come from the same flower Self- Pollination - both male and female gametes come from the same flower Cross – Pollination - brings together gametes from different parent plants. Cross – Pollination - brings together gametes from different parent plants. The 2 most common helpers for cross- pollination are the wind and insects The 2 most common helpers for cross- pollination are the wind and insects

Pollination Pollination is not enough to ensure fertilization. Pollination is not enough to ensure fertilization. The pollen grains must grow a pollen tube – which will grow and reach the ovule inside the pistil. The pollen grains must grow a pollen tube – which will grow and reach the ovule inside the pistil.

Seed Matured When the sperm reaches the egg it creates a zygote. When the sperm reaches the egg it creates a zygote. The zygote will undergo Mitosis and create a many celled embryo with a miniature leaf, root and stem, and a case that surrounds it and stores food. The zygote will undergo Mitosis and create a many celled embryo with a miniature leaf, root and stem, and a case that surrounds it and stores food. As the seed matures it forms a fruit – such as a pod or a case, around the seed. As the seed matures it forms a fruit – such as a pod or a case, around the seed.

Seed Dispersal This increases the likelihood that offspring will survive – as they will not be competing with the parent for water, soil, and sunlight. This increases the likelihood that offspring will survive – as they will not be competing with the parent for water, soil, and sunlight. Animals, wind, and running water help with the dispersal of seeds. Animals, wind, and running water help with the dispersal of seeds

Gymnosperms Gymnosperms produce their seeds inside cones – cones are the reproductive organs. Gymnosperms produce their seeds inside cones – cones are the reproductive organs. Some species will produce female and male cones on separate tress – while others produce both cones on the same tree. Some species will produce female and male cones on separate tress – while others produce both cones on the same tree

Check your Understanding! Answer the following questions: Page 59 1, 4 Page 71 2a c, 3