Lesson 3A – Flowers, Fruits and Seeds INTRODUCTION Science 3001 Science II: Earth & Life Sciences I Mr. Kishore Lal Living Things Lesson 3A – Flowers, Fruits and Seeds

Flowers, Fruits and Seeds Reproduction in plants Life cannot exist without plants. There are three methods of reproduction in plants: From seeds. From spores. Vegetative propagation (from body parts)

Flowers, Fruits and Seeds Parts of the Flower Flowers are important in producing seeds. While flowers can be different, there are some parts that are found in many flowers. Some flowers can be small and dull looking like tiny leaves e.g.plum, or pommecythe, while others can be quite conspicuous as single flower or bunches of flowers.

Flowers, Fruits and Seeds Parts of the Flower. Stamen - the male part. Anther - produces male gametes (pollen). Filament - supports anther. Pistil - the female part. Stigma - sticky portion at the top of the style where pollen grains usually land. Style - the narrow elongated part of the pistil between the ovary and the stigma. The pollen tube grows into the style to reach the ovule for fertilization. Ovary - contains ovules After fertilization, the ovary may become the fruit. Ovule - the female gamete (egg)which become seeds.

Flowers, Fruits and Seeds Parts of the Flower. Petal (corolla) - often conspicuously colored and may attract insects. Pedicel - the stalk of a flower. Sepal (calyx) - external covering of flower bud. (often green and leaf-like). Stalk - supports the flower Receptacle - the part of a flower stalk where the other parts of the flower are attached. Meiosis is the process of cell division that produces gametes (sex cells) in the ovary and anther

Flowers, Fruits and Seeds Seed and Fruit Formation. When the pollen lands on the sticky stigma it begins to grow a pollen tube towards the ovary. This allows its nucleus to fertilize a single ovule. The outer cell layers of ovule form seed coat. Seed coat forms slows down metabolic activities and protects young plant when it’s the most vulnerable. Seed has stored food for germination to postpone development until favorable conditions. The fruit develops from the ovary. Germination can’t start until water/oxygen reaches embryo and other appropriate conditions (e.g. heat, available nutrients, chemicals, pass through animal intestines, etc).

Flowers, Fruits and Seeds Main Parts of a Seed Testa – (Seed Coat) i.e. the protective covering which protects the baby plant inside the seed. It has a tiny hole through which the seed gets water. Cotyledons (Seed Leaves) - They contain food for a growing baby plant. Embryo – the parts that will become the shoot and root Plumule – this becomes the shoot Radicle – this becomes the root

Flowers, Fruits and Seeds Germination is the development of a seed into a seedling (baby plant). The seed needs oxygen, water and warmth (from sunlight) for germination. Germination - From the emergence of the plumule and radicle to the first true leaves.

Flowers, Fruits and Seeds Stages of growth Seed absorbs water from the soil. Seed coat becomes soft and it breaks up and the baby root (radicle) emerges followed by the baby shoot (plumule). Root grows down into the soil. Baby shoot develops and grows towards the sunlight. Tiny leaves appear on the shoot. As the leaves grow, they start making their own food (photosynthesis). The new plant produces flowers which grow into fruits. Fruits contain seeds. Given suitable condition of air, water and warmth, these seeds germinate and grow into new plants. In this way the cycle of reproduction in plants continues.

Flowers, Fruits and Seeds Dispersal of seeds Dispersal helps the seeds to reach the suitable place where they get enough air, water and warmth needed for their germination. It prevents the competition of seeds growing near the mother plant.

Flowers, Fruits and Seeds Dispersal of seeds Seeds need to be scattered away from the mother plant. Dispersal of seeds is accomplished by agents like animals, birds, human beings air Water explosion.

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