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Group 3 Presentation Good morning Mrs Cheong and fellow friends.
Today we are going to present about “How seeds are formed?”
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How seeds are formed? (1) A flower exists to produce seed.
Stamen produces pollen grains that later form the male cells, or sperms. It has stalk, or filament, at the tip of which is the pollen sac, or anther.
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How seeds are formed?(2) Pistils are usually in the centre of the flower, is the female organ. 3 distinct parts: The ovary, which contains 1 or more immature seeds, called ovules; above the ovary, a slender style, or tube; at the tip of the style, the stigma, on which the pollen is deposited.
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How seeds are formed?(3) Stamen and pistil are called essential organs because they are necessary if there is to be seed. 2 other organs ; sepals and petals are not involved in sexual reproduction.
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How seeds are formed?(4) Some flowers do not have sepals and petals. We call them accessory organs. A flower that has all four organs is a complete flower. The sepals are the lowest of the four organs.
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How are seeds formed?(5) They look like leaves and their main function is to protect the bud until it has developed into a flower. The sepals collectively are called the calyx.
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How seeds are formed?(6) Above and inside the calyx are the petals, known collectively as the corolla. In many flowers they are coloured. Petals of many flowers have glands nectaries in which a sweet liquid, called nectar, is secreted.
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How seeds are formed?(7) Colours of the nectar, and the odours of essential oils produced by the petals of many flowers attract insects, hummingbirds, people, and other creatures, which, with wind and gravity. The reproductive organs are formed in separate flowers on the same plant.
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How seeds are formed?(8&9)
Such plants are said to be monoecism. The watermelon, cucumber, and other members of the gourd family are examples. Individual plants of some species have one-sexed flowers that is, flowers on a plant may have only stamens, and the flowers of another plant of the species may have only pistils. Such plants the term dioeciously is applied.
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Thank you for paying attention.
Done by :Amanda, Hao Jie , Jia Yi , Zi Yi.
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