Life of a flowering plant begins with a seed. Seeds can differ in a form, the sizes, weight and coloring, however the principles of the structure of all seeds are identical. Nutrients are necessary for development of any plant.
Instruction
1. The seed consists of a germ, a peel and a reserve of nutrients. A rudiment of future plant is the germ. In it distinguish a germinal back, a small stalk, a budlet and cotyledons. The reserve of nutrients necessary for development of a germ is in endosperm – the special reserving fabric in a seed.
2. Plants can be bichromatic and monocotyledonous. Germs of the first have two cotyledons, the second – one. The volume ratio of a germ and endosperm can also differ: some plants (ash-trees, wheat, onions) the germ the small, and all volume of a seed is occupied by the reserving fabric whereas at others, on the contrary, in process of maturing and growth the germ forces out endosperms (an apple-tree and almonds). At a number of plants (haricot, pumpkin, the strelolist, a chastukha) the seed can consist only of a germ and a seed peel, and the reserve of nutrients at them is concentrated in cotyledons and other cages of a germ.
3. So, the seed is a rudiment of future plant and "reserve" of nutrients for its future growth. When it is based, processes of activity in it proceed sluggishly and imperceptibly, but once it gets on favorable Wednesday, these processes become more active. At this time the seed sprouts.
4. Rise to a new plant is given only by seeds with a live germ. For a number of reasons the germ can die. Make a seed not viable diseases, wreckers, inadequate storage, etc. can. Sometimes germs can die from too long storage of seeds. At water ingress in a seed all seeds bulk up, but sprout from them only viable, and not viable rot.
5. For germination of seeds the conditions favoring to it, main of which – availability of water, air and heat are necessary. The germ consumes nutrients only in the form of solution, however different seeds require a different amount of water. The same can be told concerning heat and air.
6. The first of a seed of a plant sprouts a back: having broken off a peel and having come to light a seed, it quickly grows and becomes stronger in the soil, absorbing from it water and mineral substances. Further the small stalk lifting a budlet and cotyledons (future leaves) over the surface of the soil begins to grow. Remain with a part of plants of a cotyledon in the soil, and elevated escape develops from a budlet.
7. The organic matter reserved in a seed is used for food of future plant until the sprout reaches the surface of the soil. But if they are spent before photosynthesis process begins, the sprout can die.