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A seed is an undeveloped plant with stored food, sealed in a protective covering. It may sprout into a new plant in a process called germination.
To germinate, a seed must move away from where it was made. It will sprout with warmth and water. First, the seed takes in water. As it swells, the seed coat splits open. A root grows out of the seed. Then a tiny stem appears. If conditions are right, the seedling will mature into an adult plant.
In most plants, seeds are made in flowers. The seed forms when a male sex cell joins with a female sex cell. Male sex cells are made in a flower part called the anther, and are stored in a kind of powder called pollen. Female sex cells, the eggs, are kept in a flower part called the pistil.
The transfer of a pollen grain to the pistil is called pollination. Pollination can take place within the anther and pistil of one flower, or between different flowers. Plants rely on animals, wind, or water to help with pollination.
Insects or other animals are attracted to the bright colors or sweet smells of some flowers. They feed on pollen or a sugary food called nectar that flowers make. As they move from flower to flower, they may transfer the sticky pollen.
After pollination, the next step in the formation of a seed is the joining of a male sex cell and a female sex cell. This process is called fertilization. First, a pollen tube grows down the pistil into the ovary. The ovary holds egg cells. The male sex cell travels from the pollen, down the pollen tube, and combines with the egg.
A seed develops from the fertilized egg. The ovary turns into a fruit around the seed.
A seed usually grows best away from the parent plant. Seeds are carried away, or dispersed, in different ways. Dandelion seeds may travel long distances in the wind. Fleshy fruit may be eaten by animals. The seeds may fall to the ground as animals eat the fruit. Or seeds may pass through the animals’ droppings. Some seeds stick to an animal’s fur, then fall off in a new place.
Most plants make a huge number of seeds. That way, at least some of the seeds should sprout and mature into new plants.
Mosses, ferns, and other plants grow not from seeds, but from spores. A spore can grow into a new plant, but is not produced from sex cells. It is made from just one parent plant.
A moss plant has two separate stages to its life cycle. First, it produces spores. The spores grow into plants that have male branches and female branches. In the second stage, one sex cell from the male branch combines with one sex cell from the female branch. This forms a fertilized egg, which grows into a thin stalk with a spore case on top.
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[two_on_two]
A seed is an undeveloped plant with stored food sealed in a protective covering. The seed coat is the protective covering. Germination is the process of a seed sprouting into a new plant. A seedling is a young plant that grows and develops from a seed. A seed grows when it has water, light, and warm temperatures.
Seeds are formed when the male sex cells join female sex cells. Male sex cells are found in the pollen. Pollen is produced by the anther. Female sex cells are found in the pistil. Pollination is when the pollen grain is transferred from an anther to a pistil.
Fertilization is the joining of the female sex cell and male sex cell into one cell. This is called a fertilized egg. The ovary contains the fertilized egg and grows to form a protective fruit. An embryo is formed from the seeds of a root, stem, and leaves. Inside a seed are an embryo and a food source.
Seeds are carried away by the wind, moving water, exploding fruits, and by sticking to animal fur and other body parts. It also passes out of animals after being eaten. The life cycle of flowering plants consists of six steps. Animals help flowering plants in these ways. Bees pollinate flowers. Animals eat the fruit and disperse the seeds in their droppings.
A spore is a seedless plant. Spores live in dry places and can withstand high and low temperatures. Plants such as mosses and ferns use spores. They have no sex cells and can grow into new plants.
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