Plant reproduction facts for kids
Plant reproduction is how plants make new plants. They can do this in two main ways: sexual reproduction or asexual reproduction.
Sexual reproduction involves two "parent" plants. They combine special cells called gametes. This creates new plants that are a mix of both parents. So, the offspring are genetically different.
Asexual reproduction means a plant makes new plants all by itself. No special cells from another plant are needed. The new plants are exact copies, or clones, of the parent plant. They are genetically identical, unless small changes called mutations happen.
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How Plants Reproduce Without Seeds
Asexual reproduction does not use male and female cells (gametes) joining together. This type of reproduction can happen in several ways. These include budding, breaking into pieces, spore formation, and vegetative propagation.
When a plant reproduces asexually, the new plant comes from only one parent. This means the new plant gets all its features from that single parent.
Special Plant Parts for Asexual Reproduction
Plants use many different parts to reproduce without seeds.
A rhizome is a special stem that grows underground. It helps the plant spread. New plants can grow from the tips of the rhizome. Examples include polypody ferns, iris, and couch grass.
Some plants have stems that grow along the ground. These are called runners or stolons. They are important for asexual reproduction in plants like strawberry plants, many grasses, and some ferns.
New buds can also grow from roots near the ground. These are called Adventitious buds. They can also grow from damaged stems or old roots. These buds then grow into new stems and leaves above ground. A type of budding called suckering happens when new shoots grow from an existing root system. Plants like elm trees and many rose family members, such as Rosa and Rubus (like blackberries), often produce suckers.
Plants with bulbs, like onions (Allium cepa), hyacinths, and tulips, reproduce by dividing their underground bulbs into more bulbs. Other plants, such as potatoes (Solanum tuberosum) and dahlias, grow new plants from underground tubers. Gladioli and crocuses use similar parts called corms to reproduce.
Gemmae are tiny groups of cells or single cells. They break off from a plant to form new, identical plants. These are common in Liverworts and mosses. They are also found in some Club mosses and plants like Drosera (sundews).
How People Use Asexual Reproduction
While seeds are the most common way people grow plants, many asexual methods are also used. These methods often improve on how plants naturally reproduce.
Some common methods include:
- Cuttings: Taking a piece of a plant and growing roots from it.
- Grafting: Joining a part of one plant onto another plant.
- Budding: Similar to grafting, but using a single bud.
- Layering: Encouraging a stem to root while still attached to the parent plant.
- Division: Splitting a plant into smaller pieces.
These asexual methods are often used to grow specific types of plants called cultivars. These cultivars have special features that might not be passed on through seeds. For example, Fruit tree propagation often uses budding or grafting. This helps grow specific fruit varieties onto strong rootstocks.
When you take a cutting, you cut a branch from a parent plant. You then help it grow roots, sometimes with special powders or liquids that contain hormones. Once the cutting has roots and new leaves, it becomes a new, independent plant. It is an exact genetic copy of the parent.
For example, you can take cuttings from blackberries or African violets to grow new plants. Grafting is a related method where a stem or bud is joined to a different stem. Plant nurseries might sell trees with grafted stems that can grow several types of fruit, like different kinds of apples. Grafting is also used to make plants smaller or protect them from root diseases.
Plants grown asexually are clones. This makes them very useful for plant research. If you grow a clone in different conditions, any differences you see in its growth must be due to the environment, not different genes.
How Plants Reproduce Sexually
In plants, sexual reproduction means special cells (gametes) from two parent plants join together. This creates new plants that are genetically different from both parents. Flowering plants, which are the most common type of plant, can reproduce both sexually and asexually. Bryophytes, like liverworts and mosses, also reproduce both ways. Ferns usually reproduce sexually, but some can also reproduce asexually.
Flowering Plant Reproduction
Flowering plants are the most common plants that reproduce sexually. They have special parts called flowers for reproduction.
Flowers contain male parts called stamens. Stamens make pollen. Pollen grains hold the male gametes. Flowers also have female parts called pistils or carpels. These include the stigma, style, and ovary. The ovary contains tiny structures called ovules, which hold the female gametes.
The Process of Sexual Reproduction
- Pollination
Pollination is when pollen moves from the anther (part of the stamen) to the stigma (part of the pistil). This can happen in many ways. Wind, water, insects, birds, or other animals can carry the pollen. Pollen must reach the stigma for reproduction to begin.
- Fertilization
Once pollen lands on the stigma, it starts to grow a tube called a pollen tube. This tube grows down to the ovary. The male gametes travel through this tube to reach the ovule. Fertilization happens when the male gametes join with the female gametes inside the ovule. This creates a new cell called a zygote.
- Seed Development
After fertilization, the zygote grows into an embryo inside the ovule. The ovule then becomes a seed. A seed contains the embryo and a protective outer layer called a seed coat. The seed then leaves the parent plant. If conditions are right, it can sprout and grow into a new plant.
How Plants Spread and Care for Offspring
One result of plant reproduction is the creation of seeds, spores, gemmae, and other parts. These allow plants to move to new places or new environments.
Plants don't have brains or feelings like animals. But scientists can see how they help their "children" grow and survive. All living things have ways to help their young survive.
For example, the Mammillaria hernandezii cactus, found in Mexico, shows a type of offspring care. This small cactus stores some of its seeds inside its stem. It releases the rest to grow. This can be helpful for many reasons. By keeping some seeds, the cactus protects them from insects, animals, or mold.
A study found that if there is enough water around, M. Hernandezii releases more seeds. This gives the seeds a better chance to grow. The plant can sense the water in its surroundings. It then acts to give its seeds the best chance in a good environment. This clever strategy helps more seeds sprout and grow.
Plants and mammals have some similar ways of reproducing. However, one difference is that in tough environments, mammals often have fewer, larger offspring. Plants, on the other hand, tend to produce more seeds when conditions are harsh.
See also
In Spanish: Reproducción vegetal para niños
