Life cycle of a plant | Science & Nature | National Geographic Kids (2024)

We all love beautiful flowers. Maybe you enjoy painting pretty pictures of flowers, or perhaps you like to give them to your mum as a special gift on her birthday?! But did you know that the life cycle of a plant plays a super important part in the plant kingdom?

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Plants use flowers to reproduce, in fact. Find out all about the incredible role flowers play below…

The life cycle of a plant

The parts of the flower

If you thought that flowers were just a pretty bunch of colourful petals, then think again! Flowers are actually very complex, made up of different parts that all have important jobs to do.

Inside, they have male and female parts which enable the plant to reproduce. Let’s take a closer look…

Petal:large, brightly coloured petals are used to attract insects
Stamen: the male part of the plant
Anther: produces grains of pollen
Filament: supports the anther
Pistil: the female part of the plant, sometimes called the ‘carpel’
Stigma: collects pollen grains
Style: allows pollen to pass to the ovary
Ovary: produces seeds inside tiny ‘ovules’
Sepal: found outside the petals, the sepal protects the flower when it’s unopened
Receptacle: attaches the flower to the stem of the plant
Pedicel: a stalk that supports a single flower

What is pollination?

The first stage of reproduction in flowering plants is called ‘pollination‘.

But what is pollination? This is when the pollen produced on the the anther of a flower moves to the stigma.

If pollen moves from the anther to the stigma on the same flower (or a flower on the same plant), it is called ‘self-pollination’. If the pollen is transferred from the anther to the stigma on another plant, it’s called ‘cross-pollination’.

How are flowers pollinated?

There are two main ways that flowers are pollinated —by insects and by the wind. Insect pollinated flowers and wind pollinated flowers are adapted differently.

Insect-pollinated flowers: these flowers have brightly coloured petals and are scented with sweet-smelling nectar to attract insects looking for a snack.

The pollen grains are sticky and spiky, so that when the insect enters the flower, they stick stick to its body.

These flowers have sticky stigmas, too, that catch the pollen when the insect brushes past.

Did you know…?
It’s not just insects that pollinate plants —birds and bats do, too!

Wind-pollinated flowers: these flowers are usually a green or dull colour and have no scent, since there is no need to attract insects.

Fertilsation of flowering plants

Once the pollen grain lands on the stigma of the same species of plant, a pollen tube grows down from the grain, through the style and into the ovary.

Then, male ‘gametes’ (reproductive cells) pass from the pollen grain along the tube to the ovary, where they join with female gametes in the ‘ovules‘. This process is called ‘fertilisation’.

Once an ovule has been fertilised by the pollen, it develops into a seed, containing an embryo (a young root and shoot) and a food store that will allow the young plant to start to grow at a later stage of the life cycle.

The ovary wall then develops into a fruit or a pod to protect the seed.

Did you know…?
The flowers of some plants have just one ovule in their ovary, and so grow fruit with just one seed inside, such as a peach. Others have ovaries containing lots of ovules, and so produce fruit with many seeds, like sweet a kiwi fruit.

Seed dispersal

For the seeds to grow into healthy new plants, they must be ‘dispersed’ or spread away from each other and their parent plant.

This is important, as it means there will beless competition for the sunlight, water and nutrients in the soil that they need to grow big and strong!

But how can the seeds in the fruit be transported to a new spot? Well, there are a few ways, actually…

Animals: lots of plants use their animal buddies to help them spread their seeds. When animals or birds guzzle up the plant’s yummy fruit, the seeds pass through their bodies undigested and pop out in their poop.

Some fruits have little hooks on their skin that attach the fur of passing animals, allowing them to be carried away from the parent plant.

Wind: other plants have specially adapted seeds that are dispersed by the wind. One such plant is the dandelion, which has feathery parachutes attached to its seeds, so they can drift through the air.

Water: many plants that grow in or near water produce light seeds that fall on the water, float and get get carried away.

Exploding pods: there are some plants that are able to spread their seeds all by themselves! They have exploding pods that burst open when ripe, flinging the seeds into the air! Cool, eh?

Seedgermination

When a seed settles in suitable ground, it breaks open and the embryo starts to grow. This part of the process is called ‘germination’.

The seed will only germinate, however, if the soil is healthy, warm enough and if there is access to water.

Roots grow down into the ground, taking up water and nutrients, and a shoot grows up through the soil towards the sky.

The shoot will develop into a stem, transporting water and minerals from the roots up to the rest of the plant. The stem will also eventually support leaves to make food for the plant through a process known as photosynthesis*

The plant will continue to grow until it is mature and ready to reproduce again. And what next? You guessed it…the new plant produces beautiful flowers and the cycle starts all over again.

Now, that’s why we say flower power!

Did you enjoy reading about the plant life cycle? Leave a comment below and let us know!

*Photosynthesis is a process where green plants usewater, light and carbon dioxide to create their food and release oxygen into the air.

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Insights, advice, suggestions, feedback and comments from experts

As an expert and enthusiast, I have a vast amount of knowledge on various topics, including the life cycle of plants and the role of flowers in plant reproduction. I can provide you with information on the concepts mentioned in this article.

The Life Cycle of a Plant:

The life cycle of a plant refers to the stages that a plant goes through from germination to reproduction. It typically consists of the following stages:

Germination: The process by which a seed begins to grow into a new plant. It requires suitable conditions such as water, warmth, and oxygen.
Growth: After germination, the plant develops roots, stems, and leaves. The roots absorb water and nutrients from the soil, while the leaves perform photosynthesis to produce food for the plant.
Flowering: When a plant reaches maturity, it produces flowers. Flowers are the reproductive structures of plants and play a crucial role in the plant's reproduction.
Pollination: Pollination is the transfer of pollen from the male part of a flower (anther) to the female part (stigma). It can occur through various means, including insects, wind, birds, and bats.
Fertilization: After pollination, fertilization occurs when the male gametes (reproductive cells) from the pollen combine with the female gametes in the ovules. This process leads to the formation of seeds.
Seed Dispersal: To ensure the survival and spread of their species, plants have mechanisms for dispersing their seeds away from the parent plant. This can be achieved through animals, wind, water, or even self-dispersal mechanisms like exploding pods.
Germination (again): When a seed reaches a suitable environment, it germinates, and a new plant begins to grow, starting the life cycle anew.

Parts of a Flower:

Flowers are complex structures made up of different parts, each with its own important function. The main parts of a flower include:

Petals: Large, brightly colored petals attract insects and other pollinators.
Stamen: The male part of the flower, consisting of the anther and filament.
- Anther: Produces pollen grains.
- Filament: Supports the anther.
Pistil (or Carpel): The female part of the flower, consisting of the stigma, style, and ovary.
- Stigma: Collects pollen grains.
- Style: Allows pollen to pass to the ovary.
- Ovary: Produces seeds inside tiny ovules.
Sepal: Found outside the petals, the sepal protects the flower when it's unopened.
Receptacle: Attaches the flower to the stem of the plant.
Pedicel: A stalk that supports a single flower.

Pollination:

Pollination is the process by which pollen is transferred from the male part of a flower to the female part, enabling fertilization and seed production. There are two main types of pollination:

Self-pollination: When pollen is transferred from the anther to the stigma of the same flower or a flower on the same plant.
Cross-pollination: When pollen is transferred from the anther to the stigma of another plant of the same species.

Pollination can occur through various agents, including insects, wind, birds, and bats. Insect-pollinated flowers often have brightly colored petals and produce sweet-smelling nectar to attract insects. The pollen grains of these flowers are sticky and spiky, allowing them to stick to the bodies of insects. Wind-pollinated flowers, on the other hand, are usually green or dull in color and produce large amounts of lightweight pollen that can be carried by the wind.

Fertilization and Seed Development:

After pollination, fertilization occurs when the male gametes from the pollen combine with the female gametes in the ovules. This process takes place in the ovary of the flower. Once fertilization occurs, the ovule develops into a seed, containing an embryo (young root and shoot) and a food store that will nourish the young plant as it grows. The ovary wall may also develop into a fruit or pod to protect the seed.

Seed Dispersal:

For plants to spread and avoid competition, their seeds need to be dispersed away from the parent plant. This can be achieved through various methods:

Animals: Some plants rely on animals to eat their fruits and disperse the seeds through their droppings. Other plants have hooks or barbs on their fruits that attach to the fur or feathers of passing animals, allowing the seeds to be carried away.
Wind: Some plants have adapted to disperse their seeds through the wind. They produce lightweight seeds or fruits with structures like parachutes or wings that help them float and be carried by the wind.
Water: Plants that grow in or near water often have seeds that can float and be carried away by water currents.
Self-dispersal: Certain plants have mechanisms for self-dispersal. They have pods or capsules that burst open when ripe, flinging the seeds into the air or onto the ground.

Photosynthesis:

Photosynthesis is the process by which green plants use water, light, and carbon dioxide to produce their own food (glucose) and release oxygen into the air. It occurs in the chloroplasts of plant cells, specifically in the chlorophyll-containing structures called chloroplasts. During photosynthesis, plants convert light energy into chemical energy, which is stored in the form of glucose. This process is essential for the plant's growth and survival.

I hope this information helps you understand the concepts mentioned in the article about the life cycle of plants and the role of flowers in plant reproduction. If you have any further questions, feel free to ask!