Reproduce using flowers, pollination, seeds, and fruits
Reproduce using cones, spores, or other methods
Examples
Rose, hibiscus, sunflower, mango tree, pea plant, tomato plant
Fern, moss, pine tree, cycad, horsetail
Plant life cycles
Plant Life Cycle Steps:
Seed stage
A plant life cycle begins with a seed. The seed contains a tiny young plant called an embryo. It also has stored food that helps the embryo start growing.
Germination
When the seed gets enough water, air, and a suitable temperature, it begins to germinate. The seed coat becomes soft and breaks open.
Root grows first
A small root grows downward into the soil. The root holds the plant in place and absorbs water and minerals from the soil.
Shoot grows upward
A shoot grows upward towards the light. The shoot later develops into the stem and leaves.
Young plant grows
The plant grows taller and stronger. Leaves make food for the plant using sunlight, water and carbon dioxide. This process is called photosynthesis.
Flowering stage
When the plant becomes mature, it produces flowers. Flowers are important because they help the plant reproduce.
Pollination
Pollen moves from the anther of one flower to the stigma of the same or another flower. This may happen with the help of insects, wind or other animals.
Fruit and seed formation
After pollination, the flower begins to change. The ovary develops into a fruit, and seeds form inside the fruit.
Seed dispersal
When the fruit is ripe, the seeds are released. Seeds may be carried away by wind, water, animals or by the fruit bursting open.
Cycle begins again
If the seeds land in a suitable place with enough water, air and warmth, they germinate and grow into new plants. This is how the plant life cycle continues.
Flower-Parts and Functions
Parts of a flower:
Functions of the parts of a flower: Male part of the flower: Stamen
The male reproductive part of a flower is called the stamen. It is made up of:
PartFunction
Anther
Produces pollen grains. Pollen contains the male reproductive cells.
Filament
A thin stalk that holds the anther up so that pollen can be easily released or picked up by insects/wind.
So:
Stamen = Anther + Filament
The anther is the main pollen-producing part, while the filament supports it.
Female part of the flower: Pistil / Carpel
The female reproductive part of the flower is called the pistil or carpel.
It is made up of: PartFunction
Stigma Sticky top part that receives pollen during pollination.
Style
A tube-like structure that connects the stigma to the ovary. It allows the pollen tube to grow down towards the ovary.
Ovary
Contains ovules. After
fertilisation
, the ovary develops into a fruit.
Ovules
Found inside the ovary. After
fertilisation
, ovules develop into seeds.
So:
Pistil / Carpel = Stigma + Style + Ovary
The stigma receives pollen, the style connects the stigma to the ovary, and the ovary contains ovules that can become seeds.
Other parts shown in the diagram PartFunction
Petal
Usually large and colourful. Petals attract insects and other pollinators to the flower.
Sepal
Protects the flower when it is still a bud. Sepals are usually green and found at the base of the flower.
Receptacle
The swollen part at the base of the flower where all flower parts are attached.
Pedicel
The stalk of the flower. It holds the flower and connects it to the plant.
Summary :
The male part of the flower is the stamen, made of the anther and filament. The anther makes pollen.
The female part of the flower is the pistil/carpel, made of the stigma, style, and ovary.
The stigma receives pollen, the style connects to the ovary, and the ovary contains ovules that become seeds after
Sub-Topics: Pollination and fruit and seed production
Pollination
Definition: Pollination is the transfer of pollen grains from the anther of a flower to the stigma of a flower of the same kind.
In animal pollination, animals help to carry pollen from one flower to another. These animals are called pollinators.
Animals usually visit flowers to collect or drink nectar. Nectar is a sweet liquid made by flowers. While the animal is feeding, pollen grains from the anthers may stick to its body. When the animal visits another flower of the same kind, some of the pollen may rub off onto the sticky stigma. This helps pollination to take place.
Examples of animal pollinators
Pollination can be carried out by many small animals such
as:bees
, butterflies, moths, birds, bats and some other insects.
Some larger animals can also help in pollination. These include some birds and mammals such as hummingbirds, sunbirds, honeyeaters, lorikeets, flowerpeckers, sugarbirds, bats, honey possums, sugar gliders, lemurs and some monkeys.
Process of Pollination:
Example 1: Pollination by a bee
A bee visits Flower A to drink nectar. As the bee moves inside the flower, its body rubs against the anthers. The anthers produce pollen. Some pollen grains stick to the bee’s body, legs and hairs.
The bee then flies to Flower B, which is another flower of the same kind. As the bee feeds from Flower B, some pollen grains from its body rub off onto the sticky stigma of Flower B.
This transfer of pollen from the anther of Flower A to the stigma of Flower B is called pollination.
After pollination, the flower can begin the process of making seeds.
Example 2: Pollination by a bird
Some birds drink nectar from flowers. These birds often have long or curved beaks that help them reach nectar deep inside flowers.
A hummingbird is a famous nectar-drinking bird. It can hover in front of a flower and use its long beak to drink nectar. While feeding, pollen may stick to its beak, head or feathers. When the hummingbird visits another flower of the same kind, the pollen may rub off onto the stigma. This helps pollination.
Other nectar-feeding birds include:
Sunbirds — common in Asia and Africa, including India. They are small birds with curved beaks and often visit flowers such as hibiscus.
Honeyeaters — found mainly in Australia and nearby regions. They use their beaks and tongues to feed on nectar.
Lorikeets — colourful parrots that feed on nectar, pollen and fruits.
Flowerpeckers — tiny birds found in parts of Asia. Some feed on nectar, berries and small fruits.
Sugarbirds — found in southern Africa. They feed on nectar from flowers such as proteas.
When these birds drink nectar, pollen may stick to their beak, head or feathers. When they visit another flower, the pollen can rub off onto the stigma and help in pollination.
Example 3: Pollination by a monkey
Some monkeys and monkey-like primates may drink nectar or feed on flowers. When they push their face into a large flower to lick nectar or eat flower parts, pollen can stick to their face, hands or fur.
For example, some tamarins have been observed feeding on nectar. When a tamarin visits one flower, pollen may stick to its face or fur. If it then visits another flower of the same kind, some pollen may be transferred to the stigma.
Some other primates, such as howler monkeys, langurs and macaques, may feed on flowers. They may not always be as important as bees or birds in pollination, but they can sometimes carry pollen on their face, hands or fur.
Lemurs are not monkeys, but they are primates. Some lemurs are well-known for helping in pollination when they feed on nectar from large flowers.
Animal-pollinated flowers features
Flowers pollinated by animals often have special features to attract pollinators. They are as follows:
large petals
colourful or bright petals
scented
nectar [nectaries]
anthers / stigmas, inside the flower
sticky and spiky pollen grains ;
make less pollen as compared to the wind pollinated flowers
Key idea
Animals do not usually visit flowers to pollinate them. They visit flowers to get food, such as nectar or pollen. Pollination happens because pollen sticks to the animal’s body and is carried to another flower of the same kind.
Pollination by animals helps flowering plants produce seeds.
Pollination by wind
In wind pollination, the pollen blows in the wind from the anthers to the stigmas of other flowers. Grass, rice and corn flowers are wind pollinated.
Features of Wind-Pollinated Flowers
Wind-pollinated flowers are adapted to transfer pollen from one flower to another using wind instead of insects or animals. These flowers do not need to attract pollinators, so their structure is different from insect-pollinated flowers.
1. Flowers are small or absent
Wind-pollinated flowers are usually very small. In some plants, petals may be absent or hardly visible.
Since these flowers do not need to attract insects, they do not need large, colourful petals.
2. Flowers are dull in colour
If petals are present, they are usually dull, greenish, brownish or pale.
Bright colours are not needed because wind-pollinated flowers do not depend on insects, birds or other animals for pollination.
3. No scent
Wind-pollinated flowers usually have no scent.
Insect-pollinated flowers often produce scent to attract insects, but wind-pollinated flowers do not need this feature.
4. No nectar
Wind-pollinated flowers usually do not produce nectar.
Nectar is used to attract pollinators such as bees and butterflies. Since wind carries the pollen, nectar is not needed.
5. Large amounts of pollen are produced
Wind pollination is a less certain method because the wind may blow pollen in any direction.
To increase the chance of some pollen reaching the stigma of another flower, wind-pollinated plants produce large amounts of pollen.
6. Pollen grains are small and light
The pollen grains are usually small and light.
This helps them to be easily carried by the wind over a distance.
7. Pollen grains are smooth
The pollen grains are usually smooth and not sticky.
Smooth pollen grains can float and move more easily through the air.
8. Anthers are exposed
The anthers are usually found outside the flower or hanging loosely.
This allows the wind to easily blow pollen away from the anthers.
9. Pendulous anthers
Many wind-pollinated flowers have pendulous anthers, meaning the anthers hang down and swing in the wind.
When the wind blows, the anthers shake and release pollen into the air.
10. Stigmas are large and feathery
The stigma is often large, branched and feathery.
This increases the surface area of the stigma, helping it catch pollen grains floating in the air.
11. Stigmas are exposed
The stigma is usually positioned outside the flower or in a place where wind-blown pollen can easily reach it.
This improves the chance of catching pollen carried by the wind.
12. Flowers may hang in clusters
Some wind-pollinated flowers hang in groups or clusters, such as in grasses or catkins.
This helps pollen to be released easily into the air and increases the chance of successful pollination.
Summary
Wind-pollinated flowers usually have small, dull flowers, no scent, no nectar, exposed pendulous anthers, feathery stigmas, and they produce large amounts of small, light, smooth pollen.
Why must flowers be pollinated?
Plants Reproduce by Making Seeds
Plants reproduce by making seeds.
Seeds are formed when the pollen and egg join together. This process is called
fertilisation
.
Pollination
Pollination is the transfer of pollen from the male anther to the female stigma of a flower.
The anther is the male part of the flower that produces pollen.
The stigma is the female part of the flower where pollen lands.
Pollination is important because it allows
fertilisation
to happen.
Fertilisation
Fertilisation
happens when the pollen and egg join together.
Fertilisation
takes place inside the flower’s ovary.
After
fertilisation
, seeds begin to form.
Fertilisation
only happens if the pollen and the egg come from the same kind of flower.
For example, pollen from one type of flower can
fertilise
the egg of the same type of flower, but not a different kind of flower.
What Happens After
Fertilisation
?
After the egg is
fertilised
, some parts of the flower are no longer needed.
The petals die.
The stamens die.
The ovary grows bigger and becomes the fruit.
The seeds form inside the fruit.
Pollination
Fertilisation
Pollination happens first.
Fertilisation
happens after pollination.
It is the transfer of pollen from the anther to the stigma.
It is the joining of the male part from pollen with the egg.
Soft, juicy tasty fruits
