What is the life cycle?

It is defined as the developmental stages that occurred during an organism's lifetime. It is a process where new lives come into existence. They grow and change themselves; as they get older, they produce their own offspring. The life cycle is repeated each generation.

Animal life cycles

 Different animals can have very different life cycles. Some life cycles, like some insects, take only a few days to complete. Others, like most mammals, have life cycles that take many years. Animal life cycles also differ in their number of stages. There are 3 main types of animal life cycles.

Type 1: Egg ➡ Young ➡ Adult

Animals that go through this life cycle look a lot like their parents when they are born. They grow and change as they get older and eventually reproduce just as their parents did.
Example; the Life cycle of a chicken 

1.Female chicken lays a  fertilized egg.

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2.chick hatches from the egg after about 20 days. It grows larger and develops feathers.

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3.Chick grows and develops into an adult chicken.

Like most mammals, the first stage of the life cycle takes place inside the mother's body in some animals. These animals give birth to live young that then grow and change to look like their parents.

Type 2: Egg ➡ Larva ➡ Pupa ➡ Adult

Animals with this type of life cycle do not look like their parents when they are young. They are called larva at this early, immature stage. Their life cycle involves a special stage, called the pupa stage, where their bodies change to look more like their parents.
Example: Life cycle of a butterfly

1.Fertilized egg laid by female butterfly.

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2.A larva, called a caterpillar, hatches from the egg.

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3.Larva grows, changes, and forms a cocoon (pupa).

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4. Pupa emerges as a butterfly.

Type 3: Egg ➡ Larva /Nymph ➡ Adult

 
Animals with this type of life cycle often look different from their parents when they are young. As they get older, their bodies go through several changes. As they grow and change, they start to look more and more like their parents.
Example: Life cycle of a cockroach.

1.Egg laid by female cockroach.

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2.A baby cockroach called a nymph hatches from the egg. The nymph resembles the adult but is smaller and without fully developed wings.

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3. the nymph grows and molts several times as it grows. Eventually, it develops into an adult cockroach.

Plant life cycles

 The life cycle of a simple plant 

1.Sperms are released by the male organ of the plant.

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2.Sperms are carried by water to female eggs, where fertilization takes place.

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3.Each fertilized egg then develops and forms a capsule that contains Spores.

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4. When the capsule opens, the spores are released into the air or are carried away by water.

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5.With the right conditions, each spore will grow into a new simple plant.

The life cycle of a fern 

1.Spores found on the underside of the fronds (leaves )and released and fall to the ground.

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2.Each spore develops into a new plant called a Prothallium .

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3.The new plant does not look like a fern at all. It is a small heart-shaped plant with structures that produce sperms and eggs.

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4. Sperms are then released and are carried by water to eggs, where fertilization occurs.

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5.A fertilized egg then develops new fronds and grows into a new fern.

The underside of fern leaves has spore-containing sacs called sporangia. The sporangia dry up and split, releasing the spores.

The life cycle of a cone-bearing plant 

1.The male cone releases pollen grains which travel through the air to the female cone.

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2. The fertilized egg develops into a seed with a small plant (embryo) inside.

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3.When the seed is mature, the female cone opens, and the seed drops to the ground or is carried away by air to a new place.

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4. The seed then develops into a mature plant.

The life cycle of a flowering plant

1. The male part of the flower, called the anther, produces pollen grains carried to the female part of the flower, called the stigma.

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2.Fertilization occurs when a pollen grain moves down a tube, called the style, to the ovary.

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3. The fertilized egg in the ovary then develops into a seed. The ovary expands around the developing seed forming a fruit.

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4.The seed is dropped to the ground or carried by wind or animals to a new place.

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5. With the right conditions, the seed grows into a new plant.

A kiwi fruit is an example of a fleshy fruit. It is usually eaten by animals which helps to spread the seeds.
 

A pod is an example of dry fruit.The pod splits along the side and releases the seed.