Germination of Seeds for Class 3 Science

Seeds are the tiny structures that develop new plants on germination. The plants reproduce through seeds. These seeds are dispersed to various places which leads to growth of beautiful plants around.
This concept explanation will introduce the learners to seeds of plants.

After reading the concept, students will be able to:

Identify the parts of a seed.
Explain the meaning of seed dispersal.
Give examples for types of seeds.
Name different plant habitat.
Brief the stages of seed germination.

Each concept is explained to class 3 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Germination of seeds provided in PDF format.

What Are Seeds?

Seeds are tiny structures that enclose the baby plants in them.
They are formed on the maturation of flowers.
Some seeds are enclosed in fruits. Example: Mango, banana, and litchi.
Some seeds are not present in fruits; instead, they are present in cones. Example: Conifers, pines, and cedars.
Seeds have a dry outer covering and can remain intact in harsh weather. They germinate and grow into new plants when suitable conditions are available.

Parts of a Seed:

Seeds vary in number, size, shape, and colour in different plants.
Most of the seeds consist of the following parts—

a.Seed Coat:

- It is the outermost part of a seed that protects it from any injury.
- The seed coat can be smooth, rough, or hairy.

b.Embryo:

- The embryo is the tiny baby plant found inside the seed.
- It develops into a new plant after germination.
- The embryo can be divided into radicle and plumule, which form the root system and shoot system, respectively in the new plant.

c.Cotyledon:

- Cotyledons are also called seed leaves.
- Here, the seeds store food. As seeds cannot perform photosynthesis, the food stored in cotyledons helps them germinate and develop a root and shoot system.
- Some seeds have two cotyledons, like pea, gram, and mango, whereas others have one cotyledon, like wheat and rice.

Stages of Seed Germination:

The process of the growth of a plant (in this case, the seedling) from the seed is called germination.
Seeds germinate in the presence of suitable environmental conditions. They require air, water, soil, and sunlight for germination.
If a seed is sowed too deep in the soil, it will not germinate.
On absorbing enough water, the seed swells up, leading to the seed coat's bursting.
It gives rise to a baby plant called a seedling.
The radicle grows into the root system.
The plumule grows into the shoot system.

Types of Seeds:

Seeds can be categorised into different groups based on specific factors.

a.Based on Edibility:

- The seeds which are suitable for consumption are called edible seeds.
  
  Examples: Wheat, rice, fennel, coriander, pea, etc.
- The seeds which are not suitable for consumption are called non-edible seeds.
  Examples: Litchi, apple, neem, pear, etc.

b.Based on the Number of Cotyledons:

- The seeds which have two cotyledons are called dicots.

Examples: Gram, moong, pea, rajma, etc.

The seeds which have one cotyledon are called monocots.

Examples: Rice, wheat, maize, etc.

Seeds Used as Food:

a.Pulses: Pulses can be eaten raw and soaked.

Examples: Moong, rajma, gram, pea, etc.

b.Cereals: Cereals make the major portion of our food. They cannot be consumed raw and are cooked before consumption.

Examples: Rice, wheat and barley.

c.Spices: Some seeds are used as spices. Spices add flavour and colour to food.

Examples: Fennel, fenugreek, cardamom, mustard, pepper, and cumin.

Dispersal of Seeds:

Dispersal stands for the scattering of seeds to far-off places.
It is necessary so that the plant species grow in various places.
The absence of dispersal may lead to the following situations—

The plant species would be limited to certain areas only.
The new plants will grow near the mother plant, leading to overcrowding and competition for food, light, and space.

S.no.	Method of Dispersal	Examples
a.	By wind	Dandelion, Cottonweed, Cattail, Orchid.
b.	By water	Mangroves, Coconut, Lotus.
c.	By animals	Watermelon, Litchi, Guava, and Mango.
d.	By explosion	Ladyfinger, Pea.

New Words:

Photosynthesis: The process by which plants prepare their food using sunlight, water, and carbon dioxide.

Edibility: The property of being suitable to eat.

Explosion: (in this case) Bursting open of something.

Did You Know?

Baby leaflets grow towards the sunlight above the soil, and the baby root system develops towards the bottom away from the sunlight. It happens because leaves respond to sunlight, and roots respond to the gravity of Earth.
Animals often eat seeds that come out through the animal’s poop. These seeds drop to the ground, and new plants come out from them.
The largest seed called Coco-de-Mer, also called the double coconut, grows only in Seychelles. It weighs up to 30 kg.