Bal Bharati Public School Navi Mumbai Sub- Science

Class-V

Lesson -1

Prepared by Bharathy Prabhakar

L-1 Plants: Increasing in Numbers

Importance of Plants Plants are major part of nature. They give us many thing like-

Cereals vegetables Fruits Rubber

Coffee Tea

Plants also help to give fresh oxygen n help in soil conservation.

Structure of a seed

A seed and its parts

A seed has three parts-1.Seed coat 2.Seed leaves 3.An embryo

Functions

1.A seed coat protects the embryo. 2.Seed leaves supply the stored food to the growing

embryo. 3.The baby root develops first and emerges out of the

seed coat and later the baby shoot comes out and grows towards the sun.

The seed leaves supply food the leaves are able to prepare their own food

A micropyle is a small opening in the seed which helps to absorb water and make the seed coat soft so that the baby root and shoot can emerge(come out) easily.

Types of seeds

1.Monocot seeds

•Have only one cotyledon

2.Dicot seeds

•Have two cotyledons

Seed Germination

The process of development of a seed to a seedling is called seed germination.

Conditions for GerminationThe four conditions needed for a seed to germinate are-

1.Air to breathe2.Water to make the seed coat soft.3.Warmth for the cells in a seed to be active.4.Sufficient space to grow into a healthy plant.

Dispersal of seeds

The process of scattering of seeds away from the mother plant so that all seeds get enough light ,water, air and space to grow.

The seeds are dispersed by nature agents like wind,water,animals and explosion.

Agents of seed dispersal

1.Wind 2.Water 3.Animals 4.Explosion

Wind dispersal Seeds dispersed by wind are light and have

hair or wings.These features help seeds to be carried away by wind.Ex

cotton dandelion maple

Water dispersal Water dispersal-The seeds like coconut are light

and have fibrous outer covering that enable the seed to float on water easily.Lotus and water lily seeds are spongy and light.Ex

coconut Lotus

Animal dispersal Animal dispersal-some seeds have hooks

and spines which stick to the furry hair of animals like dogs ,squirrels .Some birds swallow the seeds of juicy fruits and disperse the seeds.

Explosion of seeds Explosion of seeds: Some seeds explode or burst

open when they dry and scatter the seeds.ex

pea pod, balsam seeds

Vegetative PropagationAll new plants not only grow from seeds but also from certain other parts like roots,stem and leaves.

New rose plants grow from stem cuttings

Potato n ginger grow from eyes or buds on it.

Sweet potato grows from roots

Bryophyllum from the notches of the leaves.

Examples

CropsPlants of one kind grown in a particular area during a particular period are called crops.example rice,wheat,bajra maize etc

Types of crops•Grown from Nov to

April•Ex-wheat ,gram

1.Rabi

•Grown from June to Oct•Ex-Rice,maize2.Kharif

Type of soil required Wheat

(Punjab n UP)

Jowar,Bajra

Rajasthan

Cotton

Maharasthra

Tea and coffee

Ooty,Coorg,

Maize

Sandy and

Irrigated soil

Sandy soil Black soil Moist soil, and

hill slopes

Dry soil and

plains

Agriculture Plants need to be

grown in large scale to feed the entire population of a country.

The practice of growing plants in large numbers is agriculture.

.

For healthy crop Use healthy and ripe seeds for sowing.

Prepare the soil properly

Add only required quantity of manure and fertilizers

Irrigate the soil well.

Spray insecticides and pesticides on the crops at the right time.

Protection of crops

1.Grazing animals

2.Pests &Locusts

3.Plant diseases

Storage of seedsWe should Store seeds in Airtight & sealed

containers.

Let us meet

M S Swaminathan- He is an Indian agriculture scientist.He is also known as ‘FATHER OF THE GREEN REVOLUTION IN INDIA.’He introduced high yielding varities of wheat.He was honoured with first world food prize by United Nations in 1987.

Links For seed germination--

https://www.youtube.com/watch?v=TE6xptjgNR0

Reproduction in plants—

https://www.youtube.com/watch?v=KdZ2blF2CuM