Welcome to another session of Science Files. This presentation is from File 2 which is for class 2.

The Unit is named ‘Going in Cycles’ This lesson is focused upon the repeating patterns of

things or events which occur naturally or artificially.

After reading this lesson the children would know that:1. The repeating patterns can be shown in a

cycle.2. There are many events and phenomena which

occur in cycles.3. The repeated sequence of events that occur

for indefinite time constitutes cycle

If this pattern has to repeat itself indefinitely, then the sequence of the four given figures can be shown in a

cycle.What will come after square? A star!

Next figure to come will be a sphere and so on..

A pattern that repeats itself again and again is called a

cycleYou can tell what comes next in a cycle.

Look at the following pattern:There is a star, a circle, a triangle and a square.

Teaching the lesson

Now the pa tte rn is comple te .Now the pa tte rn is comple te .

Can you fill the blanks correctly?

Now see care fully::

Can you see theCan you see the p a tte rn p a tte rn herehere ? ?

A pa tte rn tha t repea ts itse lf aga in and aga in

can be shown in a c y c le .c y c le .

c y c lec y c le

cocoon

eggs

butterflycaterpillarThis is the life cycle of butte rfly.

It goes like this :eggsca te rpilla rcocoonbutte rfly

How Is A Butterfly Formed?

This is a lso a cycle .

Do you know of some things a round you tha t happen in cycles?

Do you follow a cycle in your da ily routine?

Show the seasons in a cycle . Show a day and night in a cycle .

Winter

Spring

Summer

Autumn

A year constitutes a cycle of seasons

Can you see any link be tween these pictures?

Can you expla in each picture?

What is happening?

WinterSpring

SummerAutumn

Winter again!The seasons come after one another in a given sequence. So there is said to be a cycle of seasons in a given period of time

Here is another cycle____

The Water CycleThe Water CycleSee how wate r moves in na ture .

Sun heats up big and small water bodies on the Earth. Water evaporates and rises up to sky. Cools down and condenses into clouds. Comes back to Earth as rain, hail and snow. Goes into the Earth as run off water.

Sunrays heat up water bodies on EarthWare evaporates

Water vapours rise up, cool down on the sky

to form clouds.Then come back to Earth

as rain.

ra in Water evapora tes

Water body

water evapora tes

Rain wa te rsoaks into soil

ground wate r

runoff

cloudssun

Spawn

small tadpole

big tadpole

young frog with ta il

Adult frog

Life cycle of Frog

Let the children see the pictures and invite them to make s tories about diffe rent seasons .