Germination and Growing

8/3/2019 Germination and Growing

1/18

Germination and Growing

What do seeds and plants need?

Our class investigation January /

February 2012


2/18

Germination

Thinking back over what we had learnt in the

past we listed the things we thought a seed

would need to germinate. They are:

DO NEED DONT NEED

Warmth Soil

Moisture Carbon dioxide

Oxygen Light


3/18

Germination

To test our ideas we planted some cress

seeds and broad beans.Cress seed

on wet cottonwool.

They were in

a box in the

cupboardwhere it

would be

warm and

dark.


4/18

GerminationWe put the broad beans in jam jars, held inplace with a wet paper towel. They alsowent into a box in the cupboard.


5/18

Germination

We put one dishof cress and onebean outside.

They got littlewarmth as it wasJanuary; light and

dark and lots ofwater as it rainedon them and filledtheir containers.


6/18

Germination

We also planted

some cress and a

bean in one of ourplanting beds.

They got little

warmth as it was

January; no lightbut plenty of

moisture.


7/18

Germination results

After 3 days the cress

seeds in the box in the

cupboard had

germinated.

They had small yellowy

shoots.

The ones outside

showed no signs of

germination.


8/18

Germination results

To germinate, the seeds did NOT need light

or soil.

Our test could not demonstrate it but wedont think they need CO2 either.

Plants not seeds use light and CO2 for

photosynthesis.

Seeds do not photosynthesise, they just

respire, so they need oxygen.

They DO need warmth and moisture.


9/18

Growing

We talked about where we could put our

seedlings to test what they need for healthy

growth.

We had 5 ramekin jars and the table shows

what we did with them.


10/18

Growth1 On a window sill, kept moist

with water.

Has warmth, light, water,

oxygen and CO2 .

2 On a window sill, but nomore water given.


oxygen and CO2 .

3 In the box in a cupboardwith water supplied.


oxygen and CO2

4 In the dark, outside (in thesandpit). Has warmth, light, water,oxygen and CO2

5 Outside Has warmth, light, water,oxygen and CO2 .


11/18

Growth results (4 days after germination)

Seedlings hadgrown vigorously.Leaves are a rich

green colour.Plants about3.5cm tall.

On a window sill, kept moist

with water.


oxygen and CO2 .


12/18


Seedlings had grown

quite vigorously but

not as tall as those

with extra water.

Plants only about

2.5cm tall.

Leaves are a darker

green colour.

On a window sill, but no more

water given.


oxygen and CO2 .


13/18


Seedlings werereally tall, spindlyand yellow, about5cm tall.

They have grownlike this becausethey are hunting forlight. They are

etiolated.

In the box in a cupboard with

water supplied.


oxygen and CO2


14/18


Seedlings had notchanged since theygerminated.

They had not grown

because it was toocold.

They did not turngreen as there was

no light.

In the dark, outside (in the

sandpit).


oxygen and CO2


15/18


Seedlings had notchanged since theygerminated.

They had not grown

because it was toocold.

They did not turngreen even though

there was light.

Outside Has warmth, light, water,

oxygen and CO2 .


16/18

Conclusions

1. Our results show that to germinate a

seed requires warmth, and moisture. (It

also requires oxygen but we could not

show that.)

2. After germination, to grow vigorously, a

seedling needs warmth, moisture and

light, (Plus oxygen and CO2)


17/18

Conclusions

3. A seedling that does not have light will

grow tall and spindly, looking for light. It

will be unable to produce chlorophyll so

the leaves are yellow, not green.

4. If warmth is removed there is no growth

at all. But the seedling remains alive.


18/18

Conclusions

5. A cress seedling that has not had light orwarmth can respond very quickly whenthey are provided. It begins to grow and

turns green.

6. A seedling that has light and warmth but

no moisture will grow for a time but thenwilt and die. It does not recover whenwater is provided.

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Germination and Growing