Unit 5B Life cycles

Through this unit children learn that plants and animals reproduce as part of their life cycle and that in every life cycle there are distinct processes and

stages. They should begin to understand how reproduction is important to the survival of the species.

Some of the work in this unit is likely to be undertaken in relation to the school's programme for PSHE.

It is recommended that this flipchart is used in conjunction with the QCA

Scheme of work for Science

Unit 5B Life Cycles

Life Cycles

Unit 5B Life Cycles

Life Cycles

In this unit you will learn about:

w why plants produce fruits and seedsw how seeds are spreadw what seeds need to groww how pollen is spreadw flower parts and how seeds are madew how the stages in a plant life cycle fit togetherw the stages in a human life cyclew how humans compare with other animalsw life processes

Where did the fruits grow from?What will happen to the fruits?Why are the fruits important to the plants?

Unit 5B Life Cycles

Not all fruits are the sort that we eat.

honeysuckle flower

honeysuckle fruit developing

fruit of a poppy

Unit 5B Life Cycles

Fruits and seeds

Apple Tomato

Unit 5B Life Cycles

Can you see the seeds?

seeds

seed head

holes

Have you heard of the pepper pot effect?

Unit 5B Life Cycles

How are poppy seeds spread?

How are these seeds spread?

Unit 5B Life Cycles

sycamore goose grass cleavers

How are these seeds spread?

Unit 5B Life Cycles

Why do seeds need to be dispersed?

Unit 5B Life Cycles

Why do plants produce so many seeds?

See next page.

Dispersal

Seeds need to be dispersed so that they arespread out, away from the parent plant.This means they will have enough space to grow.The roots need space to collect water. The leaves need space to collect sunlight.If the seeds are dispersed they will not be competing with each other when they grow.Each new plant will have more chance to get enough water, sunlight, air and spaceto grow healthily.

Unit 5B Life Cycles

Rub and reveal.

WindAnimals

Explosion

Sort the seeds

Unit 5B Life Cycles The three main agents of dispersal

Wind dispersal

Wings Parachute "Pepper pot" effect

Sort the seeds.Can you think ofother seeds for each section?

Unit 5B Life Cycles

Dispersal by animals

Seeds get eaten Seeds get storedSeeds get stuck in fur

Sort the seeds

Unit 5B Life Cycles

InvestigatingGermination

What do you think a seed needs to make it germinate?

When seeds have been dispersed they need to germinate (start to grow). This often happens in the spring. Why do you think this is?

Unit 5B Life Cycles

What do you think seeds need to germinate?

Ideas:

Unit 5B Life Cycles

ACTIVity link

Investigating which factors affect germination

Prediction:Which of these factors do you think will affect germination? Give a reason for each one.

1. Water

2. Light

3. Temperature

4. Soil

5. Air

Unit 5B Life Cycles

Controlling the variables - making it a fair test

This investigation has lots of variables (factors that we want change to see if they affect germination).Variables: water, light, temperature, soil, air

We can't change more than one of these variables at a time. We need to set up lots of pots and only change one thing each time.

We also need to set up one pot to compare each of the other pots with. It is called the control. We only change one thing in each of the other pots.

Unit 5B Life Cycles

Six pots are set up. They are all left in darkness apart from pot 2.

dampcompost

wetcompost

dampcompost

dampkitchentowel

drycompost

water

cressseeds

Left in fridge

In darkness

1. Control 2. Not in darkness 3. No water

4. No compost 5. No air 6. No warmth

In darkness

In darkness In darkness

dampcompost

Unit 5B Life Cycles

Results:

Conclusion:

Unit 5B Life Cycles

Unit 5B Life Cycles

What happens to seeds after they have germinated?

If the seedlings have the correct conditions they will grow into healthy plants.

Later the plant will produce flowers. These produce pollen which needs to be transfered from one plant to another.

How is it transfered - can you think of the two main ways?

insect pollinationwind pollination

Unit 5B Life Cycles

Flower parts

Flowers come in all different shapes and sizes but they have the same basic parts.

A male part which produces the pollen.

A female part which produces the eggs (ovules).

A sticky part that pollen sticks to.

Petals.

stamenovary stigma

Match up the names with the parts.

Unit 5B Life Cycles Flower parts

Use the next few pages to practise identifying the different flower parts.

Then collect some flowers of your own and see if you can find the different parts.

How will wind pollinated flowers be different? See if you can find any.

ovule pollen stigma ovary stamen stem petal

Label the poppy Unit 5B Life Cycles

1

2

3

4

5

6

7

Label the buttercup

pollen stigma ovary stamen sepal petal

Unit 5B Life Cycles

1

2

3

4 5

6

Label the flower

ovule pollen stigma ovary stamen petal sepal

Unit 5B Life Cycles

style

1

2

3

4

5

6

7

8

Unit 5B Life Cycles

Pollination and Fertilisation

Pollination is the transfer of pollen from the stamen of a flower to the stigma of another flower.The pollen grows down from the stigma to the ovary.Fertilisation is the joining of the pollen and the egg (ovum). A fertilised egg can then form a seed.

Use the diagrams to show what happens in pollination and fertilisation.

What are the functions of the parts?

petal

sepal

pollen

stigma

stamen

ovary

ovule

fertilises the eggs (ovules)

attracts insectsfor pollination

protects the flowerbefore it opens

pollen sticks to it

male partmakes pollen

female partbecomes fruit

(egg) becomes seed

makes nectar toattract insects

nectary

Unit 5B Life Cycles

Note: Inside the ovule is the egg cell (ovum) which is fertilised by the pollen.The ovule then becomes the seed.

Pollination is the transfer of _________ from the _________

to the __________. Pollen is carried by _________ or by

__________. When this has happened the pollen grows down

into the ___________ and joins with an _________(ovum).

This is called ___________. The ovum will become a ______

and the ovary will become the _________.

seed insects egg stamen stigma

ovary fruit fertilization wind pollen

Unit 5B Life Cycles Pollination and Fertilisation

Unit 5B Life Cycles Observing pollen

Collect some stamen and pollen from different species of plants.

Observe them carefully with a microscope or hand lens.

Can you see any differences?

How might these differences be useful to the plants?

stigma

stamen

pollen grains

Put the stages in the plant life cycle in the correct order, starting with germination.

growth flowering pollination

fertilisation

dispersal

fruit formation germination

Unit 5B Life Cycles

1

2

3

45

6

7

Look at the next page to check.

Plant life cycle

growth

flowering

pollination fertilisation

dispersal

fruit formation

germination

Unit 5B Life Cycles

1

2

3

45

6

7

toddler baby child adolescent senior citizen adult

Stages in the human life cycle

Put the pictures in the correct order then match up the labels.

Unit 5B Life Cycles

toddler baby child adolescent senior citizen adult

Stages in the human life cycle Unit 5B Life Cycles

How long does each stage last?

What changes take place during each stage?

ACTIVity links; Growth: Growth Graphs

Unit 5B Life CyclesStages in the human life cyclew Pregnancy 9 monthsw Birthw Baby 0 - 12 monthsw Toddler 12 months - 3 yearsw Child 3-12 yearsw Adolescent 12-18 yearsw Adult 18 years onwardsw Death 70 years or more

The exact times for the stages will vary for each individual person.

Unit 5B Life CyclesThe human life cycleHuman children are extremely dependent on their parents. Bringing up children is a big commitment.

1. Human babies are born completely helpless.2. Babies remain helpless for a long time.3. They are unable to:w Feed themselvesw Clean themselvesw Walkw Keep themselves warmw Protect themselves4. They need parental care for many years as they grow.5. Children live with their parents until adulthood (approx 18 years) or longer!

The decision to have a baby is a very important one,what needs to be thought about beforehand?

Differences between humans and other animals

Pregnancy - A human baby develops for 9 months inside the mother's womb. This is called the gestation period.

A human child needs to be cared for by its parents for about 18 years until it becomes an adult.

Find out how long these stages take in other animals.

Unit 5B Life Cycles

Life processes

Unit 5B Life Cycles

Reproduction is just one of the life processes that all living things need to carry out in order to survive.

Can you think of the other life processes?

There are seven altogether.

Reproduction an important life process.

Why is it important for plants and animals to reproduce?

Some animals such as pandas, tigers and cheetah are facing extinction. How can they be helped?

Look at the next page to check.

Look at the clues. Match up the correct name for each life process.

Excretion

Movement

GrowthSensitivity Reproduction

Respiration

Nutrition

Unit 5B Life Cycles

1 2 3

4

5

6 7

Excretion

Movement

Growth

Sensitivity

Reproduction

Respiration

Nutition

Can Mrs Gren help you to remember all the life processes?

Rub and reveal.

Unit 3B Helping plants grow well