Primary Upper Block Cycles: Reproduction in Plants ... · Primary Upper Block Cycles: Reproduction in Plants Introduction to Notes 1 Okay. Don’t worry! The fire is actually good

PSUB | Cycles | Notes 1

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Primary Upper Block Cycles: Reproduction in Plants Introduction to Notes 1

Okay.

Don’t worry! The fire is actually good for us. Everyone, get

ready to leave the cone!

OOPS!

Big sister, Are we ready

yet?

Yes, dear. We will be separated once we leave this place. Remember to

take good care of yourselves and open

the parachute when you start to fall!

Big brother, why is it so

hot?

Oh no! There is a fire outside!

We are all going to die!

Little sister, don’t open the parachute

first. You open it only when you start to fall

downwards.

The scouts have all gone to sleep in their tents after a campfire but they did not put out the fire…

The fire grew bigger and closer to a pine tree.

Inside a pine cone on the tree… We know children like comics! Using that to our advantage, we introduce complicated concepts in a fun way.



BOOM BOOM

Bye, big brother!

Where are the rest? Where am

I?

Take care!

I’m falling!

It’s almost time now. Everyone, please get into

your positions!

A few years later, the little seed has grown into a new pine tree…

The seeds left the cone and began their journeys…



In today’s lesson, you will learn to: identify the parts of a flower and state their functions

describe the sequence of events in the sexual reproduction of flowering

plants

compare sexual reproduction in flowering plants and that in humans

identify the methods of dispersal of seeds in flowering plants

describe the characteristics of fruits/seeds which make them suitable to be

dispersed by the various methods

state the conditions needed for seed germination and describe the sequence

of events during this process

There are plants which have developed behavioural adaptations in order to survive in the harsh environment where they live in. An example is the pine tree which disperses its seeds by fire. The cones of the pine tree which contain the seeds are usually closed. They only open up when they experience a critical high temperature, for example, during a forest fire. Upon reaching the critical temperature, the cones open up and release the seeds for dispersal. The seeds which are dispersed then settle in another place before they germinate and grow into new plants.



RECAPITULATION All living things are able to reproduce to ensure the continuity of their own kind

(prevent extinction).

There are two types of reproduction.

(a) Asexual reproduction

- Only one parent is involved.

(b) Sexual reproduction

- Two parents are involved.

TYPES OF REPRODUCTION IN PLANTS In sexual reproduction, the male and female parts of plants are involved.

In asexual reproduction, only one parent is needed.

Primary Upper Block Cycles: Reproduction in Plants Notes 1

Plant Reproduction

Sexual Reproduction

seeds

Asexual Reproduction

artificial vegetative propagation

with the help of Man without the help of Man

spores natural vegetative reproduction

(from other plant parts)


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SEXUAL REPRODUCTION IN FLOWERING PLANTS In sexual reproduction, the male and female parts of the plant are involved in producing a new plant.

The new plant is not identical to the parent plant.

PARTS OF A FLOWER The flowers of flowering plants contain the parts for reproduction.

FLOWER STALK

SEPAL protects the flower

STAMEN male part

of the flower

STIGMA Pollen grains are received here.

STYLE connects the stigma to the ovary

OVARY (grows into a fruit)

PISTIL female part of the flower FILAMENT

to hold the anther out

OVULE (grows into a seed) Each ovule carries a female

reproductive cell (egg).

ANTHER - It contains four pollen sacs. - Each pollen sac carries many

male reproductive cells (pollen or pollen grains).

Visuals help our students to grasp the concepts quickly.



HOW DOES SEXUAL REPRODUCTION OCCUR IN FLOWERING PLANTS?

In sexual reproduction of plants, the sequence of events is:

pollination fertilisation seed dispersal germination

1. Pollination : pollen is transferred from the anther to the stigma

2. Fertilisation : the pollen fertilises the egg

3. Seed dispersal : the seeds are dispersed away from parent plant

4. Germination : the seed grows into a new plant

POLLINATION The process by which pollen is transferred from the anther of a flower to the

stigma is called pollination.

Pollination can be carried out by wind or animals.

CASE STUDY A

WIND-POLLINATED FLOWERS Plants that are usually pollinated by wind usually have small, dull

flowers and/or unscented flowers without nectar.

These flowers are not attractive to insects.

Their pollen grains are small, smooth and light which allows them to be blown

away by the wind easily.

Wind-pollinated flowers have long

filaments which can be easily shaken

so that the wind can carry the pollen

away.

They also have large, feathery

stigmas that provide a large surface

area to catch the pollen in the air.

Example: grass



As much as we would love to show you everything,

we cannot be showing you the best.

Do drop by any JustEdu centre to view the full set!



Do drop by our centre to view the full set of materials.



SEED DISPERSAL Plants disperse their seeds to:

(a) avoid overcrowding and competition for resources with parent plants

(b) ensure the survival of the species

Plants disperse their fruits/seeds in the following ways:

(a) by water

(b) by wind

(c) by animals

(d) by splitting/explosive action

CASE STUDY C

DISPERSAL BY water

Plants that disperse their fruits/seeds by water grow near water bodies like rivers

and oceans.

The fruits of these plants have waterproof coverings or fibrous husks that trap air

and enable them to float on water.

When the fruits reach a favourable environment, the seeds inside the fruits will

germinate into a new plant.

Examples: coconut, lotus, mangrove, nipah, pong pong

coconut lotus









Dispersal by splitting followed by wind Some plants disperse their seeds by splitting without an explosive force. Their seeds are then

dispersed by wind. Examples: African tulip, kapok (cotton plant)

kapok African tulip



CASE STUDY H

PROCESS OF GERMINATION

The root emerges from the seed coat and grows downwards.

first root

1

The shoot then emerges and grows upward out of the soil. The seed coat may fall off.

shoot

seed coat

2

first leaves

The shoot grows taller and the first leaves start to develop. The roots also grow longer.

3

The first leaves spread out. They start to make food (or photosynthesise) for the plant. The seed leaves eventually fall off.

first leaves

seed leaves

4



LIFE CYCLE OF A FLOWERING PLANT

pollination and fertilisation occur

dispersal of fruits and seeds

seed lands on fertile soil

sufficient warmth, oxygen and water are present

root emerges

first shoot emerges and grows out of soil

first leaves emerge first leaves spread out and start

to photosynthesise, seed leaves wither and fall off

young plant continues to grow

plant matures and produces flowers



COMPARISON OF SEXUAL REPRODUCTION OF HUMANS AND FLOWERING PLANTS

Human Flowering Plants

Name of female reproductive cell egg egg

Name of male reproductive cell sperm pollen

Where does fertilisation occur? oviduct of the female ovule in the ovary

How is the new organism formed? When the nuclei of the male and female

reproductive cells fuse.

Summary

1. F________________ plants can reproduce from seeds.

2. The four processes in the sexual reproduction of plants are p________________,

f___________________, s_____________ d___________________ and

g________________.

3. M____________ and f______________ parts of the flowers can be found on either a

single flower or separate flowers.

4. The female parts of the flower are the s____________, s______________,

o____________ and o______________.

5. The male parts of the flower are the f______________ a thin stalk and the

a_____________.

6. The anther contains p______________ s_____________, each of which carries

many male r______________________ cells called pollen.

Summarising the chapter helps our students to recap what has been taught during the lesson!



7. The process by which the pollen is transferred from the anther of a flower to the

stigma is called p____________________.

8. Plants that are pollinated by animals usually have b_______________

c_______________ flowers or flowers which are s______________ to

a______________ animals.

9. I______________ help in pollinating flowers when they look for nectar.

10. The process by which the n______________ of the pollen fuses with the egg to

produce a f_______________ egg is called f______________________.

11. After f_______________, the ovary develops into a f_________________ while the

ovules develop into s______________.

12. The fruit carries and p_______________ the seeds.

13. The seeds are released when the fruit is r_____________.



Primary Upper Block Cycles: Reproduction in Plants Practice 1

Our notes are complemented by a comprehensive Practice paper.

A typical practice will have 15 multiple-choice questions and 5 open-ended questions for our students to attempt. This is then followed by an ‘ACE’ question to further enhance the understanding of our students. This proprietary technique is uniquely found at JustEdu and has helped numerous students to break down and analyse the question before attempting. Furthermore, this same technique can be used to answer multiple-choice questions as well. An example of an ‘ACE’ question is given next:



Use the ACE Question Answering Technique to answer the question below.

Dave sprinkled some pollen grains onto two other flowers from the same type of plant. The diagram below shows where the pollen grains have landed on the flowers.

(a) Which flower is more likely to develop into a fruit? (1m)

(b) Explain your answer to (a). (2m)

Circle the important information in the question. Study the diagram and write down in the space below the information that you can obtain.

Topic: _____________________________________________________________ Concepts:

A flower is successfully __________________ when pollen grains from the same

__________________ land on the __________________ of the flower.

A pollen tube is formed after pollination to transport the __________________

towards the ovary from the __________________.

The pollen __________________ the ovule in the ovary.

STEP 1: ANALYSE THE QUESTION

STEP 2: CONCEPT ANCHORING

pollen grains pollen grains

Flower A Flower B



The ovary will develop into a __________________ upon fertilisation of the

ovules.

(b) Key points: ______________________________________________________

______________________________________________________

Link the requirements in the question with all the keywords listed. You may use arrows or a simple concept map to help you.

Answers: (a) Which flower is more likely to develop into a fruit? (1m)

________________________________________________________________

(b) Explain your answer to (a). (2m) ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES



Use the ACE Question Answering Technique to answer the question below.

Dave sprinkled some pollen grains onto two other flowers from the same species. The diagram below shows where the pollen grains have landed on the flowers.

(a) Which flower is more likely to develop into a fruit? (1m)

(b) Explain your answer to (a). (2m) Circle the important information in the question. Study the diagram and write down in the space below the information that you can obtain.

Flower A: all of the pollen grains landed on the style Flower B: one pollen grain landed on the stigma, one landed on a filament

Topic: _____________________________________________________________ Concepts:

A flower is successfully __________________ when pollen grains from the same

__________________ land on the __________________ of the flower.

A pollen tube is formed after pollination to transport the __________________

towards the ovary from the __________________.

The pollen __________________ the ovule in the ovary.

STEP 1: ANALYSE THE QUESTION

STEP 2: CONCEPT ANCHORING

Answers

pollen grains pollen grains

Flower A Flower B

Reproduction in plants

pollinated

pollen

stigma

fertilises

species stigma



The ovary will develop into a __________________ upon fertilisation of the

ovules.

(c) Key points: ______________________________________________________

______________________________________________________

______________________________________________________

Link the requirements in the question with all the keywords listed. You may use arrows or a simple concept map to help you.

Answers: (a) Which flower is more likely to develop into a fruit? (1m)

________________________________________________________________

(b) Explain your answer to (a). (2m)

STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES

fruit

Pollination, pollen grain land on stigma, pollen transported to ovary, fertilise ovule, ovary develop into fruit.

Pollen grain lands on stigma

Pollen tube grows to transport pollen from stigma to ovary

Pollen fertilises ovule in ovary

Ovary develops into fruit

Flower B

Pollination occurs

Flower A

Pollination does not occur

Flower B

Only Flower B was successfully pollinated as a pollen grain had landed on the stigma in Flower B but not Flower A. Upon pollination, a pollen tube will grow to transport the pollen towards the ovary (½m) where it will fertilise an ovule, resulting in the ovary developing into a fruit.

Answers

PSUB | Cycles | Concept Map (for student’s reference only)


Primary Upper Block | Cycles: Reproduction in Plants | Concept Map

with sufficient warmth, water and oxygen, the seed will be able to germinate.

2) filament

1) anther

bryophyllum, begonia

banana, pineapple

potato, ginger

carrot, turnip

fern

By spores

Plants reproduce to ensure the continuity

of their own kind.

Sexual reproduction

Reproduction of Plants

Asexual reproduction

two parents needed only one parent needed

By seeds

moss

Fertilisation occurs when

the nucleus of the pollen grain enters the ovule and fuses with the egg to form a fertilised egg.

Male parts

Sexual Reproduction in Flowering Plants

1. Pollination

Structure of a flower

Female parts

Sequence of events

2. Fertilisation 3. Seed dispersal 4. Germination

Pollen grains are transferred by

wind or animals from the anther to the stigma.

a) By wind: angsana, shorea

b) By water: coconut, pong pong

c) By animals: mango, love grass

d) By splitting: rubber, balsam

a) Root grows downwards.

b) Shoot grows out of soil.

c) First leaves develop and the plant is able to photosynthesise.

1) stigma

Underground stems

Underground roots

Suckers

Leaves

3) ovary (develops into a fruit)

4) ovule (develops into a seed)

2) style

At the end of each topic, students are equipped with a concept map and a list of keywords and phrases to reinforce the key concepts of the topic.

PSUB | Cycles | Concept Map (for student’s reference only)


List of Keywords and phrases

animal-pollinated flowers

anther

asexual reproduction

avoid overcrowding and competition

dispersal by animals

dispersal by splitting

dispersal by water

dispersal by wind

ensure survival and continuity of their own species

explosive action

fertilisation

fibrous husks

filament

germination

ovary develops into a fruit

ovule develops into a seed

pollen grains

pollination

reproduction by leaves

reproduction by seeds

reproduction by suckers

seed dispersal

sexual reproduction

stigma

style

underground stems

wind-pollinated flowers

wing-like structure

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Primary Upper Block Cycles: Reproduction in Plants ... · Primary Upper Block Cycles: Reproduction in Plants Introduction to Notes 1 Okay. Don’t worry! The fire is actually good