PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -1-
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.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -2-
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…
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -3-
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.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -4-
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)
PSUB | Cycles | Notes 1
-5- © JustEdu Holdings Pte Ltd
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.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -6-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -7-
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!
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -8-
Do drop by our centre to view the full set of materials.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -9-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -10-
Do drop by our centre to view the full set of materials.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -11-
Do drop by our centre to view the full set of materials.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -12-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -13-
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
PSUB | Cycles | Notes 1
-14- © JustEdu Holdings Pte Ltd
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -15-
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!
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -16-
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_____________.
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -1-
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:
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -2-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -3-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -4-
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
PSUB | Cycles | Notes 1
© JustEdu Holdings Pte Ltd -5-
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)
-1- © JustEdu Holdings Pte Ltd
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)
© JustEdu Holdings Pte Ltd -2-
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