Download Primary Upper Block Cycles: Reproduction in Plants Introduction to

Primary Upper Block
Cycles: Reproduction in Plants
Introduction to Notes 1
The scouts have all gone to sleep in their tents after a
campfire but they did not put out the fire…
We know children like
Inside
a pine cone on the tree…
comics! Using that
to our
advantage, we introduce
complicated concepts in
a fun way.
Big brother,
The fire grew bigger and
closer to a pine tree.
Oh no! There is
a fire outside!
We are all going
to die!
why is it so
hot?
Don’t worry! The
fire is actually good
for us. Everyone, get
ready to leave the
cone!
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!
Little sister, don’t
open the parachute
first. You open it only
when you start to fall
downwards.
OOPS!
Okay.
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It’s almost time now.
Everyone, please get into
your positions!
Take care!
Bye, big
brother!
BOOM
The seeds left the cone and began their journeys…
Where are
the rest?
Where am
I?
I’m
falling!
A
few
years
later, the little
seed has grown
into a new pine
tree…
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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.
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
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Primary Upper Block
Cycles: Reproduction in Plants
Notes 1
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.
Plant Reproduction
Asexual Reproduction
Sexual Reproduction
seeds
without the help of Man
spores
natural vegetative
reproduction
(from other plant parts)
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with the help of Man
artificial vegetative
propagation
PSUB | Cycles | Notes 1
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SEXUAL REPRODUCTION IN FLOWERING PLANTS
Visuals help our students to

In sexual
reproduction,
male and female parts of the plant are involved in producing a new plant.
grasp
the conceptsthe
quickly.

The new plant is not identical to the parent plant.
PARTS OF A FLOWER

The flowers of flowering plants contain the parts for reproduction.
STAMEN
male part
of the flower
STIGMA
Pollen grains are received here.
ANTHER
- It contains four pollen sacs.
- Each pollen sac carries many
male reproductive cells (pollen
or pollen grains).
STYLE
connects the stigma to the ovary
PISTIL
female part
of the flower
FILAMENT
to hold the anther out
OVARY (grows into a fruit)
OVULE (grows into a seed)
Each ovule carries a female
reproductive cell (egg).
SEPAL
protects the flower
FLOWER STALK
PSUB | Cycles | Notes 1
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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
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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!
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Do drop by our centre
to view the full set of
materials.
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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
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Do drop by our centre
to view the full set of
materials.
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Do drop by our centre
to view the full set of
materials.
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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) African tulip
kapok
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CASE STUDY H
PROCESS OF GERMINATION
1
2
The root emerges
from the seed
coat and grows
downwards.
first root
shoot
The shoot then
emerges and grows
upward out of the
soil. The seed coat
may fall off.
3
seed coat
first leaves
4
first leaves
The shoot grows taller
and the first leaves
start to develop. The
roots also grow longer.
seed leaves
The first leaves spread
out. They start to make
food (or photosynthesise)
for the plant. The seed
leaves eventually fall off.
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PSUB | Cycles | Notes 1
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LIFE CYCLE OF A FLOWERING PLANT
dispersal of fruits
and seeds
sufficient warmth, oxygen
and water are present
seed lands on
fertile soil
root emerges
pollination and
fertilisation occur
plant matures and
produces flowers
first shoot emerges and
grows out of soil
first leaves emerge
young plant
continues to grow
first leaves spread out and start
to photosynthesise, seed
leaves wither and fall off
PSUB | Cycles | Notes 1
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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.
Summarising the chapter
helps our students to recap
what has been taught during
the lesson!
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.
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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
c_______________
pollinated
flowers
by
animals
or
flowers
usually
which
have
are
b_______________
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_____________.
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Primary Upper Block
Cycles: Reproduction in Plants
Practice 1
Our notes are complemented
by a comprehensive Practice
paper.
A typical practice will have 15 multiplechoice 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:
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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.
pollen grains
pollen grains
Flower A
Flower B
(a) Which flower is more likely to develop into a fruit? (1m)
(b) Explain your answer to (a). (2m)
STEP 1: ANALYSE THE QUESTION
Circle the important information in the question. Study the diagram and write down in
the space below the information that you can obtain.
STEP 2: CONCEPT ANCHORING
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.
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
The ovary will develop into a __________________ upon fertilisation of the
ovules.
(b) Key points: ______________________________________________________
______________________________________________________
STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES
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)
________________________________________________________________
________________________________________________________________
________________________________________________________________
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PSUB | Cycles | Notes 1
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Answers
Use the ACE Question Answering Technique to answer the question below.
STEP 1: ANALYSE THE QUESTION
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.
pollen grains
pollen grains
Flower A
Flower B
(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
STEP 2: CONCEPT ANCHORING
Reproduction in plants
Topic: _____________________________________________________________
Concepts:

pollinated
A flower is successfully __________________
when pollen grains from the same
species
stigma
__________________
land on the __________________
of the flower.

pollen
A pollen tube is formed after pollination to transport the __________________
stigma
towards the ovary from the __________________.

fertilises
The pollen __________________
the ovule in the ovary.
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Answers

fruit
The ovary will develop into a __________________
upon fertilisation of the
ovules.
Pollination, pollen grain land on stigma,
(c) Key points: ______________________________________________________
pollen transported to ovary, fertilise ovule,
______________________________________________________
ovary develop into fruit.
______________________________________________________
STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES
Link the requirements in the question with all the keywords listed. You may use arrows
or a simple concept map to help you.
Flower B
Flower A
Pollen grain
Pollination
lands on stigma
does not occur
Pollination
occurs
Pollen tube grows to transport
pollen from stigma to ovary
Pollen fertilises ovule in ovary
Ovary develops into
fruit
Answers:
(a) Which flower is more likely to develop into a fruit? (1m)
Flower B
________________________________________________________________
(b) Explain your answer to (a). (2m)
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.
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PSUB | Cycles | Notes 1
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Primary Upper Block | Cycles: Reproduction in Plants | Concept Map
Underground stems
Reproduction of Plants
two parents needed
At the end of each topic,
students are equipped with
a concept map and a list ofSexual reproduction
Plants reproduce
to phrases to
keywords and
reinforce
the
ensure the continuitykey concepts
the kind.
topic.
of theirofown
potato, ginger
Underground roots
only one parent needed
carrot, turnip
Asexual reproduction
Suckers
By spores
banana, pineapple
By seeds
Sexual Reproduction in Flowering Plants
Female parts
1) stigma
1) anther
2) filament
Leaves
moss
bryophyllum, begonia
Sequence of events
Structure of a flower
Male parts
fern
2) style
with sufficient warmth, water and oxygen,
the seed will be able to germinate.
1. Pollination
2. Fertilisation
3. Seed dispersal
4. Germination
Pollen grains are
transferred by
wind or animals
from the anther
to the stigma.
Fertilisation
occurs when
the nucleus of
the pollen grain
enters the ovule
and fuses with
the egg to form
a fertilised egg.
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.
3) ovary
(develops into a fruit)
4) ovule (develops into a seed)
PSUB | Cycles | Concept Map (for student’s reference only)
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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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PSUB | Cycles | Concept Map (for student’s reference only)
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