Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

Pollination, Fertilisation, Seed Dispersal, Germination and
Photosynthesis, Grade 8 Biology
Written By:- Maria Batool

Table of Content
5 Processes that take place in Plants
Processes in Plants:1
...
Fertilisation
After the Process of Fertilisation:
3
...
Germination
What are favourable conditions?
Seed Structure:
Seed coat:
Cotyledon:
Baby plant:
Let's go through the process of germination through steps:
5
...
In this lesson we will learn about 5 processes that take place in the plants
...
Pollination:
To understand, it is first important to understand:
What are Pollinators?
Pollinators are those insects or living organisms which help in the process of
pollination by transferring the pollen grains from the anther (male part) to the
stigma (female part)
...

Examples of Pollinators:
1
...
Human/People
3
...
When they fly off,
the pollen stuck to their body falls off onto the stigma of the flower
...
If the pollen falls on
to the stigma of another flower, this is called cross-pollination
...
Fertilisation
When the pollen falls on the stigma, the pollen develops a pollen tube that goes all
the way down, through the style, to the ovary and ovule inside it
...
When the
sperm cell, that was inside the pollen grain, reaches the ovule ( present inside the
ovary) the process of fertilisation starts
...
After the fusion,
zygote is formed
...

After the Process of Fertilisation:
Now, after the process of fertilisation has successfully taken place the ovary develops
into a fruit and ovule develops into seeds
...
The seeds
contain the embryo that will further develop into a big plant
...

Plants fertilisation process is called sexual reproduction, where male and female
gametes fuse together to form zygote
...


3
...
For the seeds to turn into a plant, the seed
goes through two processes:
1
...
Germination

Seed Dispersal:
Seed dispersal is the process in which seeds of a plant are transported to a place,
which is a considerable distance from the parent plant, by the agents
...
However, the seeds could fall
off near the parent plant
...
A-biotic agents: these are the agents which are non-living organisms
...
Biotic agents: these are the agents which are living things
...
Examples of agents are:
1
...
Water
3
...
Animals
Wind, water and explosion are a-biotic (these processes are those which do not
involve any living organisms) and animals are biotic agents (processes which
involve living organisms)
...


Seed dispersal through:
Wind:
Seeds like dandelion seeds, have a parachute or hair-like structure, which makes it
easier for the wind to carry them
...
When the wind stops, the dandelion seeds fall off
...


Water:
Fruits which can float, like coconut and lotus, are carried away by water and these
types of fruit travel farthest away from the parent plant
...
When a plant's fruit has properly ripened, a
point comes when the fruit is so fully grown that the fruit bursts open with a force
...
Examples of such fruit plants are broom and pea
plants
...
Recall, what do you do with the
seed of a juicy fruit after you eat the fruit? We throw it away
...

Birds also like seeds of juicy fruit
...
When the bird is not able to digest it, the seed
comes out of the bird in its waste
...
So
after the seed comes out with the waste, the seed easily goes into the soil and the
process of germination becomes relatively easier
...

But the question arises: why is the process of seed dispersal important for
plants?

Importance of Seed dispersal:
If the seeds grow near the parent plant, it will affect the growth and development of
both the parent plant and the baby plant
...
This will affect
both plants and the baby plant will not grow properly
...


4
...
After the seeds
are dispersed away from the parent plant, the process of germination starts
...


What are favourable conditions?
Favourable conditions for a plant growth are:
1
...
Maximum amount of water
3
...


Seed Structure:
Seed coat:
It is a protective layer around the seed
...

Baby plant:
It is the embryo, from which a new plant grows
...
When the seed is sown into the soil, the seed consumes water from the soil
rapidly, swelling and softening the seed coat
...

2
...

3
...

4
...


Finally we see the growing part (shoot) rising through the seed coat, when the seed
coat splits open to give rise to the seedling, and emerging above the ground for

sunlight
...
Once it is gone, the roots and leaves take over the task of supplying food to
the new plant, with the process of photosynthesis the single seed grows into a plant
...
Photosynthesis
Plants are natural beauty
...
They make their own
food! This process in which plants make their own food is known as
Photosynthesis
...


What does photosynthesis mean?
Photo is a Greek word which means light and synthesis, another Greek word means
making with
...
This process takes
place in the green parts of the plant, majorly in the leaves, in the palisade cells
present in the palisade mesophyll
...
Sunlight: (plants absorb sunlight with the help of chloroplasts)
2
...
Water: (roots absorb water and transport it to the leaves)

Process:Roots and Stem:
From the soil, roots absorb water and minerals and transport it to the stem
...
The stem holds the leaves in such a position that they absorb
maximum sunlight
...
The carbon dioxide
enters the leaves through the tiny opening called stomata
...
These materials are absorbed by the
chloroplast
...
Just like
humans have respiration systems, plants also d0
...

(absorbed from the surroundings)+(absorbed by the roots)-----(used by the
plants)+(released in the surroundings)
These products diffuse out of the cell containing chloroplast
...


Wrap Up of Photosynthesis:

In the process of photosynthesis, plants make their own food
...
This
process is very important for living beings as plants take in carbon dioxide and give
out oxygen which keeps the environment clean and fresh

---