Cells and MRS GREN revision. The 7 signs of life. Animal and plant cells. Here is a picture of a plant cell and an animal cell. Cells are the smallest units of life. Some cells can exist on their own, whilst others are found in groups.
Here is a picture of a plant cell and an animal cell.
Cells are the smallest units of life.
Some cells can exist on their own, whilst others are found in groups.
Humans are a collection of many billions of cells, all working together.
While some cells do look different, all cells have three basic features.
Most cells have three basic parts.
But cells can be different shapes and sizes and also have different functions. This is because they are…
The shape of a cell is related to its function.
Where do you see this idea in sport?
CLUE: World Cup!
Why are the players in a rugby union team different shapes and sizes?
Rugby players are different shapes and sizes because they do different jobs for the team.
Like rugby players, cells are different shapes and sizes because they perform different jobs.
Vacuole (contains cell sap)
Chloroplast (contains chlorophyll)
Therefore, if plants and animals are different shapes, they must be made of different shaped cells. Let’s have a look at the shape of a basic plant cell.
Apart from the shape, the cell looks very similar to an animal cell.
However, here is how the plant cell differs from the animal cell.
Now that we know what the basic structure of a plant and animal cell is, we can begin looking at the bigger picture.
Cells are not flat…..
…they are usually three-dimensional
The 3D shape of the cell will be determined by its location in the body and the job it does.
You can make your own 3D cell using the following equipment.
You will need to find some small objects to suspend in the cellulose paste. These will represent the internal structures of the cell.
Try to make a model of both the plant and animal cell. Then label these and display them.
A great way to visualize how a cell functions, is to become one!
You can get people to stand in a circle, holding hands to represent a cell membrane.
Then, get other people to be the nucleus and so on. If you are feeling adventurous, you can even dress up to represent the job of that part of the cell.
Make sure you have a cell membrane and a nucleus as a minimum. Then you can choose from the list and role-play cell activity.
As we know, all life is built of cells. The way we look is the result of the types of cell we are made of and the way those cells are organised.
For example, if we look at the cells of the plant and animal, it is no surprise that plants and animals look different…
To help us understand this, think of how a school is organised.
A school needs to be very organised. Every pupil in the school needs to know where they should be and what they are doing. However...
Not all pupils study the same subjects.
Not all pupils can work together efficiently.
There is not room for all the pupils to be in the same place.
Therefore, a school uses the following system.
A year group
This hierarchy of organisation is also found in living organisms.
Each specific cell
Is grouped with cells similar in structure and function.
We call this a tissue.
Can you think of any more types of tissue?
Together, they are known as an….
ORGANHow is the body organised?
Q. Can you think of a problem if one cell splits to produce two cells?
A. The two new cells would be smaller than the original cell.
Therefore, a cell needs to make new copies of the material inside itself as well as the membrane and nucleus.
Just before a cell divides, it will appear to grow slightly as it reproduces everything inside itself.
The nucleus must also divide into two equal halves.
This only occurs once the nucleus has doubled from its original size.
Cell division occurs extremely quickly and can happen over and over again.
Produce an enormous number of reproductive cells.
Repair cuts and replace dead cells quickly.
This is how it is possible for the body to ...