Animal Cell
A typical animal cell is made up of :
- cytoplasm
- a nucleus
- a cell membrane
- vacuoles
Vacuoles are small cavities inside the cell which play a role in digestion inside the cell.
Cytoplasm is a jelly like substance that is found in all cells.It allows substances food and oxygen to be transported around the cell.
Nucleus is found in the cytoplasm.It is a very important part of the cell.There are thread-like structures in the nucleus.They contain information on how the cell should function.
Cell membrane is a soft and thin layer that surrounds the cytoplasm.This membrane holds the cytoplasm inside it.It also controls the substances that go into or out of the cell.
Plant cell
A typical plant cell is made up of :
- cytoplasm
- a nucleus
- a cell membrane
- a vacuole
- chloroplasts
- a cell wall
Vacuole is found in the centre of most plant cell.It contains the cell sap, which is a liquid that keeps the plant cell firm.Firm cells help plants to stand upright as plants do not have a skeleton system to provide system.
Cytoplasm is a jelly like substance that is found in all cells.It allows substances food and oxygen to be transported around the cell.
Cell wall is the outermost layer of a plant cell.It is made up of a stiff material that gives the plant cell its shape.
Nucleus is found in the cytoplasm.It is a very important part of the cell.There are thread-like structures in the nucleus.They contain information on how the cell should function.
Cell membrane is a soft and thin layer that surrounds the cytoplasm.This membrane holds the cytoplasm inside it.It also controls the substances that go into or out of the cell.
Chloroplasts are tiny green structures that can be found in the cytoplasm of a plant cell.Chloroplasts contain chlorophyll, the green pigment that traps sunlight to make food for the plant.
Cell division
Like all organisms, cell grow. As cells grow, they multiply.
Cells also multiply to replace the old cells that die.This process takes place in organisms all the time.
Multicelluar organisms
Human beings
As we grow, our body increases in size.This is because the number of cells in our body increases. Our body cells multiply by a process known as cell division.
Cells multiply by dividing themselves.The nucleus and cytoplasm of one cell divide to produce two cells. the new cells produced are identical to the original cell.
The process can be repeated .The two new cells can later divide to form four cells.
The cells in our body do not live forever.Our skin cells can live up to three weeks, while cells lining our intestines are replaced by new cells every three days.Some cells also divide to help repair damaged parts of our body.
http://www.youtube.com/watch?v=FKUc71E_xsw
Unicelluar organisms
Unicelluar organisms also multiply by dividing themselves.Since each unicelluar organism is made up of only one cell,a new organism is produced when a cell divides.
Bacteria and Paramecia
Unicelluar organisms, such as bacteria and paramecia, multiply by dividing themselves.
Yeast
Yeast mulitiplies by a special method of cell division called budding.During the process of budding, a small bud grows from a yeast cell.The bud then increases in size and breaks away from the original yeast cell.
From Cells To Organism
Human Beings
All the organs in our body are made up of cells.Let us see how cells form an organism such as the human being.
cell = tissue = organ = system = organism
In multicelluar organisms, cell are grouped together to carry out a particular function is called a tissue.
A type of tissue found in our body is muscle tissue, which is formed by a group of muscle cells.
An organ is formed when different tissues combine to perform a collective function.
An important organ in our body is the heart.It has muscle tissue, nerve tissue and connective tissue. All these tissues help the heart carry out its function of pumping blood to all cells in our body.
A system in our body is formed when several organs work together to perform a function.
For example our nervous system of our body is made up of the brain, spinal cord and other organs.
Our body is made up of many systems working together.
Plants
Plants are organised like human beings.They have cells, tissues, organs and systems.However, there are only two systems in plants - the shoot system and the root system.
Let us see how cells form an organism such as the plant.
cell=tissue=organ=system=organism
Energy in cells
An organism needs energy because its cells need energy to grow and divide themselves. Let us see how a cell gets energy.
http://www.youtube.com/watch?v=i8c5JcnFaJ0
The amount of energy a cell needs depends on its function.A muscle needs more energy than a hair cell as a muscle cell needs to repair itself from wear and tear more often.This is because we use our muscles daily.
The cells in our body do not live forever.Our skin cells can live up to three weeks, while cells lining our intestines are replaced by new cells every three days.Some cells also divide to help repair damaged parts of our body.
http://www.youtube.com/watch?v=FKUc71E_xsw
Unicelluar organismsUnicelluar organisms also multiply by dividing themselves.Since each unicelluar organism is made up of only one cell,a new organism is produced when a cell divides.
Bacteria and Paramecia
Unicelluar organisms, such as bacteria and paramecia, multiply by dividing themselves.
YeastYeast mulitiplies by a special method of cell division called budding.During the process of budding, a small bud grows from a yeast cell.The bud then increases in size and breaks away from the original yeast cell.
From Cells To Organism
Human Beings
All the organs in our body are made up of cells.Let us see how cells form an organism such as the human being.
cell = tissue = organ = system = organism- Cells to tissue
In multicelluar organisms, cell are grouped together to carry out a particular function is called a tissue.
A type of tissue found in our body is muscle tissue, which is formed by a group of muscle cells.
- Tissue to organ
An organ is formed when different tissues combine to perform a collective function.
An important organ in our body is the heart.It has muscle tissue, nerve tissue and connective tissue. All these tissues help the heart carry out its function of pumping blood to all cells in our body.
- Organs to system
A system in our body is formed when several organs work together to perform a function.
For example our nervous system of our body is made up of the brain, spinal cord and other organs.
- System to organism
Our body is made up of many systems working together.
Plants
Plants are organised like human beings.They have cells, tissues, organs and systems.However, there are only two systems in plants - the shoot system and the root system.
Let us see how cells form an organism such as the plant.
cell=tissue=organ=system=organism
- Cells to tissue
- Tissues to system
- Systems to organism
2.
- Cells to tissue
- Tissues to organ
- Organs to system
- Systems to organism
Energy in cellsAn organism needs energy because its cells need energy to grow and divide themselves. Let us see how a cell gets energy.
- Nutrients enter the cell through the cell membrane.
- The cell converts the nutrient into energy.Oxygen is needed for this process known as respiration.This energy is used by the cell to cell division, growth and repair.
http://www.youtube.com/watch?v=i8c5JcnFaJ0
The amount of energy a cell needs depends on its function.A muscle needs more energy than a hair cell as a muscle cell needs to repair itself from wear and tear more often.This is because we use our muscles daily.
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