Animal cells, plant cells, and unicellular organisms
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Explainer Video
Summary
Animal cells, plant cells, and unicellular organisms
In a nutshell
Cells are the building blocks of life. Unicellular organisms are made up of only one cell. Multicellular organisms, such as animals and plants, are made up of lots of cells. Animal cells and plant cells share many similarities and differences.
Animal cell
Animal cells have many different features. These are described below.
| 1. | Cytoplasm | The liquid component of the of the cell where most chemical reactions happen. |
| 2. | Nucleus | This controls what happens in the cell and contains the genetic material. |
| 3. | Mitochondria | Small structures where respiration takes place. Mitochondrion is the name given to one mitochondria. |
| 4. | Cell membrane | A supportive outer layer that controls which substances enter and leave the cell. |
Plant cell
Plant cells have many of the same features as animal cells but they also have a cell wall, chloroplasts and a vacuole.
| 1. | Nucleus | This controls what happens in the cell and contains the genetic material. |
| 2. | Cytoplasm | The liquid component of the of the cell where most chemical reactions happen. |
| 3. | Mitochondria | A small structure where respiration takes place. Mitochondrion is the name given to one mitochondria. |
| 4. | Chloroplast | Structures that contain a green pigment called chlorophyll. This is where photosynthesis happens. |
| 5. | Cell membrane | A supportive outer layer that controls which substances enter and leave the cell. |
| 6. | Cell wall | A stiff extra outer layer made from cellulose. This extra layer provides strength and supports the plant cell. |
| 7. | Vacuole | A sac that contains cell sap which contains salts and sugars. The vacuole keeps the plant cell rigid. |
Multicellular and unicellular organisms
Cells are the basic building blocks of all animals and plants. Multicellular organisms, such as humans and animals, are made up of lots of cells. Unicellular organisms, like bacteria, are made up of just one cell. Unicellular organisms usually have adaptations to help them to survive.
Euglena
Euglena are unicellular organisms that live in the water.
| 1. | Their genetic material is found in the nucleus. |
| 2. | They have chloroplasts that they can use for photosynthesis. |
| 3. | They have a flagellum which is a tail-like structure that rotates to help them swim. |
Amoeba
Amoeba are another example of unicellular organisms that can live in water.
| 1. | Their genetic material is found in the nucleus. |
| 2. | They have a contractile vacuole that collects any water that enters the cell. |
| 3. | They can contract (squeeze) it at the cell membrane to remove any water from the cell. |
FAQs - Frequently Asked Questions
What does the nucleus do?
The nucleus controls what happens in the cell and contains the genetic material.
What are chloroplasts?
Chloroplasts are structures that contain a green pigment called chlorophyll. This is where photosynthesis happens.
What is an example of unicellular organisms adapting to their environment?
Euglena are unicellular organisms that live in the water. They have a flagellum which is a tail-like structure that rotates to help them swim.
What is the difference between unicellular and multicellular organisms?
Unicellular organisms are made up of only one cell. Multicellular organisms, such as animals and plants, are made up of lots of cells.