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Science 7 - Coggle Diagram
Science 7
Cells
Cells are the building blocks of all organism and they make up all living organisms. They are extremely small and they require a microscope to look at them.
Plant cells have:
Cell walls, these are strong and stiff and it holds the cell in shape. Plant cell walls are made up of cellulose.
Cell membrane, all cells have a cell membrane. The cell membrane is very flexible and thin. It lies along the inner edge of the cell wall and it controls what goes in the out.
Cytoplasm, all cells have it and it is a clear jelly where chemical reactions happen inside of it. These reactions keep the cells alive.
Nucleus, most cell activities happen here and the nucleus controls the activities of the cells.
Sap Vacuole, this is a large fluid filled space in a plant cell. The fluid inside contains a lot of sugars and other substances dissolved in water. It is called cell sap.
Chloroplasts, these things help collect sunlight to help to make their food and it contains chlorophyll that absorbs sunlight.
Mitochondria, all plant cells have mitochondria and inside it energy is being realeased from food.
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Specialised cells
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Red blood cells are getting smaller than most other cells in the body. This allows then to get through capillaries to delver oxygen. They have a red pigment called haemoglobin and it helps with carrying the oxygen around the body. It has no nucleus and it leaves space for haemogoblin.
Neurons carry electrical signal to one part of the body to the other. They help with communication in the body. For example, they carry signal from the brain to muscle to help them move. The axon is a ver long strand from them and electrical signals can happen very quickly. Dendrites are short strands of cytoplasm that collect other electical signal.
Cilliated cells have tiny threads along one edge like microscopic hairs. These are called cilia and they can move, they lie in our respatory system. Other cells in this lining makes up mucus, When you breathe in, mucus straps dust and bacteri in the air to stop them from going into your lungs.
Root hair cells are cells found in the root. Their function is to absorb water from the soil. Each cell has a long to move easily from the soil to the cell.
Palisade cells are cells found in the leaf and their function is to make food by photosynthesis. That is why they have a great amount of cholroplasts that contains chlorophyll that absorbs energy from sunlight, which helps it make food.
Cells, tissue and organs
A group of simmilar cells working together to do a particular function is called a tissue. Examples are onion epidermis which covers the layers inside an onion and cialated epithelium.
An organ is a group of similar tissues wroking together. Like the brain, the liver and the lung.
A organ system is a system of organs that work together to carry out the same function. Like the respiratory system or the digestive system.
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