Some different tissuesEdit
These are found in many different animals, including humans. It is like animal cells, it contains the same things, but one difference is that it has many nuclei rather than one nucleus. They look stripy, this is because they are made up of many strands of protein arranged in a pattern. The strands of protein can slide between each other, making the cell much shorter. This is how the muscles contract.
These cells are found lining the trachea, oviduct and bronchi. Cilia are tiny extensions to the cell, which are covered with a cell surface membrane. Cilia move together in a rhythmic way, like a field of grass. These help to sweep fluids along the tube: in the trachea they help sweep mucus up to the throat.
Root hair cellsEdit
Are found in the roots, stems and leaves of plants (in a leaves they are in the veins). Xylem Vessels are made up of many long thin cells called elements, whcih are arranged end to end. These cells are unusual because they are dead. Their walls contain a very hard strong substance called lignin. Wood is made of xylem vessels which is why it is so strong. All that xylem vessels contain is water - one of their functions is to carry water to carry water from the roots up through the stem to the leaves and flowers. - this is part of the transpiration stream. Their other function is to support the plant.
Red blood cellsEdit
These are smaller than most other cells in humans, and have a cell surface membrane and a cytoplasm, however they don't have a nucleus. Their cytoplasm is full of red proteins called haemoglobin, which carries the oxygen from the lungs to other parts of your body. These cells are so small that they can squeeze through tiny blood vessels called capillaries: this enables them to take oxygen to almost every cell in your body. They are circular with a dent in the middle which gives them a large surface area for their size. This means that the oxygen can diffuse faster in and out of the cell.