Parts of an animal cell and their functions biology lesson for kids: 1st, 2nd, 3rd, 4th, 5th, 6th and 7th grades biology lesson.
Animal cells are like the cells of many kinds of other organisms in many ways. They have many of the same organelles that even organisms like fungi have. Still, there are some things that animal cells have that other kinds of cells like plant cells don’t have.
Almost every animal cell has a nucleus (plural: nuclei). This is where the DNA is kept, and DNA is important for telling the cell what to do. There is an important exception, though: mammal red blood cells have no nuclei. This allows the red blood cells to have more space for the protein that holds oxygen, so the blood can carry oxygen from the lungs all over the body. Humans are mammals, so our red blood cells don’t have nuclei.
Animal cells also have structures called centrioles. These are important for cell division, the process of cells splitting into smaller baby cells. Centrioles produce fibres called spindles and are kept in an organelle called the centrosome, which stays very close to the nucleus of the cell most of the time. When the cell is ready to divide, the nucleus membrane breaks apart and centrioles move to opposite ends of the cell. Then, the spindles pull the newly copied DNA apart, so every baby cell can have its own copy if the DNA. Although this is very important for animal cells, plant cells don’t have centrioles. They have another way to make spindles.
Another part of the animal cell that plant cells don’t have is called lysosomes. These are basically balls of enzymes that break up big molecules into smaller pieces. Lysosomes are basically the digestive system of the cell, and break down old parts that need replacing, or molecules that the cell takes in from around it. There are many different types of lysosomes, and they come in lots of different shapes and sizes.
Some animal cells also have cilia (singular: cilium) and flagella (singular: flagellum). Both of these are used for movement. Cilia and flagella are very similar, but cilia are smaller, and there are usually a lot more of them. Cilia are basically tiny hairs that the cell uses to paddle through the water. A flagellum is a tail that the cell uses to swim, kind of like a fish. If an animal cell needs to move, chances are, it has either cilia or a flagellum.
Apart from these, animal cells also have small vacuoles for storing food, mitochondria (singular: mitochondrion) for releasing energy from sugar, and ribosomes, which help the cell to carry out the instructions found in DNA.
All these and others worth together to make animal cells the amazing little biological machines that they are.