Do all cells in our body look alike in terms of shape, size and structure ? Explain with the help of examples. What similarities do they have?
Answers
The human cell is the basic independent self-sufficient and functioning unit of a human body. We have more than a billion cells inside us. The cells do group together to make different organs. The basic structure of the cell is same. A cell contains the cell membrane or plasma membrane (outer boundary). Inside it there is a gelatinous jelly like fluid called Cytoplasm. Floating in it are many different parts called Organelles. Nucleus inside the cell is the brain of the cell. The DNA inside the cell uniquely identifies each of us.
There are about 200 different cell types which perform different functions. They contain different organelles. They have also different shapes and sizes. They are located in different parts.
In red blood cells most of these organelles are not present. It does not have a nucleus, mitochondria or endoplasmic reticulum. Ovum cell has Follicle cells and corona radiata outside their plasma membrane. It has a thicker plasma membrane. It does not have so many organelles floating inside cytoplasm. Neuron cell is elongated chain like shaped containing protrusions called dendrites and axon terminal on their ends. Some neuron cells are as long as some centimeters and more.
Similarly Intestine cells (on its inner surface) have a different shape. The bone cells too are different as you can see from the diagrams. The shape and the organelles in different types of human cells are meant for different functions. So different organs (containing different tissues of cells ) perform different functions.
Epithelial cells are simple cells. They are for just covering the other cells. Muscle cells contain a lot of proteins. Bone cells contain a lot of phosphates and Calcium. Adipose cells are the fat cells on the palms and under the feet. They reduce friction to the body.
All cells need Oxygen. They breathe. All cells have mitochondrion where Oxygen and parts of food give rise to energy. All cells divide themselves for growth and also repair of damaged cells.
