Question 12
How is a cancerous cell different from a normal cell?
| Normal cell |
| Cancerous cell |
1. | Normal cells show the property of contact inhibition. Therefore, when these cells come into contact with other cells, they stop dividing. | 1 | Cancerous cells lack the property of contact inhibition. Therefore, they continue to divide, thereby forming a mass of cells or tumor. |
2. | They undergo differentiation after attaining a specific growth. | 2. | They do not undergo differentiation. |
3. | These cells remain confined at a particular location. | 3 | These cells do not remain confined at a particular location. They move into neighboring tissues and disturb its function. |
(b) Active and passive immunity
| Active immunity |
| Passive immunity |
1. | It is a type of acquired immunity in which the body produces its own antibodies against disease-causing antigens. | 1. | It is a type of acquired immunity in which readymade antibodies are transferred from one individual to another. |
2. | It has a long lasting effect. | 2. | It does not have long lasting effect. |
3. | It is slow. It takes time in producing antibodies and giving responses. | 3. | It is fast. It provides immediate relief. |
4. | Injecting microbes through vaccination inside the body is an example of active immunity. | 4. | Transfer of antibodies present in the mother’s milk to the infant is an example of passive immunity. |