|
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. |
y B��y0� ��� and T-lymphocytes.
4
It does not have a specific memory.
4
It is characterized by an immunological memory.
(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. |
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________.