Consider statements about human immunity: 1. Active immunity involves the body producing its own antibodies. 2. Passive immunity involves receiving pre-formed antibodies. 3. Vaccination provides passive immunity. Which are correct? MCQ with Answer and Explanation
Consider statements about human immunity: 1. Active immunity involves the body producing its own antibodies. 2. Passive immunity involves receiving pre-formed antibodies. 3. Vaccination provides passive immunity. Which are correct?
A. 2 and 3 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2 and 3
Answer: Option B
Solution (By JKSSB Mock Tests)
Active immunity occurs when the body's own immune system is stimulated by an antigen (either through infection or vaccination) to produce its own antibodies and memory cells, providing long-lasting protection. Passive immunity occurs when an individual is directly given pre-formed antibodies (like through mother's milk or antiserum), providing immediate but temporary protection. Vaccination stimulates the body to produce its own immune response, thus providing artificial active immunity, not passive. Thus, statements 1 and 2 are correct.
Explanation:
The most unique and defining characteristic of Class Aves (birds) is the presence of feathers, which are modified scales used for flight and insulation. Birds are warm-blooded (homeothermic), have a four-chambered heart, and possess a beak instead of jaws. Mammary glands and external pinnae are features of mammals.
Explanation:
Dolly (1996) was created by somatic cell nuclear transfer (SCNT), where the nucleus from an adult somatic cell (udder) was transferred into an enucleated egg cell, which was then implanted in a surrogate. This proved that differentiated somatic cells can be reprogrammed to totipotency. She was the first mammal cloned from an adult cell.
Explanation:
Natural active immunity develops when a person is exposed to a live pathogen, develops an immune response, and creates memory cells. Artificial active is from vaccination. Passive immunity involves receiving antibodies.
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