Human Health and Disease — BIOLOGY STD 12 Science — Question

Define acquired immunity and describe its types.

Differentiate between homology and analogy. Also discuss the homologous and vestigeal organs with example and how do they explain the evidence of evolution.

Why do some adolescents start taking drugs. How can this be avoided?

Compare the processes of DNA replication and transcription in prokaryotes.

Explain spermatogenesis.

1. Name the respective forms in which the malarial parasite gains entry into

1. Human body and
2. Body of female Anopheles.

2. Name the respective hosts and the sites in their body, where the sexual and asexual reproduction of malarial parasite occur.
3. What is meant by:

1. Addiction
2. Dependence with reference to drugs/ alcohol?

Answer the following questions:
Explain the events that occur in a graafian follicle at the time of ovulation and thereafter.

Differentiate between:

1. Predator and parasite.
2. S-Shaped and J-Shaped growth curve.

Give few examples of biofortified crops. What benefits do they offer to the society?

With the help of suitable diagram describe the logistic population growth curve.