Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Explain human female reproductive system.

Classify the following as examples of homology and analogy:

(i)	Mouth parts of cockroach and butterfly
(ii)	Hearts of rabbits and human beings
(iii)	Eyes of octopus and mammals
(iv)	Sweet potato and potato
(v)	Stings of honey bee and scorpion
(vi)	Tendrils of Lathyrus and tendrils of Gloriosa

Differentiate between vaccination and immunisation. Describe the two types of vaccines with suitable examples?

Following the collision of two trains, a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modem scientific method and write the procedure that would help in the identification of kinship.

1. Name the stage of Plasmodium that gains entry into the human body.
2. Trace the stages of Plasmodium in the body of female Anopheles after its entry.
3. Explain the cause of periodic recurrence of chill and high fever during malarial attack in humans.

State where the signals for parturition arise from, in humans.

1. It is generally observed that the children who had suffered from chicken - pox in their childhood may not contract the same disease in their adulthood. Explain giving reasons the basis of such an immunity in an individual. Name this kind of immunity.
2. What are interferons? Mention their role.

1. Name the causative agent of typhoid in humans.
2. Name the test administered to confirm the disease.
3. How does the pathogen gain entry into the human body? Write the diagnostic symptoms and mention the body organ that gets affected in severe cases.

Explain the primary productivity of ecosystem.

Study the graph given below and answer the question that follow:

1. Write the status of food and space in the curves (a) and (b).
2. In the absence of predators, which one of the two curves would appropriately depict the prey population?
3. Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.