Reproductive Health — BIOLOGY STD 12 Science — Question

Enlist the probable causes of infertility.

Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20 mg/L, 8 mg/L and 400 mg/L respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

Classify the following as examples of homology and analogy:

1. Mouth parts of cockroach and butterfly.
2. Hearts of rabbits and human beings.
3. Eyes of octopus and mammals.
4. Sweet potato and potato.
5. Stings of honeybee and scorpion.
6. Tendrils of Lathyrus and tendrils of Gloriosa.

Egrets are often seen along with grazing cattle. How do you refer to this interaction? Give a reason for this association.

What are the measures one has to take to prevent from contracting STDs?

Mark the odd one the following groups.
Fimbriae, Labia minora, Infundibulum, Isthmus.

1. How does the Hardy - Weinbergís expression (p2 + 2pq+ q2 = 1) explain that genetic equilibrium is maintained in a population.
2. List any two factors that can disturb the genetic equilibrium.

Describe sex-determination in birds with example.

Briefly describe industrial Melanism?

The sacred groves of Aravalli Hills and Ooty botanical garden, both aim at biodiversity conservation. How do they differ in their approaches? Explain.