Organisms and Populations — BIOLOGY STD 12 Science — Question

Write three differences between DNA and RNA.

What are sacred groves? What is their role in conservation?

A patient complains of suffering from constipation, stomach ache, stool with blood clots and excess mucous.
The physician diagnosed it as amoebiasis, after stool test.
a. Write the scientific name of the microbe identified in the stool sample.
b. How do you think, the patient must have contracted it?
c. Write your suggestions to the patient to avoid infection in future.

A large number of married couples the world over are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.
State any two reasons responsible for the cause of infertility.

Describe the structure of a seminiferous tubule.

What is community health? Write any seven important functions performed by community health centres.

Some parents wrote a complaint letter to the local municipality to remove all the hoardings in the city, advertising the use of condoms and matters relating to AIDS prevention. The children of these parents came to know about the matter and raised their voice against removal of the hoardings. The parents were convinced by the awareness level of their children and withdrew the complaint.

1. Parents considered the hoarding as inappropriate. Do you agree/ disagree with their view?
2. What are the methods by which AIDS spreads?
3. What is AIDS?
4. What values are promoted by the children protesting against their parents?

Draw a labelled diagram of female reproductive system.

A plant with red flowers was crossed with another plant with yellow flowers. If F₁ showed all flowers orange in colour, explain the inheritance.

When a cross in made between tall plant with yellow seeds (TtYy) and tall plant with green seed (Ttyy), what proportions of phenotype in the offspring could be expected to be,

1. Tall and green.
2. Dwarf and green.