Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

There are certain complexities in eukaryotic transcription. Bring out the significance of such complexities.

While creation and presence of variation are directionless, natural selection is directional as it is in the context of adaptation. Comment.

Anita was happy when she gave birth to her first child. Her in-laws were dissatisfied at her not giving birth to a male child and blamed Anita. Anita tried to convince her in-laws that she had no role in the child's gender. They understood the biological reason but were yet to be satisfied. Anita's husband took up the matter and convinced the parents.
i. What values did Anita's husband show in the above situation?
ii. What governs sex determination in humans? How is it different from birds?
iii. Why can't Anita be blamed for not giving birth to a male child?

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

Rahul introduced Ronit to his uncle and told him that Ronit is pursuing a course in biotechnology in America.
His uncle had never heard of this term earlier and was curious to know about this term. Ronit pointed towards a big tree at the base of which were present numerous tumour-like structures and said that this is the example of natural biotechnology:

1. What is biotechnology?
2. How these crown gall tumours are formed?
3. What are the values shown by Rahul's uncle?

What does the term genetic diversity refer to? What is the significance of large genetic diversity in a population?

Describe Structure of typical angiospermic seed.

Describe the mammary gland by drawing well labelled diagram of sectional view and explain the mechanism of lactation.

Which layer of uterus undergoes cyclic changes during the menstrual cycle?