Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Name the process of the rupture of Graafian follicle and the subsequent release of the egg from the ovary.

What is the study of fossils called? Mention any three points how the fossils throw light on the past.

Many secondary metabolites of plants have medicinal properties. It is their misuse that creates problems. Justify the statement with an example.

What do you understand by co-dominance? Explain the co-dominance by taking example of blood group in human.

Identify 'a', 'b', 'c', 'd', 'e' and 'f' in the table given below:

No.	Syndrome	Cause	Characteristics of affected individual	Sex Male/Female/Both
1	Down’s	Trisomy of 21	‘a’ (i) (ii)	'b'
2	‘c’	XXY	Overall masculine development	‘d’
3	Turner’s	45 with OX	‘e’ (i) (ii)	‘f’

Where is an 'operator' located in a prokaryote DNA? How does an operator regulate gene expression at transcriptional level in a prokaryote? Explain.

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

1. A tRNA is charged with the amino acid methionine.

1. Name the process involved in the attachment.
2. Point out the mRNA codon and anticodon on RNA for this amino acid.

2. What is heterochromatin?

What changes are seen in human male and females by onsetting of puberty.