Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

What is inheritance & variation?

Differentiate between : Repetitive DNA and Satellite DNA

Evidences that evolution of life forms has indeed taken place come from many quarters. Name any four branches of biology that support or provide evidence for organic evolution.

Is the use of contraceptives justified? Give reasons.

How do mycorrhizal fungi help the plants harbouring them?

Why is Agrobacterium tumifaciens a good cloning vector? Explain.

List the post-fertilisation events in angiosperms.

A new type of drug, PTC 124, enables translation to continue through the nonsense codon. Trials in mice homozygous for a CFTR allele containing the nonsense codon have found that animals treated with PTC 124 produce normal CFTR protein in their cells. The drug is taken orally and is readily taken up into cells all over the body.
Using your knowledge of the progress towards successful gene therapy for cystic fibrosis, suggest why PTC 124 could be simpler and more reliable treatment for this disease.

A mRNA strand has a series of codons out of which three are given below:

1. AUG
2. UUU
3. UAG

1. What will these DNA codons be translated into?
2. What are the DNA codons that would have transcribed these RNA codons?

'Introducing sex education in school is a good step for providing right information to adolescents'. In context to the statement given above, answer the questions that follow.

1. Which part of the brain controls the sex urge?
2. What are the necessary topics that should be taught in schools, in context of STDs and AIDS.