Origin and Evolution of Life — BIOLOGY STD 12 Science — Question

Your school’s athletic team along with the athletic teams from different schools reach the venue two days before the inter district school athletic event was to be held. A day before the competition, a team of officials from an agency arrive and ask for blood and urine samples from all the participating athletes.

1. Would you support or object to this sample collection? Provide explanation to your answer.
2. Write a note that you would like to read out to your team-mates to explain the purpose of this visit of these officials.

State the Mendelian principle which can be derived from such a cross and not from monohybrid cross.

1. Explain the role of regulatory gene, operator, promoter and structural genes in lac operon, when E.coli is growing in a culture medium with the source of energy as lactose.
2. Mention what would happen, if lactose is withdrawn from the culture medium.

OR
Describe how the lac operon operates both in the presence and absence of an inducer in E.coli.

Unless the vector and source DNAs are cut, fragments separated and joined, the desired recombinant vector molecules cannot be created.

1. How are the desired DNA sequences cut?
2. Explain the technique used to separate the cut fragments.
3. How are the resultant fragments joined to the vector molecule?

Parasympathetic nervous system.

Following is the sequence of nucleotide in two strands of DNA. Observe the strands and answer the preceding questions.

1. Name the special term used for such an arrangement of nucleotide.
2. Name the special type of enzymes which work/ function at this specific points.
3. Name the enzyme, that cut DNA between GA sequence.
4. Name the single strands produced after the action of the enzyme.

Explain the different steps in the construction of recombinant DNA.

What essential features must be present in a cloning vector?

Vestigial organ.

Write notes on ex-situ conservation of biodiversity