Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

Biodiversity plays a key role in many ecosystem services provided by nature.
(a) Present any two widely useful arguments to prove the validity of the statement.
(b) Write any one moral reason for protecting biodiversity.

Explain the following two components of Darwin's theory of natural selection.

1. Variations.
2. Formation of new species.

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

Differentiate between an annual and a biennial plant. Provide one example of each.

How do antibiotic-resistance genes function as selectable markers? Explain with the help of E.coli cloning vector pBR 322.

Explain pyramid of numbers with the help of an example.

Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.

1. Name the ailments the two girls were suffering from?
2. Why did the treatment provided to girl A required repeated visits?
3. How was the girl B cured permanently?

1. Identify the polarity at A and B respectively in the figure given below.
2. Explain the mechanism the figure represents.

A population of Paramoecium caudatum was grown in a culture medium. After 5 days the culture medium became overcrowed with Paramoeium and had depleted nutrients. What will happen to the population and what type of growth curve will the population attain? Draw the growth curve.

Differentiate between monosomy and trisomy. Give an example of each from human geneties.