Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

1. List the three different allelic forms of gene ‘I’ in humans. Explain the different phenotypic expressions, controlled by these three forms.
2.  A woman with blood group'A'marries a man with blood group 'O'. Discuss the possibilities of the inheritance of the blood groups in the following, starting with 'yes' or 'no' for each:

1. They produce children with blood group ‘A’ only.
2. They produce children, some with 'O' blood group and some with 'A' blood group.

Answer the following questions:
Draw a labelled diagram of a sectional view of human seminiferous tubule.

In 1952, Alfred Hershey and Martha Chase took an effort to find the genetic material in organisms. Their experiments led to an unequivocal proof to DNA as genetic material.


Answer the following questions based on Hershey and Chases's experiments:
i. Name the kind of virus they worked with and why?
ii. Why did they use two types of culture media to grow viruses in? Explain.
iii. What was the need for using a blender and later a centrifuge during their experiments? OR
iv. State the conclusion drawn by them after the experiments.

What is endosperm of angiosperms ? Describe its types.###What is endosperm ? Explain various types of endosperms.

Name the modern technology of crop improvement. How is it beneficial in crop improvement? Explain. ###Write an essay on tissue culture.

Give a schematic labelled diagram to represent oögenesis (without descriptions)

Define an operon. Giving an example, explain an Inducible operon.

What is an ecosystem service? List any four important ecosystem services provided by the natural ecosystems. Are you in favour or against levying a charge on the service provided by the ecosystem?

What is Biogas? Describe biogas plant with the help of diagrams.

It is commonly observed that parents feel embarrassed to discuss freely with their adolescent children about sexuality and reproduction. The result of this parental inhibition is that the children go astray sometimes.

1. Explain the reasons that you feel are behind such embarrassment amongst some parents to freely discuss such issues with their growing children.
2. By taking one example of a local plant and animal, how would you help these parents to overcome such inhibitions about reproduction and sexuality?