Human Reproduction — BIOLOGY STD 12 Science — Question

Describe the functions of the following:
Vagina.

Draw a labelled schematic structure of a transcription unit. Explain the function of each component in the unit in the process of transcription.

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?

Why do some adolescents start taking drugs? How can the situation be avoided?

Draw a diagrammatic labelled sectional view of a seminiferous tubule of a human.

What is biogas? Explain its production with the help of a diagram.

Replication was allowed to take place in the presence of radioactive deoxynucleotides precursors in E.coli that was a mutant for DNA ligase. Newly synthesised radioactive DNA was purified and strands were separated by denaturation. These were centrifuged using density gradient centrifugation. Which of the following would be a correct result?

1. Name the nuclei that fuse to form PEN.
2. What is the ploidy of PEN?
3. Explain the development of endosperm from PEN?

What is called retrovirus? Show the replication of retrovirus with the help of diagram.

Explain the ovarian and uterine events that occur during a menstrual cycle in a human female, under the influence of Pituitary and Ovarian hormones respectively.