Human Reproduction — BIOLOGY STD 12 Science — Question

Alien species invasion has been a threat to biodiversity. Justify with the help of a suitable example. List any other three causes responsible for such a loss.

Your school has been selected by the Department of Education to organise and host an interschool seminar on 'Reproductive Health-Problems and Practices'. However, many parents are reluctant to permit their wards to attend it. Their argument is that the topic is 'too embarrassing'. Put forth four arguments with appropriate reasons and explanations to justify the topic to be very essential and timely.

Refer to the diagram given below and answer the questions that follow.

1. The parasite reproduces in human host by which method?
2. The sexual stages of parasite are referred to as?
3. Where does the fertilisation and development of parasite takes place in mosquito body?
4. What are sporozoites?
5. What is the cause of cycles of fever during malaria?

Mention the role of the following in E.coli cloning vector pBR 322.

1. Selectable marker.
2. ori.
3. rop.

1. What are the transcriptional products of RNApolymerase III?
2. Differentiate between 'Capping' and 'Tailing'.
3. Expand hnRNA.

A factory drains its waste water into the nearby lake. It has caused algal bloom.
How was the algal bloom caused?

This image highlights the process of Gene Therapy of ADA-SCID.

i. Mention the cause of ADA deficiency in humans.
ii. How has genetic engineering helped patients suffering from it?

What do you understand by Snow-blindness?

Define pollination. Explain any two contrivances of self-pollination.

List any four major categories into which contraception methods could be broadly classified. Explain briefly each category giving one example of each.