ISC (Science) ISC Class 12 - CISCE Important Questions for Biology (Theory)

Define Amenorrhea

Briefly describe the secretory phase of the menstrual cycle.

Define: Menarche

Explain the role of hormones during the menstrual cycle.

Mention the location and the function of Leydig cells.

Given below is the diagram depicting the menstrual cycle in human beings. Study it carefully and answer the questions that follow.

1. Which phases are indicated by ‘C’ and ‘D’?
2. Name the structures labelled ‘F’. What is its role?
3. Explain the changes in the level of progesterone during phases ‘C’ and ‘D’.
4. Which hormone present in the urine confirms pregnancy in human beings?
5. Identify the structure labelled ‘E’. Name the hormone released by it.

Give a reason for the following:

The second half of the menstrual cycle is called the luteal phase as well as the secretory phase.

The diagram given below shows the various steps in spermatogenesis.

1. Name the parts labelled '1', '2' and '3'.
2. Name the process by which part '3' changes to part '4'.

Expand the STD

Write a brief note on the causes of infertility.

Give four causes of infertility in males.

Expand the following abbreviation MTP.

Expand the following abbreviation:

HIV

Define amniocentesis.

Differentiate between the following:

Spermatogenesis and oogenesis

Expand the following abbreviation:

IUCD

Mention the causative agent and the preventive measures for the following: Gonorrhoea

Give the role of amniocentesis.

Name the causative agent of gonorrhea.

Write the long form of GIFT.