ISC (Science) ISC Class 12 - CISCE Important Questions

Define Apomixis.

Type of Interaction where an individual sacrifices its own welfare (life) for the benefit of another animal of its own species is ______.

State four features of flowers pollinated by insects.

Explain the different types of endosperms in angiosperms. 

Give four adaptations shown by flowers pollinated by wind.

Briefly discuss any two methods by which plants avoid self-pollination.

The diagram given below shows the three types of endosperms in angiosperms.

Type 1	Type 2	Type 3

1. Identify the three types of endosperms shown above.
2. Name the type of endosperm which commonly occurs in polypetalous dicots.

The diagram given below is the L.S. of a typical fruit.

1. Identify the parts labelled '1', '2' and '3'.
2. State the difference between a true fruit and a false fruit.
3. What is the significance of the formation of fruit in angiosperms?

The number of chromosomes in the leaf cells of a male plant is 40 and in the stem cells of a female plant is 60. If they are artificially hybridised, what will be the number of chromosomes in the endosperm?

What is the advantage of growing apomictic seeds in crop improvement?

Name the pollinating agent of a flowering plant with large and coloured flowers with sticky stigma. State one characteristic feature of the pollen grains produced in such flowers.

Mention one significant difference between Hormones of ovulatory phase and hormones of luteal phase

Give reasons for the following:

Testes descend into the scrotum before birth.

Give a significant point of difference between the oestrous and menstrual cycles.

Draw a labelled diagram of L.S. of human testis.

Define Reproductive health

Define Amenorrhea

Briefly describe the secretory phase of the menstrual cycle.

Define: Menarche

Explain the role of hormones during the menstrual cycle.