Class 12 Biology – Ten Most Important Questions

Class 12 Important Biology Questions

In this article we will provide you ten important Biology questions, which will help you in your class 12 board exams and other entrance exams. Class 12 Important Biology Questions

Class 12 Important Biology Questions is very important resource for students preparing for Class XII board Examination. Question from very important topics are covered here for NCERT Class 12. You will also get idea about the type of questions, you can expect in your Class 12th examination.

Here you can get Class 12 Important Biology Questions based on NCERT Text book for Class XII. Here we have covered Important Questions on all topics for Class 12 Biology subject.

Class 12 Important Biology Questions

1. Plenty of algal bloom is observed in a pond in your locality. (a) Write what has caused this bloom and how does it affect the quality of water. (b) Suggest a preventive measure

2. In a flowering plant a microspore mother cell produces four male gametophytes while a megapore mother cell forms only one female gametophyte. Explain.

3. During a medical investigation, an infant was found to possess an extra chromosome-21. Describe the symptoms the child is likely to develop later in the life

4. ‘In-situ’ Conservation can help endangered/threatened species. Justify the statement.


Name and describe any three causes of bio-diversity losses

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

6. Our government has intentionally imposed strict conditions for M.T.P. in our country. Justify giving a reason.

7. A group of youth were having a ‘rave party’ in an isolated area and was raided by police. Packets of ‘smack’ and syringes with needles were found littered around.

(a) Why is taking ‘smack’ considered an abuse?

(b) Write the chemical name of ‘smack’ and the name of its source plant.

(c) Syringes and needles used by the youth for taking the drug could prove to be very fatal. Why?

8. Read the statement and answer the questions that follow.

A flower of brinjal has 520 ovules in its ovary. However, it produces a fruit with only 480 viable seeds.

(a) What could have prevented the rest of the 40 ovules from maturing into viable seeds? Explain giving a reason.

(b) Describe the development of a dicot embryo in a viable seed.

(c) Why certain angiospermic seed albuminous while others are exalbuminous? Explain.


(a) Name the hormones secreted and write their functions: (i) by corpus luteum and placenta (any two). (ii) during Follicular phase and parturition.

(b) Name the stages in a human female where: (i) Corpus luteum and placenta co-exist. (ii) Corpus luteum temporarily ceases to exist.

9. State and explain the “law of independent assortment” in a typical Mendelian dihybrid cross.


(a) How do the observations made during moth collection in pre- and postindustrialized era in England support evolution by Natural Selection?

(b) Explain the phenomenon that is well represented by Darwin’s finches other than natural selection.

10. Describe how do ‘flocs’ and ‘activated sludge’ help in Sewage Treatment.

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