CBSE Class 11 Biology - 3 Marks Important Questions


Some important three marks biology questions are given here for the CBSE class 11 exam. These questions are from the different biology chapters in the CBSE class 11 syllabus. Students can also visit CBSE question papers for class 11 biology to get various biology question papers of class 11 exam.

Before checking the questions, check some of the important points related to 3 marks questions.

  1. Six questions are included in the short answer- II section (3 marks questions).
  2. One internal choice is given in 1 question of this section.
  3. Step marking is necessary so; it is suggested to write answers properly in steps along with labelled diagrams.
  4. It is advised to write the answer in 3-4 lines only.

Important 3 Marks Questions For CBSE Class 11 Biology Exam

Question 1:

Who proposed the fluid mosaic model of plasma membrane? Draw its structure and write any two functions of it.

Question 2:

Write a short note on neural tissue.

Question 3:

Differentiate between Eutheria and Metatheria.

Question 4:

Name a gaseous plant hormone regulating its growth and other physiological functions. Describe some of its commercial uses in agriculture nowadays.

Question 5:

What is photorespiration and where does it take place?

Question 6:

What is the fluid mosaic model of the plasma membrane? Explain briefly.

Question 7:

Explain the structure of contractile proteins.

Question 8:

What do you mean by cofactors of an enzyme? What is the difference between the prosthetic group and coenzyme?

Question 9:

Write a short note on the action spectrum.

Question 10:

What is the significance of mitosis?

Question 11:

‘Bryophytes are referred to as amphibians of plant kingdom’. Justify.

Question 12:


(i) Chl-a and Chl-b

(ii) Photosystem-1 and II

Question 13:

Write a note on the different types of arrangement of vascular bundles.

Question 14:

Why is our heart called myogenic? What do the P-wave and T-wave represent in the

electrograph (ECG)?

Question 15:

Explain the mechanism of blood-clotting.

Question 16:

Draw a labelled diagram of a frog’s digestive system.

Question 17:

Write a note on the role of lysosomes in cellular metabolism.

Question 18:

State and briefly explain any three factors that regulate glomerular filtration rate.

Question 19:

Explain the kind of interactions between water molecules, that are responsible for the upward movement of water up to great heights in plants.

Question 20:

Write a short note on the action spectrum.

Question 21:

Compare the characters of Chordates and Non- Chordates.

Question 22:

Explain heterospory with two examples. What is its significance?

Question 23:

What is the role of calcium ions in muscle contraction?

Question 24:

What is guttation? Differentiate between guttation and transpiration.

Question 25:

Distinguish anaphase of mitosis from anaphase-1 of meiosis.

Question 26: 

What is double fertilization?


What is the difference between Angiosperms and Gymnosperms?

Question 28:

What are the symptoms of Growth Hormone Deficiency in humans?

Question 29:

What are the differences between monocotyledons and dicotyledons?

Question 30:

What are locomotion and movement?

Apart from these questions, students are advised to visit important questions for class 11 biology to check various chapter-wise important biology questions for class 11 exam. It should be noted that these questions are not only important for class 11 exam but are also crucial for the NEET exam.

For more assistance on class 11 biology preparation, stay tuned with BYJU’S.



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