CBSE Class 12 Biology - 2 Marks Important Questions

CBSE class 12 students are provided with some important 2 marks questions here. The questions are designed according to the latest CBSE curriculum and updated pattern. These 2 marks questions can help to analyze the current preparation level and then strategize accordingly for the CBSE Class 12 Board Exam.

Before moving to the questions, here are a few important pointers.

  1. 10 questions are asked from the 2 marks section with 1 question having a choice.
  2. 2 marks questions should be written maximum in 2 to 3 lines i.e. 30 to 40 words.
  3. The answer needs to be a bit explanatory but should not include too many details.
  4. The board gives step markings for the answers i.e. for diagrams, terms, etc.
  5. It should be noted that the examiners might not consider additional or irrelevant points if the answer exceeds the word limit by a huge margin.

Students preparing for class 12 board exams are also suggested to check the important questions for Class 12 biology to get chapter-wise biology sample questions for the board exam.

Important 2 marks Biology Questions For Class 12 Exam

Question 1:

The ‘human male’ and ‘female bird’ are heterogametic while the ‘human female’ and ‘male bird’ are
homogametic. Why are they called so?

Question 2:

What is an allergy? Name the antibody responsible for it. Also, mention two chemicals released from the mast cells during an allergic reaction.

Question 3:

Fed up with a large family, a couple wanted to adopt a terminal method of contraception. Describe the process conducted by the doctor in either of the cases (male / female partner).

Question 4:

Mention the role of histone proteins in the packaging of DNA to form the structure of chromatin fibre.

Question 5:

Differentiate between:

(a) Grazing food chain and detritus food chain.

(b) Primary and secondary productivity.

Question 6:

How do the following help in cancer treatment?

(a) alpha Interferon

(b) radiotherapy.

Question 7:

(a) Differentiate between zoospore and zygote.

(b) Which parts of the flower develop into perisperm and pericarp?

Question 8:

State any three advanced methods of ex-situ conservation. In which way, do you think, are the advanced methods better than the traditional ex-situ methods?

Question 9:

What are the latest methods of detection of cancer?

Question 10:

State the microbes which help in the commercial production of the following products:

(a) Statin

(b) Citric acid

(c) Penicillin

(d) Butyric acid

Question 11:

Suggest two practices giving one example of each, that help protect rare or threatened species.

Question 12:

Give the binomials of two types of yeast and the commercial bioactive products they help to produce.

Question 13:

Differentiate between the genetic codes given below :

(a) Unambiguous and Universal

(b) Degenerate and Initiator

Question 14:

List the two methodologies which were involved in the human genome project. Mention how they were used.

Question 15:

Explain the following phases in the menstrual cycle of a human

female :

(a) Menstrual phase

(b) Follicular phase

Question 16:

What is an ecological pyramid? Write any two limitations of ecological pyramids.

Question 17:

Name the phenomenon, in which a single gene product produces more than one phenotypic effect. Give an example of it, one each from plants and humans.

Question 18:

Differentiate between male and female heterogamety.

Question 19:

Many freshwater animals can not survive in the marine environment. Explain.

Question 20:

Explain brood parasitism with the help of an example.

Question 21:

Name the two special types of lymphocytes in humans. How do they differ in their roles in immune response?

Question 22:

Name the bacterium that causes typhoid. Mention two diagnostic symptoms. How is this disease transmitted to others?

Question 23:

State the reasons for the following

(a) The human testes are located outside the abdominal cavity.

(b) Some organisms like honeybees are called parthenogenetic animals.

Question 24:

Write the cellular contents carried by the pollen tube. How does the pollen tube gain its entry into the embryo sac?

Question 25:

How does culturing Spirulina solve the food problems of the growing human population?

Question 26:

Why are small birds like hummingbirds not found in polar regions?

Question 27:

Name the product of fertilization that forms the kernel of the coconut. How does the kernel differ from coconut water?

Question 28:

Describe the role of lymph nodes in providing immunity.

Question 29:

What happens to the corpus luteum in the human female if the ovum is

(a) fertilized,

(b) not fertilized

Question 30:

Mention one application for each of the following :

(a) Passive immunization

(b) Antihistamine

(c) Colostrum

(d) Cytokinin-barrier

Question 31:

List the events that reduce the Biological Oxygen Demand (BOD) of a primary effluent
during sewage treatment.

Question 32:

Discuss the role the enzyme DNA ligase plays during DNA replication.


Why is reproduction essential for organisms?


Distinguish between monohybrid and dihybrid.

Question 35:

Define phenotypic adaptation.

Question 36:

Distinguish between primary and secondary sewage treatment?

Question 37:

What is biodiversity?

Question 38:

What are the structure and functions of the ecosystem?

Question 39:

List out the applications of Biotechnology in agriculture and medicines.

Question 40:

Distinguish between food chain and food web.

It should be noted that the CBSE board exams include questions only from the syllabus topics. The presentation of the answers matters a lot in the exam and writing unnecessary more words or points does not mean getting more marks. It is always suggested to stick to the main points and answer according to the marks of the respective questions. To get more sample questions, click CBSE question papers for class 12 biology.

Keep visiting BYJU’S to get more such important questions and preparation tips for the class 12 board exams.



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