Practice Question Paper — not an official CBSE document
Class 12 · Biology
Subject Code 044 · Set 1 of 3
Time allowed: 3 hoursMaximum marks: 7033 questions
Theory 70 + practical 30. This page is the 70-mark theory practice paper.
General instructions
This practice paper has 33 questions in five sections and is of 70 marks (theory). Practical / project work is separate (30 marks).
Section A: Q1–12 MCQ and Q13–16 Assertion–Reason, 1 mark each.
Section B: Q17–21 very short answers of 2 marks each.
Section C: Q22–28 short answers of 3 marks each.
Section D: Q29–30 case-study / source-based questions of 4 marks each.
Section E: Q31–33 long answers of 5 marks each. Internal choice is given in some questions.
There is no overall choice. Attempt only one option where an internal choice is given.
Practice questions aligned to NCERT topics used in CBSE classrooms. These are original exam-oriented questions for revision — not official CBSE board papers and not a guarantee of any exam question. Always match the textbook issued by your school and the latest PDFs on ncert.nic.in and cbseacademic.nic.in.
Section A
Objective type (MCQ and Assertion–Reason) · Q1–16 · 1 mark each · 16 marks
Q.1MCQPrinciples of Inheritance and Variation[1]
Choose the correct statement related to Textbook first in the chapter Principles of Inheritance and Variation.
Show answer / marking points
Answer / marking points
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
Note
Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.2MCQBiotechnology: Principles and Processes[1]
Choose the correct statement related to Diagrams in the chapter Biotechnology: Principles and Processes.
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Answer / marking points
C. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Note
If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.3MCQSexual Reproduction in Flowering Plants[1]
Choose the correct statement related to Practice in the chapter Sexual Reproduction in Flowering Plants.
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Answer / marking points
D. Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants
Note
Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.4MCQEvolution[1]
Choose the correct statement related to Evolution in the chapter Evolution.
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Answer / marking points
B. Homologous vs analogous
Note
Homologous vs analogous. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.5MCQOrganisms and Populations[1]
Choose the correct statement related to Organisms and Populations in the chapter Organisms and Populations.
Show answer / marking points
Answer / marking points
B. Organisms and Populations is an NCERT chapter taught in CBSE Class 12 Biology
Note
Organisms and Populations is an NCERT chapter taught in CBSE Class 12 Biology. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.6MCQReproductive Health[1]
Choose the correct statement related to Examples in the chapter Reproductive Health.
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Answer / marking points
A. CBSE often tests a concept by asking a daily-life example from the same chapter
Note
CBSE often tests a concept by asking a daily-life example from the same chapter. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.7MCQMicrobes in Human Welfare[1]
Choose the correct statement related to Accuracy in the chapter Microbes in Human Welfare.
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Answer / marking points
B. Use the terms used in the NCERT book; do not replace them with unofficial names
Note
Use the terms used in the NCERT book; do not replace them with unofficial names. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.8MCQBiodiversity and Conservation[1]
Choose the correct statement related to Biodiversity and Conservation in the chapter Biodiversity and Conservation.
Show answer / marking points
Answer / marking points
C. Latitudinal gradient
Note
Latitudinal gradient. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.9MCQMolecular Basis of Inheritance[1]
Choose the correct statement related to Molecular Basis of Inheritance in the chapter Molecular Basis of Inheritance.
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Answer / marking points
D. lac operon
Note
lac operon. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.10MCQBiotechnology and its Applications[1]
Choose the correct statement related to Keywords in the chapter Biotechnology and its Applications.
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Answer / marking points
B. Every chapter ends with keywords or a summary that is useful for one-mark answers
Note
Every chapter ends with keywords or a summary that is useful for one-mark answers. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.11MCQHuman Reproduction[1]
Choose the correct statement related to Revision in the chapter Human Reproduction.
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Answer / marking points
D. Write three points from Human Reproduction in your own words; that is enough for a short-answer start
Note
Write three points from Human Reproduction in your own words; that is enough for a short-answer start. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.12MCQHuman Health and Disease[1]
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
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Answer / marking points
B. Innate vs acquired immunity
Note
Innate vs acquired immunity. The other options mix ideas from nearby topics or reverse the textbook fact.
Q.13Assertion and ReasonEcosystem[1]
Assertion (A): Nutrient cycling: carbon, phosphorus.
Reason (R): Nutrient cycling is a key idea in the chapter Ecosystem.
Choose the correct option.
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Answer / marking points
A. Both A and R are true, and R is the correct explanation of A.
Note
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Q.14Assertion and ReasonPrinciples of Inheritance and Variation[1]
Assertion (A): Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions.
Reason (R): Textbook first is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
Show answer / marking points
Answer / marking points
A. Both A and R are true, and R is the correct explanation of A.
Note
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Q.15Assertion and ReasonBiotechnology: Principles and Processes[1]
Assertion (A): If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures.
Reason (R): Diagrams is a key idea in the chapter Biotechnology: Principles and Processes.
Choose the correct option.
Show answer / marking points
Answer / marking points
A. Both A and R are true, and R is the correct explanation of A.
Note
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Q.16Assertion and ReasonSexual Reproduction in Flowering Plants[1]
Assertion (A): Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants.
Reason (R): Practice is a key idea in the chapter Sexual Reproduction in Flowering Plants.
Choose the correct option.
Show answer / marking points
Answer / marking points
A. Both A and R are true, and R is the correct explanation of A.
Note
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Section B
Very Short Answer · Q17–21 · 2 marks each · 10 marks
Q.172 MarkEvolution[2]
Give two points to explain Evolution as used in Evolution.
Show answer / marking points
Answer / marking points
1. Homologous vs analogous.
2. Keep the NCERT wording and add one daily-life example from the same chapter.
Note
Two-mark answers work best as two numbered points. One definition plus one example is usually enough.
Q.182 MarkOrganisms and Populations[2]
Give two points to explain Organisms and Populations as used in Organisms and Populations.
Show answer / marking points
Answer / marking points
1. Organisms and Populations is an NCERT chapter taught in CBSE Class 12 Biology.
2. Keep the NCERT wording and add one daily-life example from the same chapter.
Note
Two-mark answers work best as two numbered points. One definition plus one example is usually enough.
Q.192 MarkReproductive Health[2]
Give two points to explain Examples as used in Reproductive Health.
Show answer / marking points
Answer / marking points
1. CBSE often tests a concept by asking a daily-life example from the same chapter.
2. Keep the NCERT wording and add one daily-life example from the same chapter.
Note
Two-mark answers work best as two numbered points. One definition plus one example is usually enough.
Q.202 MarkMicrobes in Human Welfare[2]
Give two points to explain Accuracy as used in Microbes in Human Welfare.
Show answer / marking points
Answer / marking points
1. Use the terms used in the NCERT book; do not replace them with unofficial names.
2. Keep the NCERT wording and add one daily-life example from the same chapter.
Note
Two-mark answers work best as two numbered points. One definition plus one example is usually enough.
Q.212 MarkBiodiversity and Conservation[2]
Give two points to explain Biodiversity and Conservation as used in Biodiversity and Conservation.
Show answer / marking points
Answer / marking points
1. Latitudinal gradient.
2. Keep the NCERT wording and add one daily-life example from the same chapter.
Note
Two-mark answers work best as two numbered points. One definition plus one example is usually enough.
Section C
Short Answer · Q22–28 · 3 marks each · 21 marks
Q.223 MarkMolecular Basis of Inheritance[3]
Explain Molecular Basis of Inheritance in about three points, with one example.
Show answer / marking points
Answer / marking points
lac operon. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Q.233 MarkBiotechnology and its Applications[3]
Explain Keywords in about three points, with one example.
Show answer / marking points
Answer / marking points
Every chapter ends with keywords or a summary that is useful for one-mark answers. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Q.243 MarkHuman Reproduction[3]
Explain Revision in about three points, with one example.
Show answer / marking points
Answer / marking points
Write three points from Human Reproduction in your own words; that is enough for a short-answer start. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Q.253 MarkHuman Health and Disease[3]
Explain Human Health and Disease in about three points, with one example.
Show answer / marking points
Answer / marking points
Innate vs acquired immunity. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Q.263 MarkEcosystem[3]
Explain Nutrient cycling in about three points, with one example.
Show answer / marking points
Answer / marking points
Nutrient cycling: carbon, phosphorus. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Q.273 MarkPrinciples of Inheritance and Variation[3]
Explain Textbook first in about three points, with one example.
OR
Explain Practice in about three points, with one example.
Show answer / marking points
Answer / marking points
Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
OR — marking points
Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Q.283 MarkBiotechnology: Principles and Processes[3]
Explain Diagrams in about three points, with one example.
OR
Explain Evolution in about three points, with one example.
Show answer / marking points
Answer / marking points
If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Note
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
OR — marking points
Homologous vs analogous. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Section D
Case-study / source-based · Q29–30 · 4 marks each · 8 marks
Q.29Case BasedSexual Reproduction in Flowering Plants[4]
A student is revising Sexual Reproduction in Flowering Plants and notes: “Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Show answer / marking points
Answer / marking points
(i) Practice.
(ii) Mix MCQs with short answers so you remember both facts and explanations from Sexual Reproduction in Flowering Plants.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Note
Case-based items recycle a short story. Pull the fact out first, then apply it. This is original practice in CBSE case style — not a copied board paper.
Q.30Case BasedEvolution[4]
A student is revising Evolution and notes: “Homologous vs analogous.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Show answer / marking points
Answer / marking points
(i) Evolution.
(ii) Homologous vs analogous.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Note
Case-based items recycle a short story. Pull the fact out first, then apply it. This is original practice in CBSE case style — not a copied board paper.
Section E
Long Answer · Q31–33 · 5 marks each · 15 marks
Q.315 MarkOrganisms and Populations[5]
Write a long answer on Organisms and Populations. Include definition, explanation and one application.
Show answer / marking points
Answer / marking points
Organisms and Populations — Organisms and Populations is an NCERT chapter taught in CBSE Class 12 Biology. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Note
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Q.325 MarkReproductive Health[5]
Write a long answer on Examples. Include definition, explanation and one application.
OR
Write a long answer on Biodiversity and Conservation. Include definition, explanation and one application.
Show answer / marking points
Answer / marking points
Examples — CBSE often tests a concept by asking a daily-life example from the same chapter. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Note
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
OR — marking points
Biodiversity and Conservation — Latitudinal gradient. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Q.335 MarkMicrobes in Human Welfare[5]
Write a long answer on Accuracy. Include definition, explanation and one application.
OR
Write a long answer on Molecular Basis of Inheritance. Include definition, explanation and one application.
Show answer / marking points
Answer / marking points
Accuracy — Use the terms used in the NCERT book; do not replace them with unofficial names. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Note
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
OR — marking points
Molecular Basis of Inheritance — lac operon. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
