Class 12 Biology Principles of Inheritance and Variation Previous Year Style Questions
Previous Year Style Questions for Class 12 Biology Principles of Inheritance and Variation. Try first, then reveal the answer. These are exam-oriented practice items, not copied board papers.
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.
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Practice set
Q1MCQ1 markEasyRevision pick
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. CBSE often tests a concept by asking a daily-life example from the same chapter
B. Laws of inheritance
C. Sex-linked inheritance
D. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
Answer
B. Laws of inheritance
Explanation
Laws of inheritance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q2MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Incomplete dominance, co-dominance
B. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
C. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
D. Pedigree
Answer
A. Incomplete dominance, co-dominance
Explanation
Incomplete dominance, co-dominance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q3MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Every chapter ends with keywords or a summary that is useful for one-mark answers
B. Mendelian and chromosomal disorders
C. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
D. Sex-linked inheritance
Answer
D. Sex-linked inheritance
Explanation
Sex-linked inheritance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q4MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Pedigree
B. Use the terms used in the NCERT book; do not replace them with unofficial names
C. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
D. CBSE often tests a concept by asking a daily-life example from the same chapter
Answer
A. Pedigree
Explanation
Pedigree. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q5MCQ1 markModerateRevision pick
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Mendelian and chromosomal disorders
B. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
C. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
A. Mendelian and chromosomal disorders
Explanation
Mendelian and chromosomal disorders. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q6MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
B. Pedigree
C. Every chapter ends with keywords or a summary that is useful for one-mark answers
D. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
Answer
A. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
Explanation
Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q7MCQ1 markEasy
Choose the correct statement related to Textbook first in the chapter Principles of Inheritance and Variation.
A. The textbook says the opposite of this statement
B. CBSE often tests a concept by asking a daily-life example from the same chapter
C. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
D. Use the terms used in the NCERT book; do not replace them with unofficial names
Answer
C. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q8MCQ1 markEasy
Choose the correct statement related to Keywords in the chapter Principles of Inheritance and Variation.
A. This happens only in a laboratory and never in daily life
B. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
C. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
D. Every chapter ends with keywords or a summary that is useful for one-mark answers
Answer
D. Every chapter ends with keywords or a summary that is useful for one-mark answers
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q9MCQ1 markEasyRevision pick
Choose the correct statement related to Examples in the chapter Principles of Inheritance and Variation.
A. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
B. This idea is not part of the NCERT chapter
C. Laws of inheritance
D. CBSE often tests a concept by asking a daily-life example from the same chapter
Answer
D. CBSE often tests a concept by asking a daily-life example from the same chapter
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q10MCQ1 markModerate
Choose the correct statement related to Diagrams in the chapter Principles of Inheritance and Variation.
A. Use the terms used in the NCERT book; do not replace them with unofficial names
B. The textbook says the opposite of this statement
C. Incomplete dominance, co-dominance
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q11MCQ1 markEasy
Choose the correct statement related to Revision in the chapter Principles of Inheritance and Variation.
A. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
B. Sex-linked inheritance
C. This happens only in a laboratory and never in daily life
D. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
Answer
D. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
Explanation
Write three points from Principles of Inheritance and Variation 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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q12MCQ1 markEasy
Choose the correct statement related to Accuracy in the chapter Principles of Inheritance and Variation.
A. Laws of inheritance
B. This idea is not part of the NCERT chapter
C. Use the terms used in the NCERT book; do not replace them with unofficial names
D. Pedigree
Answer
C. Use the terms used in the NCERT book; do not replace them with unofficial names
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q13MCQ1 markEasyRevision pick
Choose the correct statement related to Practice in the chapter Principles of Inheritance and Variation.
A. Mendelian and chromosomal disorders
B. The textbook says the opposite of this statement
C. Incomplete dominance, co-dominance
D. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
Answer
D. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
Explanation
Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q14MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
B. This happens only in a laboratory and never in daily life
C. Laws of inheritance
D. Pedigree
Answer
C. Laws of inheritance
Explanation
Laws of inheritance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q15MCQ1 markModerate
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Incomplete dominance, co-dominance
B. Mendelian and chromosomal disorders
C. Every chapter ends with keywords or a summary that is useful for one-mark answers
D. Laws of inheritance
Answer
A. Incomplete dominance, co-dominance
Explanation
Incomplete dominance, co-dominance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q16MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Incomplete dominance, co-dominance
B. Sex-linked inheritance
C. CBSE often tests a concept by asking a daily-life example from the same chapter
D. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
Answer
B. Sex-linked inheritance
Explanation
Sex-linked inheritance. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q17MCQ1 markEasyRevision pick
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Sex-linked inheritance
B. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
C. Pedigree
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
C. Pedigree
Explanation
Pedigree. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q18MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Pedigree
B. Mendelian and chromosomal disorders
C. Every chapter ends with keywords or a summary that is useful for one-mark answers
D. Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start
Answer
B. Mendelian and chromosomal disorders
Explanation
Mendelian and chromosomal disorders. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q19MCQ1 markEasy
Choose the correct statement related to Principles of Inheritance and Variation in the chapter Principles of Inheritance and Variation.
A. Incomplete dominance, co-dominance
B. This topic is only for college
C. Mendelian and chromosomal disorders
D. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
Answer
D. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
Explanation
Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q20MCQ1 markModerate
Choose the correct statement related to Textbook first in the chapter Principles of Inheritance and Variation.
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
B. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
C. Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology
D. Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation
Answer
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q413 Mark3 marksModerateRevision pick
Explain Principles of Inheritance and Variation in about three points, with one example.
Answer
Incomplete dominance, co-dominance. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q423 Mark3 marksModerate
Explain Principles of Inheritance and Variation in about three points, with one example.
Answer
Sex-linked inheritance. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q433 Mark3 marksModerate
Explain Principles of Inheritance and Variation in about three points, with one example.
Answer
Pedigree. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q443 Mark3 marksDifficult
Explain Principles of Inheritance and Variation in about three points, with one example.
Answer
Mendelian and chromosomal disorders. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q453 Mark3 marksModerateRevision pick
Explain Principles of Inheritance and Variation in about three points, with one example.
Answer
Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q463 Mark3 marksModerate
Explain Textbook first in about three points, with one example.
Answer
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.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q473 Mark3 marksModerate
Explain Keywords in about three points, with one example.
Answer
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.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q483 Mark3 marksDifficult
Explain Examples in about three points, with one example.
Answer
CBSE often tests a concept by asking a daily-life example from the same chapter. Example: Use a situation from the NCERT activity or a labelled diagram in this chapter.
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q555 Mark5 marksModerate
Write a long answer on Principles of Inheritance and Variation. Include definition, explanation and one application.
Answer
Principles of Inheritance and Variation — Sex-linked inheritance. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q565 Mark5 marksModerate
Write a long answer on Principles of Inheritance and Variation. Include definition, explanation and one application.
Answer
Principles of Inheritance and Variation — Pedigree. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q575 Mark5 marksDifficultRevision pick
Write a long answer on Principles of Inheritance and Variation. Include definition, explanation and one application.
Answer
Principles of Inheritance and Variation — Mendelian and chromosomal disorders. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q585 Mark5 marksModerate
Write a long answer on Principles of Inheritance and Variation. Include definition, explanation and one application.
Answer
Principles of Inheritance and Variation — Principles of Inheritance and Variation 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.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q595 Mark5 marksModerate
Write a long answer on Textbook first. Include definition, explanation and one application.
Answer
Textbook first — Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q605 Mark5 marksDifficult
Write a long answer on Keywords. Include definition, explanation and one application.
Answer
Keywords — Every chapter ends with keywords or a summary that is useful for one-mark answers. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q61Assertion and Reason1 markModerate
Assertion (A): CBSE often tests a concept by asking a daily-life example from the same chapter.
Reason (R): Examples is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q62Assertion and Reason1 markModerate
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 Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q63Assertion and Reason1 markModerate
Assertion (A): Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start.
Reason (R): Revision is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q64Assertion and Reason1 markDifficult
Assertion (A): Use the terms used in the NCERT book; do not replace them with unofficial names.
Reason (R): Accuracy is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q65Assertion and Reason1 markModerate
Assertion (A): Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation.
Reason (R): Practice is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q66Assertion and Reason1 markModerate
Assertion (A): Laws of inheritance.
Reason (R): Principles of Inheritance and Variation is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q67Assertion and Reason1 markModerate
Assertion (A): Incomplete dominance, co-dominance.
Reason (R): Principles of Inheritance and Variation is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q68Assertion and Reason1 markDifficult
Assertion (A): Sex-linked inheritance.
Reason (R): Principles of Inheritance and Variation is a key idea in the chapter Principles of Inheritance and Variation.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q69Case Based4 marksModerateRevision pick
A student is revising Principles of Inheritance and Variation and notes: “Pedigree.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Principles of Inheritance and Variation.
(ii) Pedigree.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q70Case Based4 marksModerate
A student is revising Principles of Inheritance and Variation and notes: “Mendelian and chromosomal disorders.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Principles of Inheritance and Variation.
(ii) Mendelian and chromosomal disorders.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q71Case Based4 marksModerate
A student is revising Principles of Inheritance and Variation and notes: “Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Principles of Inheritance and Variation.
(ii) Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q72Case Based4 marksDifficult
A student is revising Principles of Inheritance and Variation and notes: “Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Textbook first.
(ii) Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q73Case Based4 marksModerateRevision pick
A student is revising Principles of Inheritance and Variation and notes: “Every chapter ends with keywords or a summary that is useful for one-mark answers.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Keywords.
(ii) Every chapter ends with keywords or a summary that is useful for one-mark answers.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q74Case Based4 marksModerate
A student is revising Principles of Inheritance and Variation and notes: “CBSE often tests a concept by asking a daily-life example from the same chapter.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Examples.
(ii) CBSE often tests a concept by asking a daily-life example from the same chapter.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q75Case Based4 marksModerate
A student is revising Principles of Inheritance and Variation and notes: “If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Diagrams.
(ii) If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q76Case Based4 marksDifficult
A student is revising Principles of Inheritance and Variation and notes: “Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Revision.
(ii) Write three points from Principles of Inheritance and Variation in your own words; that is enough for a short-answer start.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
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.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q77Competency Based3 marksModerateRevision pick
Competency practice: A classmate can recall the heading Accuracy but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Use the terms used in the NCERT book; do not replace them with unofficial names. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q78Competency Based3 marksDifficult
Competency practice: A classmate can recall the heading Practice but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Mix MCQs with short answers so you remember both facts and explanations from Principles of Inheritance and Variation. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q79Competency Based3 marksModerate
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Laws of inheritance. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q80Competency Based3 marksModerate
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Incomplete dominance, co-dominance. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q81Competency Based3 marksDifficultRevision pick
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Sex-linked inheritance. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q82Competency Based3 marksModerate
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Pedigree. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q83Competency Based3 marksModerate
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Mendelian and chromosomal disorders. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q84Competency Based3 marksDifficult
Competency practice: A classmate can recall the heading Principles of Inheritance and Variation but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Principles of Inheritance and Variation is an NCERT chapter taught in CBSE Class 12 Biology. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
Meta
Class: Class 12 · Subject: Biology · Chapter: Principles of Inheritance and Variation · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
FAQs
Are these official CBSE board questions?
No. They are original practice questions aligned to NCERT topics used in CBSE classrooms. Official sample papers are published on cbseacademic.nic.in.
Will these questions appear in the board exam?
Nobody can promise a question. Use them for revision of frequently tested concepts and exam-style practice.
Is the chapter list the latest NCERT list?
Yes, the catalog follows current NCERT textbooks used in CBSE schools (including new middle-stage books such as Ganita Prakash and Curiosity). Always match the book issued by your school.
How should I use the 100 questions?
Try the question first, then tap Show answer. Mix MCQs with long answers. Revise formulas and diagrams from the textbook alongside this set.
Where are NCERT solutions?
Open the NCERT-style practice link on this subject or chapter. For word-for-word textbook exercise answers, use the NCERT book itself; we do not copy solution keys from other websites.
What is the suggested URL pattern?
Hub /cbse/, then /cbse/class-12/, then subject and chapter slugs.
Why is this a separate URL?
So students searching for “Previous Year Style Questions” land on a filtered set, while the chapter page remains the full 100-question bank. Same facts, different search intent.
Today's 3-step path
Follow this loop every day: mixed test, current affairs, then today's subject. A new set arrives tomorrow.
