NEET UG · Biology · Principles of Inheritance and Variation

Mendelian Inheritance: NEET previous year questions

20 questions in ten years of NEET, in 9 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 20; about 1.9 per paper
Years asked: 9/10; last asked 2026
Chance of a question next paper: 84%; historical rate, how we compute it
Weighted estimate: 1.8; model; history: 1.9 a paper on average, typically 1–3

Key findings

01
Asked in 9 of 10 papers, 20 questions in all: #14 of 204 topics by ten-year total. It comes back every 1.1 years on average.
02
76% of its questions since 2018 tested an idea never asked before; 1 repeated an idea from the year before.
03
The most repeated idea is ABO Blood Group Inheritance, asked 3 times (2017, 2018, 2026), usually as “count correct features of abo inheritance”.
04
NEET has asked 15 of the 82 ideas in this topic; 58 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (70%); 50% easy, 0% hard, and up from 1.8 to 2.2 questions a paper since 2024.

Questions per year

Up to 2023: 1.8; per paper
Since 2024: 2.2; +0.4
Usual gap: 1.1 yrs; between papers asking it
Swing: ±1.3; questions, year to year

Recent framings

assertion-reason on Mendelian inheritance
identify impossible parental genotype combination
match list on genetics terms

Revise first

ABO Blood Group Inheritance (2017 2018 2026); Mendel's Seven Contrasting Traits (2026); ABO Blood Group System (2020 2024)

How it is asked

Difficulty, format and skill

Across all 20 questions on Mendelian Inheritance since 2017.

Difficulty

QUESTIONS

1010

Easy10 · 50%
Medium10 · 50%
Hard0 · 0%

Format

One-line MCQ · 14 Q70%
Other · 3 Q15%
Assertion–reason · 1 Q5%
Match the lists · 1 Q5%
Two statements · 1 Q5%

Skill tested

Recall · 9 Q45%
Concept · 5 Q25%
Application · 3 Q15%
Multi-step · 2 Q10%
Calculation · 1 Q5%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 15 of the 82 ideas in this topic. 58 have never been asked yet.

15958

Asked directly15 · 18%
Touched inside another question9 · 11%
Never asked58 · 71%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated3 · 15%15%3/10
- 2026 · Q169
  For a person with blood group 'O', which of the following is not a possible combination of parents' blood group genotypes ?
  mediumOne-line MCQ
- 2018 · Q180
  Which of the following characteristics represent 'Inheritance of blood groups' in humans ? a. Dominance b. Co-dominance c. Multiple allele…
  easyOtherAsked the year before
- 2017 · Q134
  The genotypes of a Husband and Wife are $I^AI^B$ and $I^Ai$ . Among the blood types of their children, how many different genotypes and…
  mediumOne-line MCQNew idea
Repeated3 · 15%15%3/10
Repeated2 · 10%10%2/10
2 · 10%10%1/102
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

15 different ideas were tested; 4 came more than once. Monohybrid Punnett Square is the foundation for 22 other ideas in the syllabus.

ABO Blood Group Inheritance3×
count correct features of abo inheritance
One-line MCQ · 6% next
ABO Blood Group System2×
identify incorrect statement on abo alleles
Other · 6% next
Mendel's Seven Contrasting Traits2×
statement i/ii on mendel experiments
One-line MCQ · 6% next · foundation for 2
Monohybrid Punnett Square2×
definition recall
One-line MCQ · 6% next · foundation for 22
Mendel's Seven Contrasting Traits1×
assertion-reason on mendelian inheritance
Assertion–reason · 6% next
Back Cross vs Test Cross1×
match list on genetics terms
Match the lists · 6% next · foundation for 2
Examples of Incomplete Dominance1×
predict phenotypes of a cross
One-line MCQ · 6% next
Law of Dominance Postulates1×
count correct statements on mendel's laws
Other · 6% next
Test Cross Application1×
identify genotype for test cross
One-line MCQ · 6% next · foundation for 5
Pleiotropy1×
definition recall
One-line MCQ · 4% next · foundation for 4
True-Breeding Lines1×
definition recall on mendel's experiments
One-line MCQ · 4% next · foundation for 2
Incomplete Dominance1×
incorrect statement selection on incomplete dominance
One-line MCQ · 4% next · foundation for 3
Inventor of the Punnett Square1×
true statement selection on genetics terms
One-line MCQ · 4% next
Starch Grain Size Exception1×
wrongly matched pair among genetics terms
One-line MCQ · 4% next
Mendel's Experiment Timeline1×
definition recall
One-line MCQ · 4% next

Idea	Times	Format	Chance next	Foundation for
ABO Blood Group Inheritancecount correct features of abo inheritance	3	One-line MCQApplication	6%	–
ABO Blood Group Systemidentify incorrect statement on abo alleles	2	OtherConcept	6%	–
Mendel's Seven Contrasting Traitsstatement i/ii on mendel experiments	2	One-line MCQRecall	6%	2 ideas
Monohybrid Punnett Squaredefinition recall	2	One-line MCQCalculation	6%	22 ideas
Mendel's Seven Contrasting Traitsassertion-reason on mendelian inheritance	1	Assertion–reasonConcept	6%	–
Back Cross vs Test Crossmatch list on genetics terms	1	Match the listsRecall	6%	2 ideas
Examples of Incomplete Dominancepredict phenotypes of a cross	1	One-line MCQApplication	6%	–
Law of Dominance Postulatescount correct statements on mendel's laws	1	OtherConcept	6%	–
Test Cross Applicationidentify genotype for test cross	1	One-line MCQApplication	6%	5 ideas
Pleiotropydefinition recall	1	One-line MCQRecall	4%	4 ideas
True-Breeding Linesdefinition recall on mendel's experiments	1	One-line MCQRecall	4%	2 ideas
Incomplete Dominanceincorrect statement selection on incomplete dominance	1	One-line MCQConcept	4%	3 ideas
Inventor of the Punnett Squaretrue statement selection on genetics terms	1	One-line MCQRecall	4%	–
Starch Grain Size Exceptionwrongly matched pair among genetics terms	1	One-line MCQRecall	4%	–
Mendel's Experiment Timelinedefinition recall	1	One-line MCQRecall	4%	–

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

Mendelian Inheritance questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20262 questions

Q169
For a person with blood group 'O', which of the following is not a possible combination of parents' blood group genotypes ?
Idea: ABO Blood Group Inheritance
MediumOne-line MCQ
Q175
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: In an experiment,…
Idea: Mendel's Seven Contrasting Traits
New ideaEasyAssertion–reason

NEET 20245 questions

Q113
Match List I with List II List I | List II A. Two or more alternative forms of a gene | I. Back cross B. Cross of F $_1$ progeny with…
Idea: Back Cross vs Test Cross
New ideaEasyMatch the lists
Q118
Which one of the following can be explained on the basis of Mendel's Law of Dominance? A. Out of one pair of factors one is dominant and…
Idea: Law of Dominance Postulates
New ideaMediumOther
Q126
A pink flowered Snapdragon plant was crossed with a red flowered Snapdragon plant. What type of phenotype/s is/are expected in the progeny?
Idea: Examples of Incomplete Dominance
New ideaMediumOne-line MCQ
Q135
In a plant, black seed color (BB/Bb) is dominant over white seed color (bb). In order to find out the genotype of the black seed plant,…
Idea: Test Cross Application
New ideaEasyOne-line MCQ
Q190
As per ABO blood grouping system, the blood group of father is B $^+$ , mother is A $^+$ and child is O $^+$ . Their respective genotype can be…
Idea: ABO Blood Group System
MediumOther

NEET 20231 question

Q133
The phenomenon of pleiotropism refers to
Idea: Pleiotropy
New ideaEasyOne-line MCQ

NEET 20221 question

Q126
Given below are two statements : Statement I : Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of…
Idea: Mendel's Seven Contrasting Traits
MediumTwo statements

NEET 20212 questions

Q125
The production of gametes by the parents, formation of zygotes, the $F_1$ and $F_2$ plants, can be understood from a diagram called :
Idea: Monohybrid Punnett Square
New ideaEasyOne-line MCQ
Q179
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased ?
Idea: Monohybrid Punnett Square
New ideaEasyOne-line MCQ

NEET 20202 questions

Q6
Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups.
Idea: ABO Blood Group System
New ideaMediumOne-line MCQ
Q61
How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits ?
Idea: True-Breeding Lines
New ideaEasyOne-line MCQ

NEET 20191 question

Q147
In Antirrhinum (Snapdragon), a red flower was crossed with a white flower and in $F_1$ generation, pink flowers were obtained. When pink…
Idea: Incomplete Dominance
New ideaMediumOne-line MCQ

NEET 20183 questions

Q104
Which of the following pairs is wrongly matched ?
Idea: Starch Grain Size Exception
New ideaMediumOne-line MCQ
Q105
Select the correct statement :
Idea: Inventor of the Punnett Square
New ideaMediumOne-line MCQ
Q180
Which of the following characteristics represent 'Inheritance of blood groups' in humans ? a. Dominance b. Co-dominance c. Multiple allele…
Idea: ABO Blood Group Inheritance
Asked last yearEasyOther

NEET 20173 questions

Q134
The genotypes of a Husband and Wife are $I^AI^B$ and $I^Ai$ . Among the blood types of their children, how many different genotypes and…
Idea: ABO Blood Group Inheritance
MediumOne-line MCQ
Q147
Among the following characters, which one was not considered by Mendel in his experiments on pea ?
Idea: Mendel's Seven Contrasting Traits
EasyOne-line MCQ
Q151
Which one from those given below is the period for Mendel's hybridization experiments ?
Idea: Mendel's Experiment Timeline
EasyOne-line MCQ

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.