Ultimate Practice Set: Essential Ishihara Test Colour Blindness MCQs for Class 12 Biology for NEET, JEE & CUET

Understanding visual genetics becomes far more engaging when aspirants regularly practice with Ishihara Test Colour Blindness MCQs for Class 12 Biology. These resources help simplify one of the most important applications of sex-linked inheritance in humans. Colour blindness, especially red-green colour blindness, is a classic example of X-linked recessive inheritance, and practicing through Ishihara Test Colour Blindness MCQs for Class 12 Biology allows aspirants to connect theory with real-world diagnostic tools. The Ishihara test itself is widely used in clinical and educational settings, and mastering its concept through Ishihara Test Colour Blindness MCQs for Class 12 Biology strengthens both conceptual clarity and exam readiness.

When aspirants explore inheritance patterns using Ishihara Test Colour Blindness MCQs for Class 12 Biology, they begin to understand why males are more commonly affected than females. Since males possess only one X chromosome, the presence of a defective allele directly expresses the condition. This fundamental idea becomes clearer when repeatedly reinforced through Ishihara Test Colour Blindness MCQs for Class 12 Biology, where questions are designed to test pedigree analysis, genotype prediction, and probability-based outcomes.

Another important advantage of solving Ishihara Test Colour Blindness MCQs for Class 12 Biology is that it helps bridge the gap between theoretical genetics and applied biology. Aspirants are not just memorizing inheritance laws—they are actively applying them to real diagnostic methods. The Ishihara plates, which consist of colored dots forming numbers or patterns, are directly linked to genetic concepts. Practicing Ishihara Test Colour Blindness MCQs for Class 12 Biology ensures that learners can interpret both the biological basis and the practical use of such tests.

In competitive exams like NEET and CUET, questions often require logical thinking rather than direct recall. This is where Ishihara Test Colour Blindness MCQs for Class 12 Biology play a crucial role. They train aspirants to analyze situations, such as predicting the chances of offspring being colorblind or identifying carriers in a family. By consistently solving Ishihara Test Colour Blindness MCQs for Class 12 Biology, aspirants develop confidence in handling complex genetics problems under time pressure.

Moreover, repeated exposure to Ishihara Test Colour Blindness MCQs for Class 12 Biology enhances understanding of related concepts like carriers, heterozygosity, and sex-linked disorders. For example, a heterozygous female may not show symptoms but can pass the allele to her offspring. These subtle yet important ideas are best learned through application, and Ishihara Test Colour Blindness MCQs for Class 12 Biology provide exactly that opportunity.

From a conceptual standpoint, Ishihara Test Colour Blindness MCQs for Class 12 Biology also reinforce Mendel’s laws in a broader context. While Mendel did not study sex-linked traits, modern genetics extends his principles to explain conditions like color blindness. Practicing Ishihara Test Colour Blindness MCQs for Class 12 Biology helps aspirants see how classical genetics evolves into more advanced topics, making learning more interconnected and meaningful.

Additionally, Ishihara Test Colour Blindness MCQs for Class 12 Biology are highly useful for revision. Instead of going through lengthy notes, aspirants can quickly test their understanding and identify weak areas. This active recall method improves retention and ensures that concepts stay fresh before exams. Regular practice with Ishihara Test Colour Blindness MCQs for Class 12 Biology can significantly boost accuracy and speed.

Ishihara Test Colour Blindness MCQs for Class 12 Biology:

1. The Drosophila with the karyotype AAA + XX is

A. Intersex
B. Female
C. Metafemale
D. Metamale

Answer: A
Explanation: In Drosophila melanogaster, sex depends on X:A ratio. AAA+XX gives an intermediate ratio → intersex.

2. Which of the following symbols are used for representing chromosome of birds?

A. ZZ–ZW
B. XX–XY
C. XO–XX
D. ZZ–WW

Answer: A
Explanation: Birds follow ZW system → male = ZZ, female = ZW.

3. A couple has 6 children (5 girls, 1 boy). Probability of next child being a girl is

A. 10%
B. 20%
C. 50%
D. 100%

Answer: C
Explanation: Each birth is independent → probability always 50%.

4. Which type of sex determination is found in grasshopper?

A. XY
B. WZ
C. XO
D. All of these

Answer: C
Explanation: Grasshoppers show XX–XO system.

5. Autosomes in humans are

A. 11 pairs
B. 22 pairs
C. 23 pairs
D. 43 pairs

Answer: B
Explanation: Humans have 22 pairs autosomes + 1 pair sex chromosomes.

6. Where does gene TDF occur in humans?

A. Y chromosome
B. X chromosome
C. Both
D. Autosomes

Answer: A
Explanation: TDF (SRY gene) present on Y chromosome → male development.

7. Number of autosome pairs in Drosophila is

A. 2
B. 3
C. 4
D. 5

Answer: B
Explanation: 3 pairs autosomes + 1 pair sex chromosomes.

8. X/A ratio for super female in Drosophila is

A. 0.5
B. 1
C. 1.5
D. 2

Answer: C
Explanation: X/A ≥ 1.5 → metafemale.

9. Normal chromosome number in humans is

A. 42
B. 44
C. 46
D. 48

Answer: C
Explanation: Humans have 46 chromosomes (23 pairs), including 22 pairs of autosomes and 1 pair of sex chromosomes.

10. The 23rd pair of chromosomes in humans is called

A. Chromatid
B. Heterosome
C. Autosome
D. Gene

Answer: B
Explanation: The 23rd pair consists of sex chromosomes (XX or XY), also called heterosomes.

11. Hypertrichosis is an example of

A. Holandric inheritance
B. Sex influenced inheritance
C. Sex linked inheritance
D. Autosomal inheritance

Answer: A
Explanation: Hypertrichosis is a Y-linked trait passed from father to son (holandric inheritance).

12. Male sex in humans is determined by

A. Nutrition of mother
B. Strength of father
C. Chromosome of egg
D. Chromosome of sperm

Answer: D
Explanation: The sperm determines sex by carrying either X or Y chromosome.

13. Ishihara chart is used to detect

A. Tuberculosis
B. Eye sight
C. Colour blindness
D. Diabetes

Answer: C
Explanation: Ishihara plates are used to test color vision deficiency.

14. Reciprocal cross gives different results in

A. Monohybrid cross
B. Cytoplasmic inheritance
C. Nuclear inheritance
D. Dihybrid cross

Answer: B
Explanation: Cytoplasmic inheritance depends on maternal cytoplasm, so reciprocal crosses differ.

15. Female sex in Drosophila is determined by

A. Y chromosome
B. Autosomes
C. X and Y chromosomes
D. X chromosome

Answer: D
Explanation: In Drosophila, sex depends on X:A ratio, mainly influenced by X chromosomes.

16. Disease affecting only sons indicates

A. Autosomal dominant
B. Sex-linked dominant
C. Sex-limited
D. Sex-linked recessive

Answer: D
Explanation: X-linked recessive disorders appear mostly in males.

17. Percentage of colorblind sons from carrier mother is

A. 75%
B. 50%
C. 25%
D. 100%

Answer: B
Explanation: Carrier mother (XᶜX) gives 50% chance of affected sons.

18. Hemophilic man × normal woman produces

A. All hemophilic children
B. All normal children
C. Hemophilic daughters
D. Hemophilic sons

Answer: B
Explanation: Sons receive normal X from mother → unaffected; daughters become carriers.

19. Sex determination in humans is called

A. Heterogamety
B. Haemopoiesis
C. Transgenesis
D. Parthenogenesis

Answer: A
Explanation: Males are heterogametic (XY), producing two types of gametes.

20. Diploid cells contain

A. One chromosome
B. One set
C. One pair
D. Two sets

Answer: D
Explanation: Diploid cells have two complete sets of chromosomes (2n).

21. Key factor in sex determination is

A. X chromosome
B. Autosome
C. Sex chromosome
D. Y chromosome

Answer: D
Explanation: Presence of Y chromosome determines male sex.

22. Example of sex-influenced inheritance

A. Hemophilia
B. Colour blindness
C. Baldness
D. Down syndrome

Answer: C
Explanation: Baldness shows different expression in males and females.

23. XXY condition leads to

A. Klinefelter syndrome
B. Turner syndrome
C. Down syndrome
D. Normal female

Answer: A
Explanation: XXY individuals are males with Klinefelter syndrome.

24. XXY condition in Drosophila results in

A. Female
B. Male
C. Intersex
D. Lethal

Answer: A
Explanation: In Drosophila, XXY gives female due to X:A ratio.

25. Human egg contains

A. Y chromosome
B. XX
C. X chromosome
D. XY

Answer: C
Explanation: Egg always carries one X chromosome.

26. Chromosomal basis of sex determination discovered in

A. Rumex
B. Coccinia
C. Melandrium
D. Sphaerocarpus

Answer: C
Explanation: Sex chromosomes were first identified in Melandrium.

27. Sex-linked inheritance occurs through

A. Autosomes
B. Y chromosome
C. X chromosome
D. Both X and Y chromosomes

Answer: D
Explanation: Sex-linked traits can be on X or Y chromosomes.

28. Barr body is associated with

A. Female sex chromosome
B. Male sex chromosome
C. Autosomes
D. Genes

Answer: A
Explanation: Barr body is an inactive X chromosome in females.

29. Sex determination depends on

A. Father
B. Mother
C. Both equally
D. Environment

Answer: A
Explanation: Father contributes X or Y chromosome, determining sex.

30. Human female chromosome set and ovum contain

A. 44+XX, 44+XX
B. 44+XX, 22+X
C. 22, 22
D. 44, 44

Answer: B
Explanation: Female has 44 autosomes + XX; ovum carries 22 autosomes + X.

Conclusion on Ishihara Test Colour Blindness MCQs for Class 12 Biology

In conclusion, mastering genetics requires both conceptual clarity and consistent practice, and Ishihara Test Colour Blindness MCQs for Class 12 Biology provide the perfect combination of both. They help aspirants understand inheritance patterns, apply theoretical knowledge, and prepare effectively for competitive exams. By incorporating Ishihara Test Colour Blindness MCQs for Class 12 Biology into daily study routines, learners can build a strong foundation in genetics and approach exam questions with confidence.