4. Principles of Inheritance and Variation

*नोट: यह सेक्शन रिवीजन के लिए है। अपना ज्ञान परखने के लिए ऊपर दिए गए क्विज़ में भाग लें।

1. Who is known as the Father of Genetics?
   A) Charles Darwin  |  B) Gregor Johann Mendel  |  C) T.H. Morgan  |  D) Hugo de Vries
2. Which plant did Mendel choose for his experiments?
   A) Wild pea  |  B) Garden pea (Pisum sativum)  |  C) Sweet pea  |  D) Rose
3. What is a pair of contrasting traits called?
   A) Gene  |  B) Allele  |  C) Phenotype  |  D) Genotype
4. What is the phenotype ratio of Mendel's monohybrid cross?
   A) 1:2:1  |  B) 3:1  |  C) 9:3:3:1  |  D) 1:1
5. Who proposed the Chromosomal theory of inheritance?
   A) Mendel  |  B) Sutton & Boveri  |  C) Watson & Crick  |  D) Morgan
6. In humans, sex determination is done by which chromosome?
   A) Autosome  |  B) Allosome (X and Y)  |  C) RNA  |  D) None
7. What type of disorder is Haemophilia?
   A) Sex-linked recessive  |  B) Autosomal dominant  |  C) Chromosomal  |  D) Infectious
8. Main cause of Down's Syndrome is?
   A) Trisomy of 21st chromosome  |  B) Lack of X  |  C) XYY condition  |  D) Lack of 21st
9. What are alternative forms of a gene called?
   A) Factor  |  B) Allele  |  C) Cistron  |  D) Muton
10. Which of Mendel's laws is also called the 'Law of Purity of Gametes'?
    A) Law of Dominance  |  B) Law of Segregation  |  C) Independent Assortment  |  D) None
11. Sickle-cell anaemia is what type of disease?
    A) Bacterial  |  B) Genetic (Mendelian disorder)  |  C) Vitamin deficiency  |  D) Pollution related
12. How many pairs of chromosomes are found in humans?
    A) 22 pairs  |  B) 23 pairs (Total 46)  |  C) 46 pairs  |  D) 21 pairs
13. What does Phenotype mean?
    A) Genetic makeup  |  B) Physical appearance  |  C) Cell structure  |  D) Gene sequence
14. Chromosome status in Turner's Syndrome is?
    A) 44 + XXY  |  B) 44 + XO  |  C) 44 + XYY  |  D) 45 + XX
15. How many pairs of contrasting traits in pea did Mendel study?
    A) 5  |  B) 7  |  C) 10  |  D) 12
16. In the sex-linked disease 'Colour Blindness', which colors can a person not distinguish?
    A) Yellow and Blue  |  B) Red and Green  |  C) White and Black  |  D) All colors
17. Who coined the term 'Gene'?
    A) Mendel  |  B) Johannsen  |  C) Morgan  |  D) Bateson
18. The passing of traits from parents to offspring is called?
    A) Variation  |  B) Heredity  |  C) Evolution  |  D) Adaptation
19. Chromosome number in Klinefelter's Syndrome is?
    A) 45  |  B) 46  |  C) 47 (44+XXY)  |  D) 48
20. A dominant trait is one that:
    A) Appears in F1 generation  |  B) Is hidden in F1  |  C) Never appears  |  D) Only appears in F2
21. Assertion (A): Blood group 'O' is the Universal Donor in humans. Reason (R): Red blood cells of group 'O' have no antigen on them.
    A) Both A and R are true, R is correct explanation  |  B) Both A and R are true, R is not correct explanation  |  C) A is true, R is false  |  D) A is false, R is true
22. Example of Incomplete Dominance is found in which plant?
    A) Pea  |  B) Snapdragon (Antirrhinum)  |  C) Potato  |  D) Wheat
23. Dihybrid cross phenotype ratio 9:3:3:1 confirms which law?
    A) Law of Segregation  |  B) Independent Assortment  |  C) Dominance  |  D) Co-dominance
24. Best example of Co-dominance is?
    A) Pea seeds  |  B) ABO blood group  |  C) Skin color  |  D) Haemophilia
25. What is a Test cross used for?
    A) To find unknown genotype  |  B) For breed improvement  |  C) For variation  |  D) None
26. Who discovered Linkage?
    A) Mendel  |  B) T.H. Morgan  |  C) Sutton  |  D) Boveri
27. Recombination frequency depends on?
    A) Distance between genes  |  B) Age of plant  |  C) Light  |  D) Temperature
28. Assertion (A): Haemophilia is more common in males. Reason (R): It is an X-linked recessive disorder and males have only one X chromosome.
    A) Both A and R are true, R is correct explanation  |  B) Both A and R are true, R is not correct explanation  |  C) A is true, R is false  |  D) Both false
29. Example of Polygenic inheritance is?
    A) Pea size  |  B) Human skin color  |  C) ABO blood group  |  D) Flower color
30. Who developed the Punnett Square?
    A) Mendel  |  B) Reginald Punnett  |  C) Morgan  |  D) Sutton
31. What is the purpose of a Reciprocal cross?
    A) To test effect of sex  |  B) To see dominance  |  C) To know genotype  |  D) To test purity
32. In pea plants, 'Axial flower' is what type of trait?
    A) Dominant  |  B) Recessive  |  C) Co-dominant  |  D) Intermediate
33. A single gene controlling more than one trait is called?
    A) Linkage  |  B) Pleiotropy  |  C) Epistasis  |  D) Mutation
34. In Pedigree analysis, what does a Square symbol represent?
    A) Female  |  B) Male  |  C) Unspecified sex  |  D) Affected offspring
35. Main reason Mendel's work remained neglected was?
    A) Lack of communication  |  B) Use of mathematics  |  C) Concept of stable factors (genes)  |  D) All of the above
36. Who worked on the structure 'Drosophila'?
    A) Mendel  |  B) Morgan  |  C) Bridges  |  D) de Vries
37. Who were the rediscoverers of Mendel's laws?
    A) de Vries, Correns and Tschermak  |  B) Watson and Crick  |  C) Sutton and Boveri  |  D) None
38. Example of Point mutation is?
    A) Thalassemia  |  B) Sickle-cell anaemia  |  C) Down's syndrome  |  D) AIDS
39. How are male bees (Drones) produced?
    A) By fertilization  |  B) By Parthenogenesis  |  C) By fusion  |  D) By division
40. Who coined the term 'Mutation'?
    A) Mendel  |  B) Hugo de Vries  |  C) Morgan  |  D) Lamarck
41. If a colour blind man marries a normal (but carrier) woman, what percentage of sons will be colour blind?
    A) 0%  |  B) 25%  |  C) 50%  |  D) 100%
42. How many types of genotypes are possible in the ABO blood group system?
    A) 3  |  B) 4  |  C) 6  |  D) 8
43. In Sickle-cell anaemia, what change occurs at the 6th position of the beta chain of haemoglobin?
    A) Valine instead of Glutamic acid  |  B) Glutamic acid instead of Valine  |  C) Lysine instead of Valine  |  D) None
44. What is the type of sex determination in birds?
    A) XX-XY  |  B) ZZ-ZW  |  C) XX-XO  |  D) Haplo-diploid
45. To which genes does Mendel's 'Law of Independent Assortment' NOT apply?
    A) Genes far apart  |  B) Linked genes  |  C) Genes on different chromosomes  |  D) None
46. Which enzyme is deficient in Phenylketonuria (PKU)?
    A) Phenylalanine hydroxylase  |  B) Tyrosinase  |  C) Insulin  |  D) Polymerase
47. What is the issue in Thalassemia?
    A) Change in RBC shape  |  B) Reduced synthesis of globin chain  |  C) Failure of blood clotting  |  D) Lack of WBCs
48. Genotype ratio of F2 generation in a Monohybrid cross is?
    A) 3:1  |  B) 1:2:1  |  C) 9:3:3:1  |  D) 1:1
49. Who discovered 'X-Body' (later X-chromosome) in humans?
    A) Mendel  |  B) Henking  |  C) Sutton  |  D) Morgan
50. Where can Multiple alleles be studied?
    A) In an individual  |  B) In a Population  |  C) In F1 generation  |  D) In lab
51. Change in the number of chromosomes (e.g., 2n+1) is called?
    A) Polyploidy  |  B) Aneuploidy  |  C) Mutation  |  D) Inversion
52. Physical characteristics of a woman with Turner's Syndrome are?
    A) Sterility  |  B) Rudimentary ovaries  |  C) Short stature  |  D) All of the above
53. In pea plants, 'Green pods' are what type of trait?
    A) Dominant  |  B) Recessive  |  C) Co-dominant  |  D) None
54. If the whole set of chromosomes increases (e.g., 3n), it is called?
    A) Aneuploidy  |  B) Polyploidy  |  C) Trisomy  |  D) Monosomy
55. Genotype of a carrier woman for Haemophilia would be?
    A) XX  |  B) XhXh  |  C) XXh  |  D) XY
56. In which stage of meiosis does Crossing over occur?
    A) Leptotene  |  B) Zygotene  |  C) Pachytene  |  D) Diplotene
57. In which organism is the 'Haplo-diploid' mechanism of sex determination found?
    A) Human  |  B) Bird  |  C) Honey bee  |  D) Grasshopper
58. When did Mendel conduct his experiments?
    A) 1856-1863  |  B) 1842-1850  |  C) 1865-1870  |  D) 1900-1905
59. In Overdominance, the trait of the heterozygote is?
    A) Better than both homozygotes  |  B) Similar to one  |  C) Intermediate  |  D) None
60. Which genetic disorder is NOT a 'Mendelian disorder'?
    A) Haemophilia  |  B) Sickle cell anaemia  |  C) Down's syndrome  |  D) Cystic fibrosis