1. What is heredity?
a) The process of creating DNA
b) The transmission of traits from one generation to the next
c) The study of living organisms
d) The process of asexual reproduction
Answer: b

2. What leads to variations in sexually reproducing organisms?
a) Environmental factors
b) DNA copying errors
c) Independent inheritance of traits
d) All of the above
Answer: d

3. What did Mendel study to determine the laws of inheritance?
a) Pea plants
b) Corn plants
c) Bacteria
d) Human cells
Answer: a

4. What is a dominant trait?
a) A trait expressed only when both alleles are identical
b) A trait that is always expressed
c) A trait expressed only in the presence of recessive alleles
d) A trait that skips generations
Answer: b

5. What ratio did Mendel find in the F2 generation of a monohybrid cross?
a) 3:1
b) 1:1
c) 1:2:1
d) 9:3:3:1
Answer: a

6. Which characteristic of pea plants was not studied by Mendel?
a) Plant height
b) Seed shape
c) Flower color
d) Root length
Answer: d

7. What is a recessive trait?
a) A trait that appears in every generation
b) A trait masked in the presence of a dominant allele
c) A trait influenced by the environment
d) A trait that is always expressed
Answer: b

8. What is the term for a unit of inheritance?
a) Chromosome
b) DNA
c) Gene
d) Protein
Answer: c

9. How many pairs of chromosomes are present in human beings?
a) 23
b) 46
c) 22
d) 24
Answer: a

10. What do sex chromosomes determine in humans?
a) Height
b) Blood type
c) Gender
d) Skin color
Answer: c11. What is the genotype of a tall pea plant if its progeny includes short plants?

a) TT
b) Tt
c) tt
d) TTTT
Answer: b

12. What is the phenotype of a plant with the genotype Tt?
a) Short
b) Medium
c) Tall
d) Cannot determine
Answer: c

13. What does the term “homozygous” mean?
a) Having two identical alleles for a trait
b) Having two different alleles for a trait
c) Carrying no alleles for a trait
d) Having one dominant and one recessive allele
Answer: a

14. What does the term “heterozygous” mean?
a) Having two identical alleles for a trait
b) Having two different alleles for a trait
c) Having no alleles for a trait
d) Carrying only recessive alleles
Answer: b

15. Which part of the cell contains chromosomes?
a) Cytoplasm
b) Mitochondria
c) Nucleus
d) Cell membrane
Answer: c

16. What ratio is observed in the F2 generation of a dihybrid cross?
a) 3:1
b) 1:2:1
c) 9:3:3:1
d) 1:1
Answer: c

17. What is independent assortment?
a) Genes for different traits are inherited together.
b) Genes for different traits segregate independently.
c) Genes for the same trait segregate independently.
d) Genes are inherited randomly.
Answer: b

18. How is the sex of a child determined in humans?
a) By the mother’s chromosomes
b) By the father’s chromosomes
c) By environmental factors
d) By random chance
Answer: b

19. What is the genotype of a woman?
a) XY
b) XX
c) YY
d) None of these
Answer: b

20. What is the genotype of a man?
a) XY
b) XX
c) YY
d) None of these
Answer: a21. Which chromosome is responsible for maleness in humans?

a) X
b) Y
c) Both X and Y
d) Neither X nor Y
Answer: b

22. What is the mechanism of sex determination in humans?
a) Temperature-dependent
b) Genetic
c) Hormonal
d) Environmental
Answer: b

23. What is a genetic mutation?
a) A change in the structure of a chromosome
b) A change in the DNA sequence
c) A change in protein structure
d) A change in the phenotype only
Answer: b

24. What is the genetic makeup of gametes?
a) Diploid
b) Haploid
c) Triploid
d) Tetraploid
Answer: b

25. Which process ensures genetic diversity during reproduction?
a) DNA replication
b) Fertilization
c) Independent assortment
d) Both b and c
Answer: d

26. What do we inherit from our parents?
a) Proteins
b) Genes
c) Chromosomes only
d) Enzymes
Answer: b

27. What is the primary function of DNA?
a) Provide energy to the cell
b) Store genetic information
c) Produce hormones
d) Control cell division
Answer: b

28. What does Mendel’s law of segregation state?
a) Genes are inherited together.
b) Alleles segregate independently during gamete formation.
c) Chromosomes assort independently.
d) Traits are influenced by the environment.
Answer: b

29. Which trait is expressed in a heterozygous individual?
a) Recessive
b) Dominant
c) Both traits equally
d) No trait is expressed
Answer: b

30. What are alleles?
a) Genes on different chromosomes
b) Alternate forms of a gene
c) Chromosomes that determine sex
d) Sections of a protein
Answer: b

31. How many chromosomes are present in human gametes?
a) 46
b) 44
c) 23
d) 22
Answer: c

32. What kind of trait is blood group inheritance an example of?
a) Simple dominance
b) Codominance
c) Recessive inheritance
d) Sex-linked inheritance
Answer: b

33. Why did Mendel choose pea plants for his experiments?
a) They grow quickly and reproduce sexually.
b) They show clear contrasting traits.
c) They can self-pollinate and cross-pollinate.
d) All of the above.
Answer: d

34. How does temperature influence sex determination in some reptiles?
a) Higher temperatures produce males.
b) Higher temperatures produce females.
c) It is random.
d) It has no influence.
Answer: b

35. What is a sex-linked trait?
a) A trait determined by autosomes
b) A trait determined by genes on sex chromosomes
c) A dominant trait
d) A trait inherited independently of sex
Answer: b

36. How do sex-linked traits affect males?
a) They are carriers of the trait.
b) They are less affected than females.
c) They are more affected as they have one X chromosome.
d) They are equally affected as females.
Answer: c

37. What are homologous chromosomes?
a) Chromosomes inherited from the same parent
b) Chromosomes that carry the same genes
c) Chromosomes that determine sex
d) Chromosomes that do not pair
Answer: b

38. What is crossing over?
a) A process that separates chromosomes during meiosis
b) Exchange of genetic material between homologous chromosomes
c) Transfer of DNA from parents to offspring
d) A mutation in chromosomes
Answer: b

39. Which type of inheritance shows blending of traits?
a) Codominance
b) Incomplete dominance
c) Sex-linked inheritance
d) Simple dominance
Answer: b

40. What is a genetic carrier?
a) An individual with two dominant alleles
b) An individual with one recessive allele for a trait
c) An individual with two recessive alleles
d) An individual who cannot inherit traits
Answer: b

41. What is the shape of DNA?
a) Double helix
b) Circular
c) Single strand
d) Linear chain
Answer: a

42. What is a Punnett square used for?
a) Calculating genetic diversity
b) Predicting offspring traits
c) Determining DNA structure
d) Identifying mutations
Answer: b

43. What determines the ABO blood group system?
a) Hemoglobin levels
b) Genes and antigens on red blood cells
c) Oxygen-carrying capacity
d) Immune system strength
Answer: b

44. What are sex chromosomes?
a) Chromosomes that determine traits
b) Chromosomes that determine gender
c) Chromosomes that control protein synthesis
d) Chromosomes present only in males
Answer: b

45. How do dominant and recessive traits differ?
a) Dominant traits mask recessive ones.
b) Recessive traits mask dominant ones.
c) They are expressed equally.
d) Both are expressed in heterozygous individuals.
Answer: a

46. What are gametes?
a) Body cells
b) Reproductive cells
c) Cells without DNA
d) Cells with identical traits
Answer: b

47. What is the purpose of meiosis?
a) Produce identical body cells
b) Generate gametes with half the chromosome number
c) Repair damaged DNA
d) Ensure mutations occur
Answer: b

48. What is DNA made of?
a) Proteins
b) Nucleotides
c) Lipids
d) Carbohydrates
Answer: b

49. What ensures genetic stability across generations?
a) DNA replication
b) Gamete fusion
c) Chromosome pairing
d) All of the above
Answer: d

50. Why are variations important in evolution?
a) They increase adaptability to changing environments.
b) They ensure identical offspring.
c) They slow reproduction.
d) They prevent survival.
Answer: a51. What are autosomes?

a) Chromosomes that determine sex
b) Chromosomes that do not determine sex
c) Mitochondrial DNA
d) Proteins found in the nucleus
Answer: b

52. Which chromosome pair determines gender in humans?
a) Pair 21
b) Pair 22
c) Pair 23
d) Pair 24
Answer: c

53. What are the chances of a child being male or female?
a) 75% male, 25% female
b) 50% male, 50% female
c) 25% male, 75% female
d) 100% male
Answer: b

54. What did Mendel’s experiments prove about inheritance?
a) Traits are inherited randomly.
b) Traits follow specific patterns.
c) Traits are only inherited from the father.
d) Traits skip every alternate generation.
Answer: b

55. How are traits expressed in organisms?
a) Through proteins coded by genes
b) Through environmental changes
c) Through RNA duplication
d) By random cell division
Answer: a

56. What are the building blocks of DNA?
a) Sugars
b) Proteins
c) Nucleotides
d) Lipids
Answer: c

57. What is the role of chromosomes in heredity?
a) Store and transfer genetic information
b) Produce hormones
c) Control the immune system
d) Aid in cell division
Answer: a

58. What causes variations in sexually reproducing organisms?
a) DNA copying errors
b) Genetic recombination
c) Environmental changes
d) All of the above
Answer: d

59. What is the term for alternative forms of a gene?
a) Traits
b) Alleles
c) Chromatids
d) Codons
Answer: b

60. What does the term “phenotype” refer to?
a) The genetic makeup of an organism
b) The physical appearance of a trait
c) The number of chromosomes in a cell
d) The sequence of DNA in a gene
Answer: b

61. What does “genotype” refer to?
a) The observable characteristics of an organism
b) The genetic makeup of an organism
c) The environmental influence on a trait
d) The process of cell division
Answer: b

62. How is codominance different from simple dominance?
a) Both alleles are expressed equally.
b) Only one allele is expressed.
c) Traits blend together.
d) One allele is suppressed.
Answer: a

63. What did Mendel observe in a dihybrid cross?
a) Traits are inherited independently.
b) Traits are always inherited together.
c) Traits skip generations.
d) Traits are influenced by environmental factors.
Answer: a

64. Which is an example of codominance?
a) Pink flowers from red and white parents
b) A red and white spotted flower
c) Only red flowers from a red and white cross
d) All white flowers
Answer: b

65. What is the purpose of a test cross?
a) To identify the dominant allele
b) To determine the genotype of an organism
c) To observe mutations
d) To produce hybrids
Answer: b

66. What is the result of meiosis?
a) Four identical cells
b) Two identical cells
c) Four genetically diverse gametes
d) Two genetically diverse gametes
Answer: c

67. What is a recessive trait?
a) A trait that is always expressed
b) A trait expressed only when both alleles are recessive
c) A trait expressed in the presence of a dominant allele
d) A trait expressed in heterozygous individuals
Answer: b

68. Why is DNA replication important?
a) It helps in protein synthesis.
b) It ensures genetic material is passed on.
c) It repairs damaged cells.
d) It controls environmental adaptations.
Answer: b

69. What does a pedigree chart show?
a) Genetic inheritance across generations
b) Chromosome structure
c) Gene mutation patterns
d) Environmental influences on traits
Answer: a

70. Which is an example of incomplete dominance?
a) Pink flowers from red and white parents
b) Red and white flowers from the same cross
c) Only red flowers
d) Only white flowers
Answer: a

71. What is a dihybrid cross?
a) A cross involving two traits
b) A cross involving a single trait
c) A test for mutations
d) A cross between different species
Answer: a

72. How many chromosomes are in a human somatic cell?
a) 23
b) 44
c) 46
d) 48
Answer: c

73. How does fertilization restore chromosome number?
a) By combining two haploid gametes
b) By reducing chromosome number
c) By creating mutations
d) By destroying one gamete’s DNA
Answer: a

74. What ensures independent assortment?
a) Crossing over
b) Segregation of chromosomes
c) Random alignment during meiosis
d) All of the above
Answer: d

75. Which type of cell division produces gametes?
a) Mitosis
b) Meiosis
c) Binary fission
d) Budding
Answer: b

76. How do dominant traits appear in offspring?
a) Only in heterozygous individuals
b) Only in homozygous individuals
c) In both heterozygous and homozygous individuals
d) Never in heterozygous individuals
Answer: c

77. What controls inheritance patterns?
a) Chromosomes and alleles
b) Cytoplasm
c) Environmental conditions
d) Random mutations
Answer: a

78. What is the relationship between genes and proteins?
a) Genes are made of proteins.
b) Proteins determine the sequence of genes.
c) Genes code for proteins.
d) Proteins and genes are unrelated.
Answer: c

79. What determines the ABO blood group system?
a) Hemoglobin levels
b) Antigens on red blood cells
c) DNA sequences in white blood cells
d) Enzyme levels in the plasma
Answer: b

80. What is the role of chromosomes during fertilization?
a) Determine phenotypes
b) Ensure equal genetic contribution from parents
c) Control mutations
d) Create new genes
Answer: b

81. What results in genetic diversity during reproduction?
a) DNA replication
b) Random fertilization
c) Crossing over
d) Both b and c
Answer: d

82. Why do gametes have half the chromosome number?
a) To prevent mutations
b) To restore the chromosome number during fertilization
c) To maintain diversity
d) To allow mitosis
Answer: b

83. How does sex-linked inheritance work?
a) Genes are carried on autosomes.
b) Genes are carried on sex chromosomes.
c) Traits are inherited independently of gender.
d) Genes are found in mitochondrial DNA.
Answer: b

84. What ensures the stability of genetic material across generations?
a) Accurate DNA replication
b) Meiosis
c) Fertilization
d) All of the above
Answer: d

85. What determines the sex of a child?
a) Maternal chromosomes only
b) Paternal chromosomes
c) Environmental conditions
d) Mutation during meiosis
Answer: b

86. What is Mendel’s first law of inheritance?
a) Law of independent assortment
b) Law of segregation
c) Law of codominance
d) Law of incomplete dominance
Answer: b

87. What is a hybrid organism?
a) An organism with identical alleles
b) An organism with two different alleles for a trait
c) An organism with no dominant traits
d) An organism that reproduces asexually
Answer: b

88. How does sexual reproduction create variation?
a) By combining genetic material from two parents
b) By duplicating identical genes
c) By eliminating recessive traits
d) By producing identical offspring
Answer: a

89. What is the role of the Y chromosome in humans?
a) Determines female traits
b) Determines male traits
c) Determines autosomal traits
d) Has no role in inheritance
Answer: b

90. What is the purpose of Mendel’s experiments?
a) To study evolution
b) To understand genetic inheritance
c) To identify mutations
d) To study environmental effects on traits
Answer: b

91. What are homologous chromosomes?
a) Chromosomes inherited from one parent
b) Chromosomes that carry the same genes in the same order
c) Chromosomes responsible for sex determination
d) Randomly assorted chromosomes
Answer: b

92. What is a karyotype?
a) The study of genetic diversity
b) The arrangement of all chromosomes in a cell
c) A pedigree chart for traits
d) The structure of DNA molecules
Answer: b

93. What are linked traits?
a) Traits controlled by the same gene
b) Traits influenced by environmental factors
c) Traits inherited together due to proximity on a chromosome
d) Traits found on different chromosomes
Answer: c

94. How do X-linked traits affect males?
a) They are more likely to express recessive traits.
b) They are carriers of recessive traits.
c) They have no effect on males.
d) They are less likely to express traits than females.
Answer: a

95. What is a polygenic trait?
a) A trait controlled by multiple genes
b) A trait controlled by a single gene
c) A trait inherited from the mother only
d) A trait determined by sex chromosomes
Answer: a

96. What determines the inheritance of traits?
a) DNA mutations
b) Chromosomes and genes
c) Environmental factors only
d) Protein synthesis
Answer: b

97. What is the purpose of fertilization?
a) To restore diploid chromosome number
b) To produce gametes
c) To ensure mutations occur
d) To eliminate recessive alleles
Answer: a

98. What is a monohybrid cross?
a) A cross involving two traits
b) A cross involving one trait
c) A cross between different species
d) A cross involving no traits
Answer: b

99. What happens during crossing over?
a) Chromosomes duplicate identically
b) Genetic material is exchanged between homologous chromosomes
c) Chromosomes are destroyed
d) Mutations occur randomly
Answer: b

100. Why are Mendel’s laws important?
a) They explain patterns of inheritance.
b) They identify genetic mutations.
c) They eliminate recessive traits.
d) They determine protein synthesis.
Answer: a