1. Who is known as the “Father of Genetics”?
A) Charles Darwin
B) Gregor Mendel
C) Thomas Hunt Morgan
D) Watson and Crick
Answer: B
Explanation: Mendel, through his experiments on pea plants (Pisum sativum), formulated the laws of inheritance. He is called the Father of Genetics.
2. Mendel conducted experiments on ____________.
A) Maize
B) Pea (Pisum sativum)
C) Wheat
D) Sunflower
Answer: B
Explanation: Mendel selected pea plants because they had contrasting characters, short generation time, could self-pollinate, and allowed controlled cross-pollination.
3. Mendel studied inheritance of traits using ____________.
A) Hybridization
B) Pure line breeding
C) Controlled pollination
D) All of these
Answer: D
Explanation: Mendel used true-breeding plants, hybridization experiments, and carefully controlled pollination to study inheritance.
4. The law of segregation is also known as ____________.
A) Law of purity of gametes
B) Law of dominance
C) Law of independent assortment
D) Law of blending inheritance
Answer: A
Explanation: It states that alleles segregate during gamete formation and each gamete receives only one allele of a pair.
5. Which Mendelian law explains independent inheritance of traits?
A) Law of dominance
B) Law of segregation
C) Law of independent assortment
D) Law of blending
Answer: C
Explanation: Traits assort independently because alleles of different genes are distributed into gametes randomly.
6. The phenotypic ratio in monohybrid cross (F2 generation) is ____________.
A) 3:1
B) 1:2:1
C) 9:3:3:1
D) 2:1
Answer: A
Explanation: In a cross like Tt × Tt, 3 plants are tall and 1 dwarf, giving 3:1 ratio.
7. The genotypic ratio in monohybrid cross (F2 generation) is ____________.
A) 3:1
B) 1:2:1
C) 9:3:3:1
D) 1:1
Answer: B
Explanation: Genotypes are TT : Tt : tt in ratio 1:2:1.
8. The phenotypic ratio in a dihybrid cross (F2 generation) is ____________.
A) 9:3:3:1
B) 1:2:1
C) 3:1
D) 2:1
Answer: A
Explanation: Crossing RrYy × RrYy produces 9 round yellow, 3 round green, 3 wrinkled yellow, 1 wrinkled green.
9. The parental generation (P) in Mendel’s experiments were ____________.
A) Hybrid plants
B) True-breeding plants
C) Mutants
D) Wild varieties
Answer: B
Explanation: Mendel used homozygous plants that consistently produced the same traits.
10. Crossing tall (TT) with dwarf (tt) gives all tall progeny (Tt). This shows ____________.
A) Segregation
B) Dominance
C) Recessiveness
D) Independent assortment
Answer: B
Explanation: The tall allele (T) masks dwarf allele (t), proving dominance.
11. When both alleles express equally in heterozygote, it is ____________.
A) Dominance
B) Codominance
C) Recessiveness
D) Epistasis
Answer: B
Explanation: In codominance, both alleles are expressed (e.g., blood group IAIB shows both A and B antigens).
12. Incomplete dominance was first reported in ____________.
A) Pea
B) Four o’clock plant (Mirabilis jalapa)
C) Maize
D) Wheat
Answer: B
Explanation: Red (RR) × White (rr) give Pink (Rr) in F1, showing blending of traits.
13. Test cross involves ____________.
A) Crossing F1 with dominant parent
B) Crossing F1 with recessive parent
C) Crossing two F1 individuals
D) Crossing two recessive parents
Answer: B
Explanation: Test cross is used to determine whether a plant with dominant phenotype is homozygous or heterozygous.
14. The ratio obtained in test cross of dihybrid (AaBb × aabb) ____________.
A) 9:3:3:1
B) 1:2:1
C) 1:1:1:1
D) 3:1
Answer: C
Explanation: Each gamete combination results in equal proportion of four phenotypes.
15. Alleles are ____________.
A) Different forms of a gene
B) Different forms of a chromosome
C) Homologous chromosomes
D) Non-coding DNA
Answer: A
Explanation: Alleles represent variants of a gene located at the same locus on homologous chromosomes.
16. If heterozygous tall pea plant (Tt) is selfed, probability of dwarf offspring is ____________.
A) 0%
B) 25%
C) 50%
D) 75%
Answer: B
Explanation: Cross Tt × Tt gives TT, Tt, Tt, tt → 1/4 are dwarf (tt).
17. A homozygous tall (TT) crossed with heterozygous tall (Tt) gives ratio ____________.
A) 1 TT : 1 Tt
B) 3 Tall : 1 Dwarf
C) 1:2:1
D) All tall
Answer: A
Explanation: Gametes: TT × Tt → TT and Tt, all tall but genotypic ratio 1:1.
18. Dominant traits studied by Mendel included ____________.
A) Tall stem, round seed, yellow seed
B) Dwarf stem, wrinkled seed, green seed
C) Red flower, white seed
D) Green pod, terminal flower
Answer: A
Explanation: These were among Mendel’s seven dominant traits in pea.
19. Crossing Aa × Aa produces heterozygotes in what proportion?
A) 25%
B) 50%
C) 75%
D) 100%
Answer: B
Explanation: Cross Aa × Aa → 25% AA, 50% Aa, 25% aa. Thus, heterozygotes = 50%.
20. Independent assortment occurs because of ____________.
A) Crossing over
B) Random orientation of homologous chromosomes
C) Mutation
D) Gene duplication
Answer: B
Explanation: During metaphase I of meiosis, chromosomes align randomly leading to assortment of alleles.
21. The physical location of a gene on a chromosome is ____________.
A) Allele
B) Genome
C) Locus
D) Codon
Answer: C
Explanation: A locus is the fixed position where a gene resides on a chromosome.
22. Which of the following is a monohybrid cross?
A) Aa × Aa
B) AaBb × AaBb
C) AaBb × aabb
D) TtRr × TtRr
Answer: A
Explanation: Monohybrid cross involves a single trait/gene, hence Aa × Aa.
23. Back cross means ____________.
A) Crossing F1 with F1
B) Crossing F1 with any parent
C) Crossing F1 with dominant parent only
D) Crossing F1 with recessive parent only
Answer: B
Explanation: A back cross can be with either dominant or recessive parent to check genotype or improve traits.
24. Example of recessive trait in Mendel’s pea ____________.
A) Tall stem
B) Round seed
C) Green seed
D) Yellow pod
Answer: C
Explanation: Green seed color was recessive, while yellow was dominant.
25. If both alleles are identical, the condition is ____________.
A) Heterozygous
B) Homozygous
C) Hybrid
D) Dominant
Answer: B
Explanation: Homozygous individuals have identical alleles (TT or tt).
26. When a single gene controls more than one trait, the phenomenon is called ____________.
A) Epistasis
B) Pleiotropy
C) Codominance
D) Polygenic inheritance
Answer: B
Explanation: In pleiotropy, one gene affects multiple traits. Example: sickle-cell anemia gene affects hemoglobin, RBC shape, and resistance to malaria.
27. Skin color in humans is an example of ____________.
A) Monogenic inheritance
B) Pleiotropy
C) Polygenic inheritance
D) Codominance
Answer: C
Explanation: Skin color is controlled by multiple genes, each adding a small effect (quantitative inheritance).
28. Interaction of two non-allelic genes where one masks the effect of another is called ____________.
A) Codominance
B) Incomplete dominance
C) Epistasis
D) Polygenic inheritance
Answer: C
Explanation: Example: Coat color in mice, where one gene masks expression of another.
29. The ABO blood group in humans shows ____________.
A) Dominance
B) Codominance and multiple alleles
C) Incomplete dominance
D) Epistasis
Answer: B
Explanation: IA and IB are codominant, i is recessive; thus, 3 alleles control ABO system.
30. Incomplete dominance results in ____________.
A) Blending of traits in heterozygote
B) Expression of both traits fully
C) Complete dominance
D) Suppression of traits
Answer: A
Explanation: Red × White flower in Mirabilis gives pink.
31. Example of codominance in humans is ____________.
A) Sickle-cell anemia
B) ABO blood group
C) Albinism
D) Cystic fibrosis
Answer: B
Explanation: Both IA and IB express equally in blood group AB.
32. Lethal alleles were first studied in ____________.
A) Mice
B) Pea
C) Maize
D) Drosophila
Answer: D
Explanation: Inheritance of yellow body color in Drosophila led to discovery of lethal alleles.
33. Which cross gives 9:7 phenotypic ratio?
A) Duplicate genes
B) Complementary genes
C) Codominance
D) Lethal genes
Answer: B
Explanation: Both genes are required for expression; absence of either masks the trait.
34. Which cross gives 15:1 phenotypic ratio?
A) Duplicate genes
B) Complementary genes
C) Epistasis
D) Codominance
Answer: A
Explanation: Either of two dominant genes can produce the trait.
35. Which cross gives 9:3:4 phenotypic ratio?
A) Recessive epistasis
B) Dominant epistasis
C) Codominance
D) Incomplete dominance
Answer: A
Explanation: Example: Coat color in mice.
36. Which cross gives 12:3:1 ratio?
A) Duplicate genes
B) Recessive epistasis
C) Dominant epistasis
D) Complementary genes
Answer: C
Explanation: Presence of one dominant allele masks expression of another gene.
37. Which cross gives 13:3 ratio?
A) Suppressor gene action
B) Recessive epistasis
C) Duplicate gene
D) Dominant epistasis
Answer: A
Explanation: One gene suppresses the effect of another.
38. Who discovered linkage?
A) Mendel
B) Morgan
C) Bateson and Punnett
D) Watson and Crick
Answer: C
Explanation: They observed deviation from 9:3:3:1 ratio in sweet pea (Lathyrus).
39. Who explained linkage using Drosophila?
A) Mendel
B) Thomas Hunt Morgan
C) Bateson
D) Darwin
Answer: B
Explanation: Morgan studied X-linked genes in Drosophila and explained linkage.
40. Linkage is ____________.
A) Independent assortment of genes
B) Tendency of genes to be inherited together
C) Random mutation
D) Codominance
Answer: B
Explanation: Genes close on the same chromosome are inherited together.
41. The strength of linkage between two genes depends on ____________.
A) Distance between genes on chromosome
B) Type of gametes
C) Type of dominance
D) DNA replication
Answer: A
Explanation: Closer genes show stronger linkage.
42. Crossing over occurs in ____________.
A) Mitosis
B) Prophase I of meiosis
C) Metaphase II
D) Anaphase I
Answer: B
Explanation: Homologous chromosomes exchange segments during pachytene.
43. The exchange of genetic material between non-sister chromatids is called ____________.
A) Mutation
B) Crossing over
C) Independent assortment
D) Recombination
Answer: B
Explanation: Crossing over is the physical process where homologous chromosomes (one from each parent) align and exchange segments of their DNA.
44. The unit of recombination frequency is ____________.
A) Centromere
B) Map unit (centimorgan)
C) Base pair
D) Chromatid
Answer: B
Explanation: 1% recombination = 1 centimorgan (cM).
45. Maximum recombination frequency possible between two genes is ____________.
A) 25%
B) 50%
C) 75%
D) 100%
Answer: B
Explanation: When genes are very far apart, they assort independently (like unlinked).
46. If two genes show 20% recombination, distance between them is ____________.
A) 2 cM
B) 20 cM
C) 50 cM
D) 200 cM
Answer: B
Explanation: The relationship between recombination frequency and genetic distance is measured in centimorgans (cM) or map units. By definition, $1\%$ recombination frequency is equal to 1 centimorgan (cM).
47. The first genetic map was prepared by ____________.
A) Mendel
B) Morgan
C) Sturtevant
D) Watson
Answer: C
Explanation: A student of Morgan, he mapped genes in Drosophila using recombination frequencies.
48. Coupling and repulsion hypothesis was given by ____________.
A) Bateson and Punnett
B) Morgan
C) Mendel
D) Sturtevant
Answer: A
Explanation: They observed linked genes inherited together (coupling) or separately (repulsion).
49. A test cross with linked genes shows ____________.
A) 9:3:3:1
B) 1:2:1
C) Deviation from Mendelian ratio
D) 3:1
Answer: C
Explanation: Linked genes do not assort independently.
50. Linkage reduces ____________.
A) Mutation
B) Independent assortment
C) Crossing over
D) Gene expression
Answer: B
Explanation: Genes located close together on the same chromosome tend to be inherited together.
51. The physical basis of heredity is ____________.
A) Genes
B) Chromosomes
C) DNA
D) Protein
Answer: B
Explanation: Chromosomes carry genes, the units of heredity. Sutton and Boveri (1902) proposed the chromosomal theory of inheritance.
52. Genes are located on ____________.
A) Centromere
B) Chromosomes
C) Ribosomes
D) Mitochondria only
Answer: B
Explanation: Genes are specific DNA sequences present at loci on chromosomes.
53. Who proposed the chromosomal theory of inheritance?
A) Mendel
B) Sutton and Boveri
C) Morgan
D) Watson and Crick
Answer: B
Explanation: They correlated Mendel’s factors with chromosomes.
54. In humans, the number of chromosomes is ____________.
A) 23
B) 46
C) 44
D) 48
Answer: B
Explanation: Humans have 23 pairs = 46 chromosomes (22 autosome pairs + 1 sex chromosome pair).
55. The term “linkage group” refers to ____________.
A) Chromosome
B) Gene cluster
C) Alleles
D) Genome
Answer: A
Explanation: Each chromosome carries one linkage group (all genes inherited together).
56. Mutation is ____________.
A) Change in phenotype only
B) Sudden heritable change in genetic material
C) Gene recombination
D) Environmental adaptation
Answer: B
Explanation: A mutation is a permanent alteration in the DNA sequence that makes up a gene.
57. Mutations that occur in gametes are called ____________.
A) Somatic mutations
B) Germinal mutations
C) Chromosomal aberrations
D) Induced mutations
Answer: B
Explanation: They are heritable and passed to offspring.
58. Mutations occurring in body cells are ____________.
A) Germinal mutations
B) Somatic mutations
C) Induced mutations
D) Chromosomal mutations
Answer: B
Explanation: Somatic mutations are not inherited by offspring.
59. Mutation in a single nucleotide is ____________.
A) Point mutation
B) Frameshift mutation
C) Chromosomal mutation
D) Polyploidy
Answer: A
Explanation: Example: Sickle cell anemia caused by substitution of A → T in HBB gene.
60. Sickle cell anemia is caused by substitution of ____________.
A) Glutamic acid → Valine
B) Valine → Glutamic acid
C) Glycine → Serine
D) Alanine → Glycine
Answer: A
Explanation: At 6th position of β-globin chain, glutamic acid is replaced by valine.
61. Frameshift mutation is caused by ____________.
A) Substitution of base
B) Addition or deletion of base
C) Inversion of segment
D) Duplication of gene
Answer: B
Explanation: Alters reading frame, changing all downstream codons.
62. A mutation that changes one codon to a stop codon is ____________.
A) Missense mutation
B) Nonsense mutation
C) Silent mutation
D) Neutral mutation
Answer: B
Explanation: Leads to premature termination of protein synthesis.
63. Down’s syndrome is caused by ____________.
A) Trisomy of chromosome 21
B) Monosomy of X
C) Trisomy of 18
D) Deletion of chromosome 5
Answer: A
Explanation: Down syndrome is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is the most common chromosomal anomaly in humans.
64. Turner’s syndrome is ____________.
A) 47, XXY
B) 45, XO
C) 47, XYY
D) 46, XY
Answer: B
Explanation: Females with single X chromosome, sterile.
65. Klinefelter’s syndrome is ____________.
A) 47, XXY
B) 45, XO
C) 47, XYY
D) 46, XY
Answer: A
Explanation: Males with extra X chromosome, show sterility and feminine characters.
66. Cri-du-chat syndrome results from ____________.
A) Trisomy of chromosome 18
B) Deletion of short arm of chromosome 5
C) Trisomy of chromosome 13
D) Translocation of chromosome 21
Answer: B
Explanation: Causes cat-like cry in infants.
67. Who discovered transformation in bacteria?
A) Griffith
B) Avery, MacLeod, McCarty
C) Hershey and Chase
D) Watson and Crick
Answer: A
Explanation: In 1928, Griffith showed transfer of genetic material in Streptococcus pneumoniae.
68. Avery, MacLeod and McCarty proved that the transforming principle was ____________.
A) Protein
B) RNA
C) DNA
D) Lipid
Answer: C
Explanation: While Frederick Griffith first discovered the “transforming principle” in 1928, it was the team of Oswald Avery, Colin MacLeod, and Maclyn McCarty in 1944 who provided the first definitive chemical evidence that DNA is the hereditary material.
69. Hershey and Chase experiment with bacteriophage showed ____________.
A) Protein is genetic material
B) DNA is genetic material
C) RNA is genetic material in all organisms
D) Chromosomes carry only proteins
Answer: B
Explanation: DNA (labelled with 32P) entered bacteria, proteins (labelled with 35S) did not.
70. In some viruses, genetic material is ____________.
A) DNA only
B) RNA only
C) Either DNA or RNA
D) Both DNA and RNA
Answer: C
Explanation: Viruses may have DNA (bacteriophages) or RNA (HIV, influenza).
71. The double helix model of DNA was proposed by ____________.
A) Hershey and Chase
B) Avery and MacLeod
C) Watson and Crick
D) Franklin and Wilkins
Answer: C
Explanation: In 1953, James Watson and Francis Crick published their groundbreaking paper in the journal Nature, proposing the double helix structure of DNA. For this discovery, they were awarded the Nobel Prize in Physiology or Medicine in 1962.
72. The base pairing rule of DNA was given by ____________.
A) Watson
B) Chargaff
C) Crick
D) Franklin
Answer: B
Explanation: A = T, G = C, purines equal pyrimidines.
73. In DNA, adenine pairs with thymine by ____________.
A) One H-bond
B) Two H-bonds
C) Three H-bonds
D) Covalent bond
Answer: B
Explanation: In the DNA double helix, the two strands are held together by hydrogen bonds between complementary nitrogenous bases. Specifically, Adenine (A) pairs with Thymine (T) using two hydrogen bonds.
74. In DNA, guanine pairs with cytosine by ____________.
A) One H-bond
B) Two H-bonds
C) Three H-bonds
D) Covalent bond
Answer: C
Explanation: In the double helix structure of DNA, nitrogenous bases from opposite strands pair up via hydrogen bonds. Specifically, Guanine (G) always pairs with Cytosine (C) using three hydrogen bonds.
75. The backbone of DNA is made up of ____________.
A) Nucleotide bases only
B) Sugar and phosphate
C) Ribose and uracil
D) Hydrogen bonds
Answer: B
Explanation: Deoxyribose sugars linked by phosphate groups form the backbone, while bases project inward.
76. The three stop codons are ____________.
A) AUG, UAA, UAG
B) UAA, UAG, UGA
C) AUG, UGA, UGG
D) UAA, UGA, GUG
Answer: B
Explanation: These codons do not code for amino acids and terminate protein synthesis.
77. The start codon for protein synthesis is ____________.
A) UAA
B) AUG
C) UGA
D) UAG
Answer: B
Explanation: AUG codes for methionine and serves as initiation codon.
78. The genetic code is ____________.
A) Ambiguous
B) Non-overlapping, nearly universal
C) Random
D) Different for each organism
Answer: B
Explanation: The same codons specify the same amino acids in almost all organisms.
79. Who proved that one gene codes for one enzyme?
A) Griffith
B) Beadle and Tatum
C) Watson and Crick
D) Mendel
Answer: B
Explanation: In Neurospora crassa, they showed “one gene–one enzyme” hypothesis.
80. The updated concept of Beadle and Tatum is ____________.
A) One gene–one protein
B) One gene–one polypeptide
C) One gene–one trait
D) One gene–many enzymes
Answer: B
Explanation: Some proteins consist of multiple polypeptide chains encoded by different genes.
81. The central dogma of molecular biology was given by ____________.
A) Watson
B) Crick
C) Mendel
D) Morgan
Answer: B
Explanation: Information flows DNA → RNA → Protein.
82. Transcription is the process of ____________.
A) RNA → DNA
B) DNA → RNA
C) RNA → Protein
D) DNA replication
Answer: B
Explanation: transcription is the first step of gene expression. It is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA).
83. Translation is the process of ____________.
A) RNA → DNA
B) DNA → RNA
C) RNA → Protein
D) DNA replication
Answer: C
Explanation: translation is the final step of gene expression where the information in messenger RNA (mRNA) is “decoded” to build a specific chain of amino acids, which then folds into a functional protein.
84. Enzyme involved in transcription ____________.
A) DNA polymerase
B) RNA polymerase
C) Ligase
D) Helicase
Answer: B
Explanation: RNA polymerase is the primary enzyme responsible for transcription. It “reads” a specific sequence of DNA and assembles a complementary strand of RNA.
85. Enzyme that removes supercoiling during DNA replication is ____________.
A) Helicase
B) Topoisomerase (gyrase)
C) Primase
D) Ligase
Answer: B
Explanation: During DNA replication, as the helicase enzyme unwinds the double helix, the DNA ahead of the replication fork becomes tightly twisted and overwound. This physical tension is known as supercoiling.
86. Okazaki fragments are formed during ____________.
A) Transcription
B) Leading strand synthesis
C) Lagging strand synthesis
D) RNA splicing
Answer: C
Explanation: DNA polymerase works in 5′ → 3′ direction, producing fragments on lagging strand.
87. The functional unit of DNA carrying information for protein synthesis is ____________.
A) Chromosome
B) Gene
C) Codon
D) Nucleotide
Answer: B
Explanation: a gene is specifically defined as the functional unit of heredity and the segment of DNA that contains the specific instructions required to synthesize a protein (or a functional RNA molecule).
88. Splicing in eukaryotes removes ____________.
A) Exons
B) Introns
C) Codons
D) mRNA cap
Answer: B
Explanation: Non-coding introns are removed, exons are joined.
89. In prokaryotes, transcription and translation are ____________.
A) Coupled (occur simultaneously)
B) Separate processes
C) Only transcription occurs
D) Only translation occurs
Answer: A
Explanation: In prokaryotes, transcription and translation happen in the same location (the cytoplasm) because these organisms lack a membrane-bound nucleus.
90. In eukaryotes, mRNA is first produced as ____________.
A) Mature mRNA
B) Pre-mRNA (hnRNA)
C) tRNA
D) rRNA
Answer: B
Explanation: In eukaryotes, the initial product of transcription is not immediately ready for protein synthesis. This “raw” transcript is called pre-mRNA or heterogeneous nuclear RNA (hnRNA).
91. The anticodon is found on ____________.
A) DNA
B) mRNA
C) tRNA
D) rRNA
Answer: C
Explanation: Anticodon base-pairs with mRNA codon during translation.
92. Ribosomes are sites of ____________.
A) DNA replication
B) RNA transcription
C) Protein synthesis
D) Mutation repair
Answer: C
Explanation: Ribosomes are the “factories” of the cell. Their primary job is to read the instructions provided by mRNA and assemble amino acids into a polypeptide chain, which then folds into a functional protein. This specific process is known as translation.
93. The first genetic material was likely ____________.
A) DNA
B) RNA
C) Protein
D) Lipid
Answer: B
Explanation: RNA world hypothesis suggests RNA acted as both genetic material and catalyst.
94. Who discovered transposons (jumping genes)?
A) Mendel
B) Barbara McClintock
C) Morgan
D) Griffith
Answer: B
Explanation: Barbara McClintock discovered transposons, often called “jumping genes,” through her pioneering work on maize (corn) in the 1940s and 1950s.
95. VNTRs (Variable Number Tandem Repeats) are used in ____________.
A) Protein synthesis
B) DNA fingerprinting
C) Mutation repair
D) RNA editing
Answer: B
Explanation: VNTRs (Variable Number Tandem Repeats) are short nucleotide sequences that are organized as tandem repeats.
96. Human genome has approximately ____________.
A) 1,000 genes
B) 20,000–25,000 genes
C) 1 million genes
D) 46 genes
Answer: B
Explanation: When the Human Genome Project (HGP) was first launched, scientists expected to find over 100,000 genes. However, when the project was completed in 2003, the scientific community was surprised to find that humans only have about 20,000 to 25,000 protein-coding genes.
97. Human Genome Project was completed in ____________.
A) 1995
B) 2003
C) 2010
D) 1985
Answer: B
Explanation: The Human Genome Project (HGP) was an international, publicly funded scientific research project that began in 1990. It was declared complete on April 14, 2003, remarkably finishing two years ahead of its original 15-year schedule.
98. A child with blood group O cannot have parents with ____________.
A) A and B
B) A and O
C) B and O
D) AB and O
Answer: D
Explanation: O group (ii) requires both parents to contribute i allele; AB parent cannot provide i.
99. Haemophilia is ____________.
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) Y-linked
Answer: C
Explanation: Males suffer more, females are usually carriers.
100. Color blindness is:
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) Y-linked
Answer: C
Explanation: The gene is on the X chromosome; more common in males.