Topic 1: MENDEL’S LAWS OF INHERITANCE
Q 1: Study of inheritance, heredity and variation of characters is called ………….
✅ Genetics
Q 2: Who is the Father of Genetics?
✅ Gregor Mendel
Q 3: Transmission of characters from parents to progeny is called ………….
✅ Inheritance
Q 4: Difference between parents and offspring is called
✅ Variation
Q 5: Mendel conducted some hybridization experiments on
✅ Garden peas (Pisum sativum)
Q 6: Removal of anthers of one plant to avoid self-pollination is called
✅ Emasculation
Q 7: Mendel selected …… pairs of true breeding pea varieties.
✅ 7
Q 8: Which of the following is a recessive trait?
Tall stem, Yellow pod, Round seed, Axial flower.
✅ Yellow pod
Q 9: A cross involving 2 plants differing in one character pair is called
✅ Monohybrid cross
Q 10: Monohybrid phenotypic ratio is
✅ 3:1
Q 11: Monohybrid genotypic ratio is
✅ 1:2:1
Q 12: Alternative forms of a gene are called .........
✅ Allele
Q 13: The condition in which chromosome pair carries similar alleles of a gene is called
✅ Homozygous
Q 14: The condition in which chromosome pair carries dissimilar alleles of a gene is called
✅ Heterozygous
Q 15: The character which is expressed in heterozygous condition is ……………
✅ Dominant character
Q 16: The character which is suppressed in heterozygous condition is …………….
✅ Recessive character
Q 17: Physical expression of a character is called
✅ Phenotype
Q 18: Genetic constitution of a character is called
✅ Genotype
Q 19: A graphical representation to calculate probability of all genotypes of offspring in a genetic cross is called
✅ Punnett square
Q 20: Mendel called the things inherited from parents to offspring as factors. Now it is known as ………
✅ Genes
Q 21: Crossing of an organism with dominant phenotype to a recessive individual is called ……….
✅ Testcross
Q 22: Monohybrid test cross ratio is .........
✅ 1:1
Q 23: Mendel conducted ……... to determine F2 genotype.
✅ Test cross
Q 24: Test cross is used to find out the …………… of a character.
✅ Unknown genotype
Q 25: A cross between two parents differing in 2 pairs of contrasting characters is called
✅ Dihybrid cross
Q 26: Genotype of heterozygous round yellow is written as
✅ RrYy
Q 27: On observing the F2 of dihybrid cross, Mendel found that yellow and green colour segregated in a ……… ratio.
✅ 3:1
Q 28: Dihybrid Phenotypic ratio is
✅ 9:3:3:1
Q 29: Dihybrid genotypic ratio is
✅ 1:2:1:2:4:2:1:2:1
Q 30: According to the First Law (Law of Dominance), characters are controlled by discrete units called …………
✅ Factors
Q 31: During gamete formation, the factors (alleles) of a character pair present in parents segregate from each other such that a gamete receives only one of the 2 factors. This law is called ...........
✅ Law of Segregation (Mendel’s Second Law)
Q 32: Which Mendel’s law is based on the results of dihybrid crosses?
✅ Law of Independent Assortment (Mendel’s Third Law)
Q 33: When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters. This law is known as ...........
✅ Law of Independent Assortment
Topic 2: OTHER PATTERNS OF INHERITANCE
Q 34: An inheritance in which heterozygous offspring shows intermediate character between two parental characteristics is called
✅ Incomplete Dominance
Q 35: In snapdragon (dog flower or Antirrhinum), cross between homozygous red & white produces pink flowered plant. This is an example for
✅ Incomplete Dominance
Q 36: In ……………, phenotypic & genotypic ratios are same.
✅ Incomplete Dominance
Q 37: In incomplete dominance, phenotypic and genotypic ratios are
✅ 1: 2: 1
Q 38: In heterozygotes, Modified allele will be generally ............
✅ Recessive
Q 39: ………………. Is the inheritance in which both alleles of a gene are expressed in a hybrid.
✅ Co-dominance
Q 40: A classic example of codominance in genetics is the ............
✅ ABO blood group system
Q 41: ABO blood groups are controlled by the gene ..........
✅ I
Q 42: Genotypes of A group is either IA IA or …………
✅ IA i
Q 43: Genotype of AB group is always
✅ IA IB
Q 44: ii is the genotype of ………………
✅ O group
Q 45: In ABO system, …………. shows codominance
✅ IA IB
Q 46: When IA and IB are present together, they both express their own types of sugar antigens on RBC. This is due to ........
✅ Co-dominance
Q 47: The presence of more than two alleles of a gene to govern same character is called
✅ Multiple allelism
Q 48: For the gene of ABO blood grouping, there are ……... types of alleles.
✅ 3
Q 49: The inheritance in which some traits are controlled by several genes (multiple genes) is called
✅ Polygenic inheritance
Q 50: Human skin colour, human height etc. are examples of ……………. Inheritance.
✅ Polygenic
Q 51: In a ………….. trait, the phenotype reflects contribution of each allele, i.e., the effect of each allele is additive.
✅ Polygenic
Q 52: In human, the genotype of darkest skin colour is AABBCC and that of lightest skin colour is
✅ aabbcc
Q 53: A phenomenon in which a single gene exhibits multiple phenotypic expression is called
✅ Pleiotropy
Q 54: In heterozygous condition, starch grain size of pea plant is intermediate sized. So it is an example for ……….
✅ Incomplete dominance
Q 55: Phenylketonuria causes mental retardation, reduction in hair & skin pigmentation. So it is an example for ………
✅ Pleiotropy
Topic 3: CHROMOSOMAL THEORY, LINKAGE, RECOMBINATION
Q 56: In 1900, de Vries, Correns and …………. independently rediscovered Mendel’s results.
✅ von Tschermak
Q 57: Chromosomal Theory of Inheritance (1902) was proposed by .............
✅ Walter Sutton & Theodore Boveri
Q 58: ……………. united chromosomal segregation with Mendelian principles and called it the chromosomal theory of inheritance.
✅ Sutton
Q 59: ………………. proved chromosomal theory of inheritance using fruit flies (Drosophila melanogaster).
✅ Thomas Hunt Morgan
Q 60: The physical association of genes on a chromosome is called
✅ Linkage
Q 61: The generation of non-parental gene combinations is called
✅ Recombination
Q 62: The terms linkage and recombination were coined by
✅ Morgan
Q 63: Morgan carried out several dihybrid crosses in ………. to study sex-linked genes.
✅ Drosophila
Q 64: In Drosophila, genes of body colour, eye colour and wing size are located on the ………..
✅ X chromosome
Q 65: When two genes are situated on same chromosome, proportion of parental gene combinations will be much higher than the non-parental type. This is due to ……………….
✅ Linkage
Q 66: In Drosophila, genes of white eye & yellow body were very tightly linked and showed only ………. recombination.
✅ 1.3%
Q 67: In Drosophila, genes of white eye & miniature wing were loosely linked and showed ………… recombination.
✅ 37.2%
Q 68: …………. genes show low recombination.
✅ Tightly linked
Q 69: ………… used the recombination frequency between gene pairs for measuring the distance between genes and mapped their position on the chromosome.
✅ Alfred Sturtevant
Topic 4: SEX DETERMINATION
Q 70: The chromosomes that are involved in sex determination are called
✅ Sex chromosomes
Q 71: The chromosomes other than sex chromosomes are called
✅ Autosomes
Q 72: In 1891, ………….. studied spermatogenesis in some insects and observed that 50 % of sperm received a nuclear structure after spermatogenesis, and other 50 % sperm did not receive it.
✅ Henking
Q 73: Who discovered X chromosome?
✅ Henking
Q 74: Sex determination mechanism of insects such as grasshopper is …………….
✅ XX-XO mechanism
Q 75: In which sex determination system, the number of chromosomes in the male and female are not equal?
✅ XX-XO
Q 76: Sex determination mechanism of Human and Drosophila is …………….
✅ XX-XY mechanism
Q 77: The sex determination mechanism of birds is ..........
✅ ZZ-ZW
Q 78: In birds sex determination system, female is represented as ..........
✅ ZW
Q 79: In which sex determination mechanism, male shows homogamety and female shows heterogamety?
✅ ZZ-ZW mechanism
Q 80: During spermatogenesis, males produce 2 types of gametes: 50 % with X-chromosome and 50 % with …………
✅ Y-chromosome
Q 81: In XX-XY system, the ………. determines whether the offspring male or female.
✅ Sperm
Q 82: Sex determination in …………. is based on the number of sets of chromosomes an individual receives.
✅ Honeybee
Q 83: In honeybee, an unfertilised egg develops as a male (drone). It is called …………….
✅ Parthenogenesis
Q 84: In honeybee, females are diploid (32 chromosomes) and males are haploid (16 chromosomes). This is called as ………. sex determination system.
✅ Haplodiploid
Q 85: In Haplodiploid sex determination system, the males produce sperms by ……….
✅ Mitosis
Topic 5: MUTATION, PEDIGREE ANALYSIS AND GENETIC DISORDERS
Q 86: The alteration of DNA sequences resulting in changes in the genotype and phenotype of an organism is called
✅ Mutation
Q 87: The change (substitution) in a single base pair of a DNA is called ……………
✅ Point mutation
Q 88: …………….. is an example for point mutation.
✅ Sickle cell anaemia
Q 89: The deletion or insertion of base pairs resulting in the shifting of DNA sequences is known as
✅ Frame-shift mutation
Q 90: The agents which induce mutation are called
✅ Mutagens
Q 91: An analysis of genetic history of traits in several generations of a family is called
✅ Pedigree analysis
Q 92: The representation or chart showing family history is called
✅ Family tree (pedigree)
Q 93: In pedigree analysis, affected female is represented as
✅ ⬤
Q 94: The symbol 🔲 is used to represent ………….
✅ Male
Q 95: In pedigree analysis, the symbol used for sex unspecified is
✅ ◇
Q 96: What is the symbol used in pedigree that shows consanguineous mating?
✅ 🔲=◯
Q 97: The disorders caused by alteration or mutation in the single gene are called
✅ Mendelian Disorders
Q 98: Which of the following is not a Mendelian disorder?
Sickle-cell anaemia, Down’s syndrome, Thalassemia, Cystic fibrosis.
✅ Down’s syndrome
Q 99: The pattern of inheritance of Mendelian disorders can be traced in a family by …………
✅ Pedigree analysis
Q 100: An example for the disease caused due to Autosomal dominant allele is
✅ Myotonic dystrophy
Q 101: A sex linked (X-linked) recessive disease, in which a protein involved in the blood clotting is affected is called ……………..
✅ Haemophilia
Q 102: In females, haemophilia is very rare because it happens only when mother is at least ………. and father haemophilic.
✅ Carrier
Q 103: Queen Victoria was a carrier of …………….
✅ Hemophilia
Q 104: A sex-linked recessive disorder due to defect in either red or green cone of eye is called
✅ Colour blindness
Q 105: Colour blindness results in failure to discriminate between ..........
✅ Red and green colour
Q 106: Colour blindness results occurs in 8% of males and ………. of females.
✅ 0.4%
Q 107: The son of a woman heterozygous for colour blindness has a ………… chance of being colour blind.
✅ 50%
Q 108: Sickle cell anaemia occurs in both sexes as it is ………… recessive disease.
✅ Autosome-linked
Q 109: Sickle cell anaemia is controlled by a pair of alleles such as .........
✅ HbA & HbS
Q 110: The genotype of sickle cell anaemic person is
✅ HbSHbS
Q 111: Sickle cell anaemia is caused by the substitution of Glutamic acid by ……… at the sixth position of the β-globin chain of the haemoglobin (Hb).
✅ Valine
Q 112: Sickle cell anaemia is due to the single base substitution at the sixth codon of the β-globin gene from GAG to …………
✅ GUG
Q 113: In Sickle cell anaemia, shape of the ……… changes from biconcave disc to elongated sickle like structure under low oxygen tension.
✅ RBC
Q 114: …………… is an autosomal recessive disease resulting from an inborn error of metabolism.
✅ Phenylketonuria
Q 115: Phenylketonuria is due to mutation of a gene that codes for the enzyme ……………… responsible for the conversion of an amino acid phenylalanine into tyrosine.
✅ Phenylalanine hydroxylase
Q 116: In a patient with Phenylketonuria, phenylalanine accumulates and converts into …………… and other derivatives.
✅ Phenyl pyruvic acid
Q 117: An autosome-linked recessive blood disease that results in reduced synthesis of α or β globin chains of haemoglobin is called ………….
✅ Thalassemia
Q 118: In α Thalassemia, production of α globin chain is affected due to the mutation or deletion of two closely linked genes …………. on chromosome 16.
✅ HBA1 & HBA2
Q 119: In β Thalassemia, production of β globin chain is affected due to the mutation of a single gene HBB on ………….
✅ Chromosome 11
Q 120: Thalassemia is a quantitative problem of haemoglobin whereas …………. is a qualitative problem.
✅ Sickle-cell anaemia
Q 121: The gain or loss of chromosomes due to failure of segregation of chromatids during cell division is known as .........
✅ Aneuploidy
Q 122: An increase in a whole set of chromosomes due to failure of cytokinesis after telophase stage of cell division is known as
✅ Polyploidy (Euploidy)
Q 123: Which of the following is not a chromosomal disorder?
Myotonic dystrophy, Down’s syndrome, Turner’s syndrome, Klinefelter’s Syndrome.
✅ Myotonic dystrophy
Q 124: The presence of an additional copy of chromosome number 21 (trisomy of 21) is called
✅ Down’s syndrome
Q 125: Down’s syndrome was first described by ……….
✅ Langdon Down
Q 126: Karyotype of Down’s syndrome is ........
✅ 45 A + XX or 45 A + XY
Q 127: A child with short stature, small round head, broad flat face, furrowed big tongue and partially open mouth may have ..........
✅ Down’s syndrome
Q 128: The presence of an additional copy of X-chromosome in male (trisomy) is called
✅ Klinefelter’s Syndrome
Q 129: Karyotype of Klinefelter’s Syndrome is
✅ 44 A + XXY
Q 130: Feminine development such as Gynaecomastia, tall stature and sterility are the features of
✅ Klinefelter’s Syndrome
Q 131: The absence of one X chromosome in female (monosomy) is known as
✅ Turner’s syndrome
Q 132: Karyotype of Turner’s syndrome is ........
✅ 44 A + XO
Q 133: Sterility, rudiment ovaries, short stature and lack of other secondary sexual characters are the features of .........
✅ Turner’s syndrome