CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 16 - MCQExams.com

Experimental evidences of chromosomal  theory of inheritance was given by
  • HT Morgan
  • TH Morgan
  • H de Vries
  • DH Vries
Chromosomal theory of inheritance was given by
  • Morgan et al
  • Sutton and Boveri
  • Hugo de Vries
  • Gregor J. Mendel
Which one of the Mendel traits of Pea was recessive
  • Tall height
  • Green pod
  • Green seed colour
  • Round seed.
Choose the correct answer from the alternatives given.
Match column I with column II and select the correct option from the given codes.
Column IColumn II
A.Autopotyploidy(i)2n + 1
B.Trisomy(ii)AAAA
C.Allopolyploidy(iii)AABB
D.Nullisomy(iv)2n 2
  • A-(ii), B-(i), C-(iii), D-(iv)
  • A-(iv), B-(i), C-(ii), D-(iii)
  • A-(ii), B-(iv), C-(iii), D-(i)
  • A- (ii), B- (i), C-(iv), D-(iii)

Children have A and B types of blood. What are the blood types of parents not possible?   
  • A and O
  • AB and O
  • AB and A
  • A and B
Sometimes a gene which carries a major disadvantage in homozygous state confers an advantage in the heterozygous condition. Explain by giving a suitable example.
  • Down's syndrome
  • Sickle cell anemia
  • Cystic fibrosis
  • None of the above
Which one of the following symbols and its representation used in human pepigree analysis is correct 
  • $$O $$= unaffected male
  • $$\Box $$ = unaffected female
  • $$\blacklozenge $$ = male affected
  • $$\Box =O$$ = matng between relatives.
In Drosophila, the allele for a normal grey body colour G is dominant to ebony body g. The following table summarises the results of several crosses.


S. No.CrossResult
1.strain 1*ggall wild-type
2.strain 2*gg1 wild type: 1 ebony
3.strain 3*ggall ebony
4.strain 4*Gg3 wild type:1 ebony

Which strain both have the genotype Gg?
  • 1 and 3
  • 1 and 4
  • 2 and 3
  • 2 and 4

Study the above pedigree of an autosomal recessive disorder and identify genotypes of $$IA, IIA $$ & $$IIB$$ from the given options
1069652_e195ade8cea6456d8474ca06537e55b1.png
  • $$Aa, Aa, Aa$$
  • $$AA, Aa, AA$$
  • $$AA, Aa, Aa$$
  • $$AA, AA, Aa$$
How many of the following diseases can be studied with the help of pedigree chart? 
Turner's syndrome, Phenylketonuria, Down's syndrome, Sickle-cell anemia, Klinefelter's syndrome, Haemophilia, Cystic fibrosis, Myotonic dystrophy
  • All
  • Six
  • Five
  • Four
When a homozygous normal vision woman marries a color blind man in the progeny 
  • All the sons are normal
  • All the daughter are normal
  • All the daughter with color blind allele
  • All these are seen
The sex of an infant is not a case of inheritance of characteristics.
  • True
  • False
The symbol $$\blacklozenge $$ in pedigree indicates
  • Male affected
  • Sex unspecified and affected
  • Male unaffected
  • Sex unspecified and unaffected
What is the ploidy level of nucellus, MMC, functional megaspore and female gametophyte?
  • 2n, n, 2n, 2n
  • 2n, n, 2n, n
  • 2n, 2n, n , n
  • n, 2n, n, n
Above pedigree chart show 
1110169_ba9c9d6093c249c9b9756074e140c1f3.PNG
  • Autosomal dominant trait
  • Sex-linked recessive trait
  • Autosomal recessive trait
  • Sex-linked dominant trait
Sex determination in human being is ________
  • XX-XX Type
  • XX-XO type
  • XX-XY types
  • XO-XX
Character traced in this pedigree is 
1083288_d80cb114c34c4983a8cee099056dff35.PNG
  • X linked recessive- color blindness
  • X linked dominant - incontinentia pigment
  • Autosomal dominant - Alzhemer's diseases
  • Autosomal recessive - alkaptonuria
How many types of zygotic combination are possible between a cross Aa BB Cc Dd x AA bb Ca DD
  • 32
  • 128
  • 64
  • 16
The type of inheritance shown in the following pedigree chart is 
1076932_000d1a67c3b44558b77135f1c247f34a.PNG
  • Autosomal dominant trait
  • Autosomal recessive trait
  • Sex-linked dominant triat
  • Sex -linked recessive trait.
Which one of the following mutations is not hereditary?
  • Germ line mutation
  • Somatic mutation
  • Both A and B
  • None of the above
Given are some organisms.
(I) Fowl (II) Humans (III) Grasshopper
Following alphabets related to the given animals.
Male homogametic - A
Female heterogametic -B
Male heterogametic - C
Female homogametic - D
Which of the following options correctly describes the given animals in terms of sex determination?
  • (I) A, B (II) C, D (III) C, D
  • (I) C, D (II) A, B (III) C, D
  • (I) A, D (II) C, D (III) A, D
  • (I) B, C (II) C, D (III) A, B
What proportion of the $$f1$$ generation will be short will wrinkled seeds when pure tall round plant is crossed with pure dwarf wrinkled seeded plant?
  • None
  • $$25\%$$
  • $$50\%$$
  • $$75\%$$
If two genes 'a' and 'b' are linked and show 20% recombination, the proportion of gemetes produced in $$F_1$$ by a dihybrid ++/ab derived from a cross between ++/++ and ab/ab would be 
  • ++ 20% : ab 20% : + a 20% : +b 20%
  • ++ 80% : ab 20%
  • ++ 50% : ab 50%
  • ++ 40% : ab 40% : +a 10% : +b 10%
In what the study of XX-XO type method was done initially?
  • Drosophila
  • Butterfly
  • Grass hopper
  • Squash - bug
Find the incorrect match.
  • Double monosomy - $$2n-1-1$$
  • Compensating nullisomy - $$2n-2+1$$
  • Double tetrasomy - $$2n+2+2$$
  • Amphidiploid - AABB
Genes $$A$$ and $$B$$ are linked $$12 map$$ units apart. A heterozyous individual, whose parents were AAbb and aaBB, would be expected to produce gametes in the following frequencies
  • $$44\%AB$$ $$6\%Ab$$ $$6\%aB$$ $$44\%ab$$
  • $$6\%AB$$ $$44\%Ab$$ $$44\%aB$$ $$6\%ab$$
  • $$12\%AB$$ $$38\%Ab$$ $$38\%aB$$ $$12\%ab$$
  • $$6\%AB$$ $$6\%Ab$$ $$44\%aB$$ $$44\%ab$$
Polyploidy is?
  • Increase in whole set of chromosome
  • Failure of cytokinesis after telophase stage
  • Gain or loss of chromosome
  • Both (a) & (b)
Which of the following pedigree charts does not represent inheritance of disorders like myotonic dystrophy?
Find out the incorrect regarding the mutations.
  • Random, occur in any direction
  • Full-fledged, so there are no intermediate forms
  • Discontinuous, non-cumulated over generations
  • Subjected to natural selection
Study the pedigree chart given below
What does it show:
1475055_18c1ae10294b4e14ab20eadf4ad8d265.PNG
  • Inheritance of phenylketonuria
  • Inheritance of colourblindness
  • Inheritance of myotonic dystrophy
  • Inheritance of hypertrichosis
In a dihybrid cross, when one pair of alleles show incomplete dominance, genotypic ratio comes to?
  • $$3:6:3:1:2:1$$
  • $$1:2:2:4:1:2:1:2:1$$
  • $$9:3:3:1$$
  • $$1:2:1$$
Consider the following four statements (1,2,3 and 4) and select the right option for incorrect statement.
a.Mendelian experiments had large sampling size, which gave greater credibility to the data that he collected.
b.Recessive allele influences the appearance of phenotype even in the presence of an alternative allele.
c.multiple alleles can be found only when population studies are made.
d.In $$F_2$$, generation of Mendelian monohybrid cross, the tall and Dwarf traits were identical to their parental types and showed blending.
  • a and c
  • c and d
  • b and d
  • b and c
In a dihybrid cross, if one character shows co-dominance and the other character shows incomplete dominance. What will be the genotypic ratio in its progenies?
  • $$9:3:3:1$$
  • $$3:1:6:2:3:1$$
  • $$1:1:1:1:4:2:2:2:2$$
  • $$1:1:1:1$$
The karyotype of Klinefelter's and Turner's syndrome are respectively :
  • 44 + XXY ; Trisomy of $$21^{st}$$ chromosome
  • Trisomy of sex chromosome ; Trisomy of $$18^{th}$$ chromosome
  • Monosomy of $$21^{st}$$ and $$18^{th}$$ chromosome
  • $$44 + XXY ; 44 + XO$$
Find the ratio of comb types if a cross is made between poultry of Rrpp and RRPp genotypes
  • $$1:1$$
  • $$1:1:1:1$$
  • $$1:3$$
  • $$3:1$$
Sickle-cell anaemia is due to which of the following mutant gene?
  • CTC - CAC
  • CTC - GAG
  • CAC - GUG
  • GAG - GUG
Which of the following statement for chromosomal theory of inheritance is incorrect?
  • Pairing and separation of a pair of chromosomes would lead to the segregation of a factor they carried
  • Behaviour of chromosomes is parallel to the behaviour of genes
  • The two alleles of a gene pair are located on homologous sites on homologous chromosomes
  • Chromosomes as well as genes occur in pairs
XXX refer to
  • Normal female
  • Super female
  • Meta female
  • Normal (triploid) female
Select the correct match.
  • Phenylketonuria – Autosomal dominant trait
  • Sickel cell anaemia – Autosomal recessive trait, chromosome-11
  • Thalassemia – X linked
  • Haemophilia Y linked
Among the seven pairs of contrasting traits in pea plant as studied by Mendel, the number of traits related to flower, pod and seed respectively were
  • 2, 2, 2
  • 2, 2, 1
  • 1, 2, 2
  • 1, 1, 2
0:0:1


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