CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 9 - MCQExams.com

Numerical change in chromosome number which is not the exact multiple of haploid genome is?
  • Triploid
  • Allopolyploid
  • Autopolyploid
  • Aneuploid
One of the following is a random process
  • Variations
  • Adaptations
  • Evolution
  • Mutations
A change in chromosomal number is called _______________.
  • Polyploidy
  • Aneuploidy
  • Chromosomal mutation
  • Somatic mutation
Euploidy is
  • One chromosome more than haploid set
  • One chromosome more than diploid set
  • One chromosome less than haploid set
  • Exact multiple of haploid set of chromosomes
Which one is found in males only?
  • X-chromosome
  • Y-chromosome
  • $$2$$X-chromosomes
  • X$$+$$X-chromosomes
In human sperm, besides autosomes the chromosome complement contains
  • X and Y
  • Either X or Y
  • Y only
  • X only
The symbol of empty circles used in pedigree analysis represents
  • Normal females
  • Normal males
  • Affected females
  • Affected males
The term mutation was given by
  • De Vries
  • Mendel
  • Darwin
  • Lamarck
Chromosome complement of human male is
  • $$44+AO$$
  • $$44A+XX$$
  • $$44A+XY$$
  • $$44A+XXY$$
A disease found only in males is?
  • Gaucher's disease
  • Lesch-Nyhan disease
  • Hunter's disease
  • Fabry's disease
Turner's syndrome is represented by
  • XYY
  • XO
  • XXY
  • XXX
Addition of individual chromosomes is mutation called
  • Polyploidy
  • Structural mutation
  • Polysomy
  • Point mutation
$$F_2$$ generation is produced by
  • Crossing $$F_1$$ progeny with one of the parents
  • Selfing the progeny of two individual parents
  • Selfing the parents
  • Recessive cross between individual parents
Scientist who was awarded Nobel prize for finding genes to be linearly arranged on chromosomes was
  • Wolf
  • Punnet
  • Morgan
  • Swammerdan
  • Knight
Male XX and female XY develop sometimes due to _______________.
  • Hormonal imbalance
  • Aneuploidy
  • Deletion
  • Transfer of segments between X and Y
Seedless watermelons have been obtained through.
  • Vegetative propagation
  • Haploidy
  • Triploidy
  • Gibberellin application
Identify the wrong statement :-
  • Probability of homozygous dwarf progeny in a cross TT $$\times$$ Tt is zero
  • Probability of homozygous tall progeny in a cross TT $$\times$$ TT is one
  • Probability of heterozygous tall progeny in a cross TT $$\times$$ tt is 0.5
  • Probability of homozygous dwarf progeny in a cross TT $$\times$$ TT is zero.
A condition of not having exact multiple of haploid set is?
  • Aneuploidy
  • Synploidy
  • Polyploidy
  • All the above
In Drosophila sex is determined by
  • X and Y chromosomes
  • Ratio of pairs of X-chromosomes to the pairs of autosomes
  • Ratio of number of X-chromosomes to the sets of autosomes
  • Whether the egg is fertilized or develops parthengenetically
Ultraviolet radiations cause mutations due to
  • Formation of thymine dimers/ thymidine
  • Deletion of base pairs
  • Addition of base pairs
  • Methylation of base pairs
In Garden Pea, round shape is dominant over wrinkled shape. A pea plant heterozygous for round shape of seed is selfed and 1600 seeds produced during the cross are subsequently germinated. How many offspring will have parental phenotype
  • 1600
  • 800
  • 400
  • 1200.
A recessive trait in garden pea is:
  • Wrinkled seeds
  • Tall stem
  • Round seeds
  • Coloured seed coat
Chromosomal doubling for producing polyploid plants is carried out by.
  • PEG
  • NAA
  • EMS
  • Colchicine
With respect to phenyl ketonuria identify which statement is not correct :-
  • It is an error in metabolism
  • Caused due to autosomal recessive trait
  • It is an example of pleiotropy
  • It is a case of aneuploidy.
A cross between two tall Garden Pea plants produced all tall plants. The possible genotypes of the parents are
(I) TT, TT (II) TT, Tt (III) Tt, tt (IV) Tt, Tt
Correct answer is ____________.
  • III, IV
  • I, IV
  • I, II
  • II, III.
Find the correct statements
(i) $$F_1$$ progeny is the first hybrid generation and progeny resembles either of a parent.
(ii) $$F_2$$ progeny is a resultant hybrid generation of cross-pollination among $$F_1$$ progeny and the progeny shows both dwarf and tall plants.
(iii) $$F_2$$ progeny is the second hybrid generation produced by selfing $$F_1$$ hybrids and progeny contains both dwarf and tall plants.
(iv) Proportion of probability of plants that are dwarf is 1/4 of $$F_2$$ plants while 3/4 of $$F_2$$ plants are tall.
  • i, ii, iii, iv
  • i, iii, iv
  • i, ii, iv
  • iii, iv.
A sudden spontaneous change in structure and action of a gene is called
  • Variation
  • Allelomorph
  • Linkage
  • Mutation
Given below is a pedigree chart with symbols for sex-linked trait in humans. The trait of the pedigree chart is?
689303_f99a809081884036a2274839dd0f43b3.jpg
  • Recessive Y-linked
  • Recessive X-linked
  • Dominant Y-linked
  • Dominant X-linked
Blackening of exposed urine is a metabolic disorder due to
  • Phenylalanine
  • Tyrosine
  • Homogentisic acid
  • Valine replacing glutamic acid
  • Glutamic acid replacing valine
Number of genetic disorders in human beings is
  • 300
  • 3000
  • 100
  • 150
Which represents correct hexaploid nature of Wheat?
MonosomicHaploidNullisomicTrisomic
(A)$$21$$$$28$$$$42$$$$43$$
(B)$$7$$$$28$$$$40$$$$42$$
(C)$$21$$$$7$$$$42$$$$43$$
(D)$$41$$$$21$$$$40$$$$43$$
  • A
  • B
  • C
  • D
Which genotype and phenotype is a result of aneuploidy in sex chromosomes?
  • $$22$$ pairs $$+$$ XXY male
  • $$22$$ $$+$$ XX female
  • $$22$$ pairs $$+$$ XXXY female
  • $$22$$ pairs $$+$$ Y female
The technique employed in human genetic counselling is?
  • Serological technique
  • Polyploidy
  • Pedigree analysis
  • Amniocentesis
  • Genetic engineering
Turner's syndrome is due to
  • Monosomy
  • Bisomy
  • Trisomy
  • Polyploidy
The condition of an extra chromosome in addition to its homologous pair is
  • Trisomy
  • Monosomy
  • Polyploidy
  • Nullisomy
Study the pedigree chart of certain family given here and select the correct conclusion.
689646_22e3ddf4638c457e91dff0c25caaca4d.jpg
  • The female parent is heterozygous
  • The parents could not have had a normal daughter for this character
  • The trait under study could not be colour blindness
  • The male parent is homozygous dominant
Which one is correctly matched?
  • Erythroblastosis syndrome- X-linked
  • Down's syndrome - $$44A+XO$$
  • Klinefelter's syndrome- $$44+XXY$$
  • Colour blindness- Y-linked
Moody describes mutation as
  • Factor
  • Saltation
  • Sport
  • Shotgun
Select the correct statement :
  • Darwinian variations are small and directionless.
  • Mutations are random and directionless.
  • Fittness is the end result of the ability to adapt and get selected by nature.
  • All mammals expect whales and camels have seen servical vertebrae.
Study the pedigree chart. What does it show?
689604_792ad101215f45acbf7f574b47b79842.jpg
  • Inheritance of a condition like phenylketonuria as an autosomal recessive trait
  • Inheritance of a recessive sex-linked disease like haemophilia
  • Inheritance of sex-linked inborn error of metabolism like phenylketonuria
  • Pedigree chart is wrong as this is not possible
What type of sex determination is found in Grasshopper?
  • XX-XY
  • ZW-ZZ
  • ZZ-ZY
  • XX-XO
Match the columns.
aMonoploidy$$1$$$$2n-1$$
bMonosomy$$2$$$$2n+1$$
cNullisomy$$3$$$$2n+2$$
dTrisomy$$4$$$$2n-2$$
eTetrasomy$$5$$n

$$6$$$$3n$$
  • a-$$6$$, b-$$5$$, c-$$3$$, d-$$4$$, e-$$2$$
  • a-$$5$$, b-$$2$$, c-$$4$$, d-$$1$$, e-$$3$$
  • a-$$5$$, b-$$1$$, c-$$4$$, d-$$2$$, e-$$3$$
  • a-$$1$$, b-$$5$$, c-$$3$$, d-$$2$$, e-$$4$$
  • a-$$2$$, b-$$1$$, c-$$3$$, d-$$6$$, e-$$5$$
In a pedigree analysis $$\square = O$$ represents.
  • Consanguineous mating
  • Affected parents
  • Siblings
  • Unrelated mating
What is correct?
  • Monosomy and nullisomy are two types of euploidy
  • Polyploidy is more common in animals than in plants
  • Polyploids occur due to failure in separation of complete sets of chromosomes
  • $$2n-1$$ is trisomy
  • Nonhomologous chromosomal duplication produces autopolyploidy
Which one of the following symbols and is representation, used in human pedigree analysis is correct?
A man with extra X-chromosome suffers from
  • Down's syndrome
  • Klinefelter's syndrome
  • Bleeder's syndrome
  • Turner's syndrome
Heterogamety or formation of two types of gametes is found in.
  • Male Drosophila
  • Female bird
  • Female Drosophila
  • Both A and B
In Drosophila female has a pair of chromosomes
  • ZZ
  • XX
  • YY
  • ZW
Which chromosome condition is Jacob syndrome?
  • $$44+XO$$
  • $$44+XXY$$
  • $$44+XYY$$
  • $$45+XYY4
Which condition zygotic cell will form normal human female child?
  • XX chromosomes
  • Y-chromosome
  • X-chromosome
  • XY chromosomes
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