CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 1 - MCQExams.com

Which one of the following conditions though harmful in itself, is also a potential survivor from a mosquito borne infectious disease?
  • Thalaessaemia
  • Sickle cell anaemia
  • Pernicious anaemia
  • Leukemia
Which of the following is the example of pleiotropy?
  • Haemophilia
  • Thalassemia
  • Sickle cell anaemia
  • Colour blindness
A common test to find the genotype of hybrid is by
  • Crossing of one F$$_2$$ progeny with male parent
  • Crossing of one F$$_2$$ progeny with female parent
  • Studying the sexual behaviour of F$$_1$$ progenies
  • Crossing of one F$$_1$$ progeny with male parent
Which of the following pairs is wrongly matched ?
  • XO type sex determination : Grasshopper
  • Starch synthesis in pea : Multiple alleles
  • T.H. Morgan : Linkage
  • ABO blood grouping : Co- dominance
Experimental verification of the chromosomal theory of inheritance was done by
  • Sutton
  • Boveri
  • Morgan
  • Mendel
What is the genetic disorder in which an individual has an overall masculine development gynaecomastia, and is sterile?
  • Turner's syndrome
  • Klinefelter's syndrome
  • Edward syndrome
  • Down's syndrome
Male XX and female XY sometime such conditions occur due to
  • Deletion
  • Transfer of segments in X and Y chromosomes
  • Aneuploidy
  • Hormonal imbalance
In a testcross involving $$F_1$$ dihybrid flies, more parental type offsprings were produced than the recombinant type offsprings. This indicates that
  • The two genes are located on two different chromosomes.
  • Chromosomes failed to separate during meiosis.
  • The two genes are linked and present on the same chromosome.
  • Both of the characters are controlled by more than one gene.
A human female with Turner's syndrome
  • Has 45 chromosomes with XO
  • Has one additional X chromosome
  • Exhibits male characters
  • Is able to produce children with normal husband
Select the correct statements:
  • Spliceosomes take part in the transcription.
  • Franklin Stahl coined the term "linkage".
  • Transduction was discovered by S. Altman.
  • Punnett square was developed by British scientist.
Discontinuous variations are
  • Mutations
  • Acquired characters
  • Essential features
  • Nonessential features
Assertion:  Plasmids are single stranded extra chromosomal DNA.

Reason:  Plasmids are found in Eukaryotic cells.
  • If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  • If the assertion is true but the reason is false
  • If both the assertion and reason are false
  • If the assertion is false but reason is true
The percentage of heterozygous individuals obtained in F$$_{2}$$ generation from selfing the plants with genotype Rr would be
  • 24
  • 50
  • 75
  • 100
Grain colour in wheat is determined by three pairs of polygenes. Following the cross AABBCC (dark colour) x aabbcc (light colour), how many plants will be produced with the genotype AABBCC?
  • None
  • Five
  • One 
  • Ten
Which of the following disease, has a XXY chromosome constitution?
  • Down's syndrome
  • Turner's syndrome
  • Klinefelter's syndrome
  • Patau's syndrome
A pregnant woman who has done amniocentesis test finds an extra Barr body in her embryo. The syndrome which is likely to be associated with the embryo is ________________.
  • Down syndrome
  • Patau syndrome
  • Edward syndrome
  • Klinefelter syndrome
Given above is a pedigree chart of a family with five children. It shows the inheritance of attached earlobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals. Which one of the following conclusions drawn is correct?

67817_1c0a9db81730415094bd6d0d5b404943.png
  • The parents are homozygous recessive.
  • The trait is Y linked.
  • The parents are homozygous dominant.
  • The parents are heterozygous.
In sickle cell anaemia, the death is caused when the lethal genes are present in
  • Heterozygous condition
  • Homozygous dominant condition
  • Homozygous recessive condition
  • Co-dominant condition
Assertion:  Phenylketonuria is a recessive hereditary disease caused by body's failure to oxidise an amino acid phenylalanine to tryrosine, because of a defective enzyme.

Reason:  It results the presence of phenylalanine acid in urine.
  • If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  • If the assertion is true but the reason is false
  • If both the assertion and reason are false
  • If the assertion is false but reason is true
How many different types of gametes can be formed by $$F_1$$ progeny, resulting from the following cross?
AABBCC x aabbcc
  • 8
  • 1
  • 27
  • 64
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
In pedigree analysis, circles represent 
  • Normal males
  • Normal females
  • Affected males
  • Affected females
In a pedigree analysis, the diagram represents 
226102.jpg
  • Unrelated mating
  • Consanguineous mating
  • Affected parents
  • Siblings
  • Non-identical twins

Test cross is used to                             
  • Check heterozygosity in F$$_1$$ generation
  • Check heterozygosity in F$$_2$$ generation
  • Check independent assortment
  • Both A and B
The cross used to ascertain whether the plant is homozygous or heterozygous is
  • Hybrid cross
  • Reciprocal cross
  • Test cross
  • Monohybrid cross
The functional unit of mutation is a
  • Gene
  • Muton
  • Recon
  • Cistron
Chromosome complement with 2n-1  configuration is
  • Monosomy
  • Nullisomy
  • Trisomy
  • Tetrasomy
Euploidy is best explained by
  • One chromosome less than the haploid set of chromosomes
  • Exact multiples of a haploid set of chromosomes
  • One chromosome more than the haploid set of chromosomes
  • One chromosome more than the diploid set of chromosomes
Which of the following plants was selected by Mendel for his experiment?
  • Garden pea
  • Pigeon pea
  • Sweet pea
  • Moong
In male grasshoppers and moths, there are two pairs of autosomes and
  • X only
  • X and Y
  • Y only
  • None of the above

Relative morphologies of chromosomes  an individual indicate

his/her

 
  • Genotype
  • Phenotype
  • Pedigree chart
  • Karyotype
A cell with less number of chromosomes than the normal is known as
  • Aneuploid
  • Gametic
  • Monosomic
  • Polyploid
  • Trisomatic
Choose the correct statement about mutations.
  • Rates tend to be very low in most populations
  • Rates tend to be high in most populations
  • Irreversible
  • Only certain gene locations are affected
  • none of the above
The total number of chromosomes in an organism with haploid number of 18 would be
  • 18
  • 16
  • 26
  • 36
  • 46
Polyploidy is induced through
  • Colchicine
  • Irradiation
  • Mutagenic chemicals
  • Ethylene
Lethal mutations were first detected by
  • Morgan
  • Muller
  • L. Cuenot 
  • Bateson
  • None of the above
As per Lyon's hypothesis, one of the two X chromosomes undergoes heterochromatisation and is called as
  • Barr body
  • Karyotypic body
  • Genotypic body
  • Phenotypic body
Consider the following pedigree over four generations and mark the correct answer below about the inheritance of haemophilia. 
631223_8de97decaea14621aa24a6cf7733799f.png
  • Haemophilia is X-linked dominant
  • Haemophilia is autosomal dominant
  • Haemophilia is X-linked recessive
  • Haemophilia is Y-linked dominant
Transposon was discovered by
  • Sutton
  • Strassburger
  • Fischer
  • McClintock
According to the chromosomal theory of inheritance, the hereditary unit which occurs in pair is known as 
  • DNA
  • RNA
  • Proteins
  • Genes
Which is not a genetic disorder?
  • Sickle cell anaemia
  • Down syndrome
  • Type 2 diabetes
  • ADHD
Mutation is
  • Change in gene frequency
  • Genetic drift
  • Change in base pairs in DNA molecule
  • Environmental mechanism of evolution
Mutation refers to sudden change in
  • Phenotype
  • Maturation time
  • Metabolic rate
  • Genetic make up
Excessive growth of hair on the pinna is a feature found only in males because
  • The gene responsible for the character is recessive in females and dominant only in males
  • The character is induced in males as males produce testosterone
  • The female sex hormone estrogen suppresses the character in females
  • The gene responsible for the character is present on the Y chromosome only
Mutation is a change that is
  • Never inherited
  • Inherited only in $$F_2$$ generation
  • Inherited
  • Responsible for plant growth
Which is the main category of mutation?
  • Genetic mutation
  • Zygotic mutation
  • Somatic mutation
  • All the above
Which of the following is not an aneuploidy?
  • Monoploid
  • $$2n-1$$
  • Trisomic
  • $$2n+2$$
Triticale is an example of.
  • Autopolyploidy
  • Allopolyploidy
  • Aneuploidy
  • None of the above
Sudden and a heritable change in a character/gene of an organism is 
  • Selection
  • Heterosis
  • Inbreeding
  • Mutation
In diploid set of chromosomes, deletion and addition of a member leads to.
  • Aneuploidy
  • Euploidy
  • Polyploidy
  • Triploidy
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