CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 13 - MCQExams.com

The coupling and repulsion theory of Bateson and Punnett later on modified in linkage and crossing over by Morgan. Two completely linked genes show a dihybrid.
  • $$3:1$$
  • $$1:1$$
  • $$1:1:1:1$$
  • $$9:3:3:1$$
Which of the following statement is not true?
  • Mutation is change in genetic material
  • Total number of chromosome is $$46$$ is Down's syndrome
  • Chromosomal mutation can be easily studied by analysis of Karyotypes
  • Both $$(2)$$ and $$(3)$$
Mendelian dihybrid and dihybrid with linkage are respectively related with how many chromosomes.
  • $$1$$ pair & $$2$$ pair
  • $$2$$ pair & $$1$$ pair
  • $$2$$ pair & $$2$$ pair
  • $$1$$ pair & $$1$$ pair
Which of the disorder is related with the karyotype given?
1502501_bc9b429217274edb8e6e9dc0a69f08ec.png
  • Turner's syndrome
  • Down's syndrome
  • Myotonic dystrophy
  • Cystic fibrosis
A cross between AaBB$$\times$$aaBB yields a genotypic ratio of?
  • $$1$$ AaBB $$: 1$$ aaBB
  • $$1$$ AaBB $$: 3$$ aaBB
  • $$3$$ AaBB $$: 1$$ aaBB
  • All AaBb
Which of the following pedigree charts does not represent inheritance of disorders like myotonic distrophy?
Total number of genotypes and phenotypes in a dihybrid test cross is?
  • $$9$$
  • $$8$$
  • $$16$$
  • $$13$$
Which of the following disease is an autosomal recessive?
  • Phenylketonuria
  • Haemophilia
  • Sickle cell anaemia
  • Both (a) & (b)
Barr body is absent in?
  • Turners syndrome
  • Klinefelter's
  • Huntington's
  • Cystic fibrosis
In Mendel's monohybrid cross for the shapes of pee seeds, 1600 seeds were obtained in F2 generation. What will be the number of round seeds and hybrid round seeds, respectively?
  • 1200 and 800
  • 800 and 1200
  • 400 and 1200
  • 1200 and 400
 
In the given pedigree shaded box represents black guinea pig while non shaded box represent white guinea pig. Black skin is dominant over white skin in guinea pig. What is the possible genotype of III-1 and III-2 respectively?

1556978_84b3eeb7d52c4ce48ae4ca6fb5cfb979.png
  • Bb and bb
  • BB and bb
  • BB and Bb
  • Bb and Bb
Variations caused by mutation, as proposed by Hugo de Vries are:
  • Random and directional
  • Random and directionless
  • Small and directional
  • Small and directionless
Reason of fast speciation in present day crop plants is?
  • Mutation
  • Isolation
  • Recombination
  • Sexual Reproduction
In a dihybrid cross,the $$F_2$$ ratio of $$15:1$$ is due to 
  • Supplementary genes
  • Duplicate genes
  • Recessive epistasis
  • Dominant epistasis
Genotype of blood group 'AB' in human is ______.
  • $$I^A I^B$$
  • $$I^B i$$
  • $$I^A I^A$$
  • $$ii$$
Ploidy level of Nucellus, Endosperm, Polar nuclei, Megaspore mother cell, female gametophyte respectively are
  • $$2n,3n,n,2n,n$$
  • $$2n,3n,2n,n,n$$
  • $$n,2n,n,2n,n$$
  • $$2n,3n,2n,2n,n$$
In living organisms sometimes any nucleotide of the gene changes its position that causes a minor change which is nothing but the _________
  • Transcription
  • Mutation
  • Evolution
  • Translocation
Write true or false for the following statement:
A child who inherits a Y-chromosome from father will be a girl
  • True
  • False
Write true or false for the following statement:
A child who inherits an X-chromosome from father will be a boy
  • True
  • False
The sex of a newborn baby is determined by the chromosome inherited from?
  • The mother
  • The father
  • Mother's father
  • Father' father
Gene library or DNA library has collection of
  • DNA and RNA
  • Any one type of gene of Organism
  • c DNA only
  • All possible genes of all organisms
What is a Mutation?
  • Change in the genetic material of DNA.
  • Permanent and Hereditary change in the DNA.
  • Change in the cytoplasm of the cell.
  • Any kind of variations.
In a human male, a sperm will contain :
  • Both X and Y chromosomes
  • Only Y Chromosomes
  • Only X chromosome
  • Either X or Y Chromosomes
The genome of Caenorhabditis elgans consists of how many base pairs and genes?
  • 3 billion base pairs and 30,000 genes
  • 180 million base pairs and 13,000 genes
  • 4.7 million base pairs and 4,000 genes
  • 97 million base pairs and 18,000 genes
  • 12 million base pairs and 6,000 genes
Crossing over takes place at a stage between 
  • Leptotene and diplotene
  • Pachytene and diplotene
  • Zygotene and pachytene
  • Zygotene and diplotene
In polytene chromosomes dark bands are visible.

These bands are formed by the apposition of
  • Protein particles
  • Chromorneres on chromonemata
  • Nucleosomes
  • None
A husband and wife have normal vision but fathers of both of them were colour blind. Probability of their first daughter to be colour blind is
  • 25%
  • 50%
  • 75%
  • 0%
Chromosomal theory of inheritance was based on
  • Segregation of genes
  • Diploidy and haploidy
  • Sex linkage
  • Presence of sex chromosomes
When a dihybrid cross is fit into a punnett square with 16 boxes, the maximum possible number of different phenotypes available are
  • 8
  • 4
  • 2
  • 16
  • 12
Tizo and Levan's contribution is very significant because they
  • Gave the number of human chromosomes
  • Pointed out mutational changes
  • Identified Barr bodies
  • Detected sex linkage
Match the items in Column - I with Column - II and choose the correct alternative - 

 Column - I Column - II
 A. Sickle-cell anaemia $$7^{th}$$ chromosome
 B. Phenylketonuria $$4^{th}$$ chromosome
 C. Cystic fibrosis $$11^{th}$$ chromosome
 D. Huntington's disease $$10^{th}$$ chromosome
 E. Colour blindness $$12^{th}$$ chromosome
  • A-1, B-3, C-4, D-2, E-5
  • A-2, B-3, C-4, D-5, E-1
  • A-2,,B-1, C-3, D-5, E-4
  • A-4, B-5, C-3, D-2, E-1
  • A-3, B-5, C-1, D-2, E-4
In plant A, 2n = 12 and in plant B, 2n = 16, then what will be the ploidy number of cross breeding plant?
  • 14
  • 28
  • 12
  • 16
Who discovered 'Y' chromosomes?
  • McCarthy
  • McClung
  • Gregor Mendel
  • Nettie Stevens
What would be the number of chromosomes in the ovum (fertilized by a normal sperm) that resulted in the appearance of Klinefelter's syndrome in the offspring?
  • 23
  • 22
  • 21
  • 24
Study the pedigree chart of a certain family given above and select the correct conclusion which can be drawn for the character.
67829_1ee2f54e171b4eba953d0822ae02528e.png
  • The female parent is heterozygous.
  • The parents could not have a normal daughter for this character.
  • The trait under study could not be colour-blindness.
  • The male parent is homozygous dominant.
Experimental verification of the chromosomal theory of inheritance was given by which of the following scientists?
  • Gregor Johann Mendel
  • Hugo de Vries
  • Langdon Down
  • Henking
  • Thomas Hunt Morgan
Due to non-disjunction of chromosomes during spermatogenesis, sperms carry both sex chromosomes (22A+XY) and some sperms do not carry any sex chromosome (22A+0). If these sperms fertilize normal eggs (22A+X), what types of genetic disorders appear among the offsprings?
  • Turner's syndrome and Klinefelter's syndrome
  • Down's syndrome and Klinefelter's syndrome
  • Down's syndrome and Turner's syndrome
  • Down's syndrome and cri-du-chat syndrome
Autosomal mutant allele Hbs causes 
  • Thalassemia
  • Albinism
  • Sickle cell anaemia
  • Agammaglobulinemia
The concept that chromosomes contained genes was proposed by
  • Mendel
  • Watson
  • Crick
  • Bridges
Which of the following discoveries resulted in a Nobel Prize?
  • Genetic engineering
  • X-rays induce sex-linked recessive lethal mutations
  • Cytoplasmic inheritance
  • Recombination of linked genes
Moody describes the mutation as
  • Sports
  • Saltation
  • Factors
  • Shotgun
Pleiotropy is the term that refers to the situation in which a gene influences more than one trait. Its example is given by
  • Sickle cell anaemia
  • Hemophilia
  • Colour blindness
  • Only (a) and (b)
'XY' male type can be noticed in the following organisms.
  • Rumex, Coccinia and Melandrium
  • Melandrium, Drosophila and Man
  • Rumex, Drosophila and Sphaerocarpos
  • None of the above
Phenotypic and genotypic ratios according to Mendel's pattern of inheritance is 
  • Different
  • Same
  • Average
  • None of the above
Mrs. Verma has an autosomal gene pair 'Bb' and she contain x-linked gene 'd'. What is the percentage of gamete, which contain 'bd' genes?
  • 1/2 or 50%
  • 1/4 or 25%
  • 3/4 or 75%
  • 1 or 100%
Occurrence of cells in diploid organisms containing multiples of the 2n genomes is known as
  • Aneuploidy
  • Polytene
  • Polyploidy
  • Monoploidy
Heterozygosity can be ascertained by
  • Test cross
  • Reciprocal cross
  • Blending inheritance
  • Multiple crossing
Mutations are caused by ______.
  • Polyploidy
  • Hybridization
  • Aneuploidy
  • All of the above
If mutation occurs in sex chromosomes, it is called as
  • Autosomal mutation
  • Germinal mutation
  • Lethal mutation
  • Interference
The condition in which there are too many or few copies of one of the chromosomes is termed as 
  • Aneuploidy
  • Polytene
  • Polyploidy
  • Monoploidy
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