CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 7 - MCQExams.com

Which has an additional X-chromosome?
  • Turner's syndrome
  • Klinefelter's syndrome
  • Super female
  • Down's syndrome
The visual representation of Mendelian inheritance is given by 
  • Punnett square
  • Labelled diagram
  • Heterozygote table
  • Homozygote table
Mendel carried out his experiment on pea plant. He focused on which of the following traits?
  • Shape of seed
  • Colour of seed
  • Both A and B
  • Size of seed
A normal sperm in humans possess
I. an X chromosome
II. 23 chromosomes
III. a Y chromosome
  • I only
  • II only
  • III only
  • I or III only
  • Both B and D
Which of the following explains about breeding animals closely related in a pedigree?
  • Inbreeding
  • Codominance
  • Linkage analysis
  • Selective breeding
  • Test crossing
Most mutations are the result of
  • Certain chemicals
  • Random events
  • X-rays
  • Ultraviolet radiation
  • All of the above
All of the following cause extinction except
  • Introduction of a new predator
  • Introduction of a new parasite
  • Introduction of a new mutation
  • Interspecific competition for limited resources
  • Habitat destruction
Which of the following generations of a monohybrid cross shows that all the individuals are same?
  • Parental
  • F$$_1$$
  • F$$_2$$
  • F$$_3$$
  • F$$_4$$
Male heterogametic sex, XX, XO type of sex determination is found in
  • Butterflies
  • Moths
  • Grasshoppers
  • Drosophila
Assume that blue flowered plant is dominant character over the white. When a blue flowered plant is crossed with its white flowered plant, the progeny showed 50% of plants with blue flowers is with white flowers. The genotypes of blue and white parents respectively are
  • bb, bb
  • BB, Bb
  • BB, bb
  • Bb, bb
The inheritance of sex chromosomes in human can be described by the fact that:
  • The gametes from each parent have either an X or a Y chromosome.
  • The gamete from the mother has either an X or Y chromosomes.
  • The gamete from the father has either an X or a Y chromosome.
  • The gamete from the father only has an X chromosome.
  • The gamete from the mother has only a Y chromosome
An experiment was performed to test the ability of one wild type and four mutant strains of E.coli  bacteria to grow in either minimal media or media that was supplemented with various amino acids.

Supplement                None              Arginine
Wild-type                    $$+$$             $$+$$
Strain 1                      $$-$$              $$+$$
Strain 2                      $$-$$              $$-$$
Strain 3                      $$-$$              $$-$$
Strain 4                      $$+$$             $$+$$

Supplement                Threonine              Histidine
Wild-type                    $$+$$             $$+$$
Strain 1                      $$-$$              $$-$$
Strain 2                      $$+$$              $$-$$
Strain 3                      $$-$$              $$+$$
Strain 4                      $$+$$             $$+$$
A $$\left(+\right)$$ sign indicates growth and a $$\left(-\right)$$ sign indicates no growth.
One of the following is true for strain 2:
  • Cannot produce arginine
  • Cannot produce threonine
  • Cannot produce histidine
  • Cannot produce glycine
  • Can produce all amino acids
Which of the following does not explains that cell receives more than the normal number of chromosomes?
  • Tetraploid
  • Diploid
  • Monosomic
  • Polyploid
  • Trisomatic
Which of the following true for an offspring formed as a result of sexual reproduction? 
  • The offspring gets a full set of genes from the mother and from the father.
  • The offspring gets half the genes from the mother and half the genes from the father.
  • The offspring gets all of its genes from the father.
  • The offspring gets a random mixture of genes from the mother and father.
  • The offspring gets all of its genes from the mother.
Which of the following is true for the inheritance of sex chromosomes in humans?
  • The gametes from each parent have either an X or a Y chromosome.
  • The gamete from the mother has either an X or a Y chromosome.
  • The gamete from the father has either an X or a Y chromosome.
  • The gamete from the father only has an X chromosome.
  • The gamete from the mother only has a Y chromosome.
The position of an altered amino acid sequence in a protein and position of a mutation in a gene are
  • Not related
  • Inversely related
  • Related in bacteria but not in mammals
  • Species-dependent
  • In the same relative position
Genetic variations leading to evolution takes place due to the mutations in 
  • Skin cells
  • Body cells
  • Brain cells
  • Sex cells
  • Embryo cells
Choose the correct statement about tetraploid individual.
  • One copy of each chromosome
  • Two copies of each chromosome
  • Four copies of each chromosome
  • Two copies of a single chromosome
  • Four copies of a single chromosome
A phenotypic ratio of $$3 : 1$$ takes place when
  • The alleles are incompletely dominant.
  • Only recessive traits are involved.
  • Only dominant traits are involved.
  • Alleles segregate during meiosis.
  • Crossing over has occurred in anaphase II.
Which of the following is responsible for 21 trisomy in humans?
  • Pleiotropy
  • Polygenic inheritance
  • Epistasis
  • X- inactivation
  • Nondisjunction
If a couple has two boys and one girl, the probability of the next girl child to be born is
  • $$\displaystyle\frac{1}{4}$$
  • $$\displaystyle\frac{1}{3}$$
  • $$\displaystyle\frac{1}{2}$$
  • $$\displaystyle\frac{2}{3}$$
  • $$\displaystyle\frac{3}{4}$$
Most of the mutations occur due to
  • Certain chemicals
  • Ionizing radiation
  • Infrared radiation
  • Ultraviolet radiation
  • Random events
Which of the following is not caused by a mutation in DNA?
  • Sickle cells anemia
  • Phenylketonuria
  • Cystic fibrosis
  • AIDS
  • Haemophilia
How is the sex of the baby determined?
  • Sex chromosomes of mother
  • Sex chromosomes of father
  • 'X' chromosome of unfertilised egg
  • All 23 pairs of chromosomes
Using the pedigree shown, how many individuals can definitely be identified as heterozygous? 
529868.PNG
  • 10
  • 11
  • 8
  • 9
Which of the following genetic disorders is caused by a nondisjunction of chromosomes during meiosis?
  • Huntington Disease
  • Klinefelter Syndrome
  • Hemophilia
  • Colorblindness
  • Tay-Sachs Disease
Which of the following represents the genotype for an organism in which nondisjunction has occurred?
 I. 46, XX
 II. 47, XY
 IlI. 45, XO 
  • I only
  • II only
  • III only
  • I and II only
  • II and III only
Nondisjunction is the failure of homologous chromosomes to separate properly during meiosis. Below is a karyotype of a person that is the product of a nondisjunction event.

Which of the following statements below could predict the events that occurred to produce the individual shown in the karyotype above?
529346_811d6b5f5e0c469da8efeebf5e6d5d26.png
  • Because this individual was female, one X chromosome was inactivated. This inactivation prevents the appearance of two X chromosomes on the karyotype.
  • While the cells that gave rise to this individual were forming, one of the gametes became cancerous. Errors in cell division caused by cancer produced the karyotyped individual with an abnormal chromosome number.
  • During meiosis, two X chromosomes combined to make one larger-than-average X chromosome. Because the amount of DNA in the cell is unchanged, this had no effect on the development of the karyotyped individual.
  • A mistake was made during meiosis, resulting in either the sperm or the egg missing its sex chromosome. Fertilization of this unusual gamete produced an individual with only 45 chromosomes.
Using the pedigree in the image, what is the likely genotype of individual number $$3$$ in the image?
529270.pngixj
  • Homozygous dominant
  • Heterozygous
  • Homozygous recessive
  • It is not possible to determine from the data given
Using the pedigree in the image, what type of inheritance pattern is most likely?
529286.pngixjsv%3D
  • Autosomal dominant
  • Autosomal recessive
  • Sex-linked recessive
  • Holandric
The pedigree below shows tracks the inheritance of colorblindness, a sex-linked recessive condition.

If male number two has a child with a woman who is not colorblind, but whose father was, what is the chance that they will have a daughter who will be a carrier for the trait out of all the children born?
529291.pngixjsv%3D
  • $$0$$
  • $$0.25$$
  • $$0.5$$
  • $$1$$
Using the pedigree in the image, what is the likely genotype of individual number 1?
529299.pngixjsv%3D
  • $$X^NY$$
  • $$X^NX^n$$
  • $$X^nX^n$$
  • $$X^NX^N$$
The image shows the chromosomes of a person.
Which terms best describe this person?
529295_a77a816cf1264859bc0f22cfa01aaea7.png
  • Female with no immediately identifiable disorders
  • Male with no immediately identifiable disorders
  • Female with a disorder
  • Male with a disorder
From the following pedigree chart of a family, one can make an analysis that,

570879_0d6a3d57f0eb48569164efe4842e07ad.png
  • It is an autosomal dominant trait
  • It is an autosomal recessive trait
  • It is an allosomal dominant trait
  • It is an allosomal recessive trait
Which of the following theory was supported by linkage?
  • Law of independent assortment
  • Theory of linkage
  • Theories for origin of life
  • Both A and B
According to the chromosomal theory of inheritance, the genes are located on the chromosomes ............. manner.
  • Linear
  • Eccentrically
  • Circular
  • None of the above
Double lines in pedigree analysis show
  • Sex unspecified
  • Consanguineous marriage
  • Unaffected offspring
  • Normal mating
The genotype of the individual marked #2 on the pedigree shown could father children with all of the following genotypes except 
534376.jpg
  • X$$^A$$X$$^a$$
  • X$$^a$$X$$^a$$
  • X$$^A$$X$$^A$$
  • X$$^a$$Y
  • X$$^A$$Y
The pedigree above represents four generations of a family affected by albinism, an autosomal recessive trait. 
What are the genotypes of the parents of individual 2 in generation 2?

534323.jpg
  • AA and aa
  • aa and aa
  • Aa and Aa
  • Aa and aa
  • None of the above
Boveri conducted studies related to chromosomal theory of inheritance on
  • Drosophila
  • Sea urchin
  • Grasshoppers
  • All of the above
According to the chromosomal theory of inheritance, chromosomal genes exist in pairs in .............. type of cell.
  • Monoploid
  • Diploid
  • Polyploid
  • Both A and B
Which of the following theory is dependent on the chromosomal theory of inheritance?
  • Recombination
  • Mendelian inheritance
  • Incomplete dominance
  • Both A and B
The ............ genes are inherited together in all the generations.
  • Linked
  • Dominant
  • Recessive
  • All of the above
Mendelian factors and chromosomes maintain their ............. from generation to generation.
  • Segregation
  • Individuality
  • Dominance
  • None of the above
According to the chromosomal theory of inheritance, the contrasting pair of genes are known as 
  • DNA
  • RNA
  • Proteins
  • Allele
The given diagram supports which of the following theory?
577713_a76e2b0172154efdb6c1acbc0f5b183d.png
  • Chromosomal theory of inheritance
  • Theory of linkage
  • Law of independent assortment
  • Both A and C
The two genes located on separate chromosome produce .............. recombinants.
  • 50%
  • 25%
  • 75%
  • All of the above
Choose the correct statement.
A) Chromosomal theory of inheritance supports dominance.
B) Chromosomes are the hereditary unit which exists with multiple characters known as an allele.
C) The Mendelian factor is located on the chromosomes.
  • Only A
  • Only B
  • Only C
  • All of the above
Mendelian inheritance was supported by the 
  • Artificial selection
  • Chromosomal theory of inheritance
  • Theory of linkage
  • Both B and C
According to chromosomal theory of inheritance, the inheritance of genes depends upon
  • Distance between two genes located on the same chromosome
  • Location of genes on a same or different chromosomes
  • Characters carried by the chromosomes.
  • Both A and B
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