CBSE Questions for Class 12 Medical Biology Principles Of Inheritance And Variation Quiz 15 - MCQExams.com

Which among the following cane be considered as a carrier of trait?
480467_f2b5a2719c3a4fa7adeb508a4b36b3ae.png
  • II-2
  • II-4
  • III-2
  • III-3
  • A, B and C are correct
Which of the following condition occurs in the person with genotype XO?
  • Cannot survive.
  • Will have immature, ambiguous (both male and female) reproductive systems.
  • Will be phenotypically female but sterile.
  • Does not produce steroid hormones.
  • None of the above.
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.
Strain 1 cannot grow without arginine due top mutation in: 
  • DNA
  • mRNA
  • Protein
  • The anticodon region of the tRNA
  • rRNA
Huntingtons disease is an inherited autosomal dominant disease characterised by nervous breakdown. What percentage of children will inherit the disease if one of the parents show the presence of one of the allele of a disease?
  • 0%
  • 25%
  • 50%
  • 75%
  • 100%
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.
Which of the following amino acids are not required by strain 3 to grow?
  • Arginine and histidine
  • Threonine and histidine
  • Histidine only
  • Arginine and threonine
  • Threonine only
A tall true breeding  garden pea plant is crossed with a dwarf true breeding garden pea plant. When the $${ F }_{ 1 }$$ plants were selfed the resulting genotypes were in the ratio of
  • 1:2:1 :: Tall homozygous : Tall heterozygous : Dwarf
  • 1:2:1 :: Tall heterozygous : Tall homozygous : Dwarf
  • 3:1 :: Tall : Dwarf
  • 3:1 :: Dwarf : Tall
With reference to the pedigree, the most likely genotype of individual III-5 is
480462.jpg
  • Carrier
  • Unaffected
  • Homozygous recessive
  • Homozygous dominant
  • Heterozygous
Wheat (Triticum turgidum) and rye (Secale cereale) are allowed to bred to produce Triticale which expresses the most desirable characteristics of both species. Which one of the following is correct for the ploidy of the resulting hybrid which possesses four chromosome sets from the maternal wheat plant and two sets from the paternal rye plant?
  • Diploid (2n)
  • Triploid (3n)
  • Tetraploid (4n)
  • Hexaploid (6n)
  • Octoploid (8n)
The given pedigree chart indicate
480364_7678b4b8cab346ee9d86db4fad5bd318.png
  • Autosomal dominant
  • Autosomal recessive
  • X-linked dominant
  • X-linked recessive
  • Insufficient information
The given pedigree depicts a rare disorder through three generations of a family.

The number of females in generation II that passed the disorder to their offspring are?
497051.jpg
  • 0
  • 1
  • 2
  • 3
  • 4
Which of the following statements is correct regarding mutations?
  • Many mutations are recessive, and it is unlikely that both parents will have the same recessive mutation.
  • Mutations are not passed to offspring because they are lethal to the organisms.
  • Mutations only occur in body cells and not in the gametes.
  • Most mutations are fatal and not passed to offspring.
  • Most mutations only occur in body cells and are usually repaired before the cells divide.
Read the passage and answer the following question.

A naturalist studies a species of private that inhabits the rain forest. The females live together in large social groups and compete for position in the social hierarchy, with seniority and food gathering ability as two of the determining factors for the leadership position. Males live within the group until they reach sexual maturity, at which time they leave the group and live on their own, mostly in isolation. Mature males only interact with the females during periods of mating which occur once a year. During mating season males compete for mating opportunities with aggressive displays and battles between males that occasionally lead to significant and even fatal injury. Males are commonly observed during mating season interacting with social groups other than those of their birth. Females give birth an average of five times during their lives, with two children that reach maturity. In addition to studying the behavior of the species, the naturalist identifies the following pedigree:
Black shading indicates that death occurred as a result of aggressive behavior initiated by the individual who died. Gray shading indicates death as a result of disease or as a result of aggressive behavior by another individual.

Which of the following resulting females of this species are often observed feeding and caring for the offspring of other females?
484278.PNG
  • Fear of males
  • The hierarchical structure of the primate social group
  • Kin Selection
  • Instincts triggered by insufficient nutrition
  • Mutualism
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.
Which of the following is true for mutation in strain 4?
  • Renders it dormant
  • Does not affect its ability to synthesize amino acids
  • Causes it to become haploid
  • Is identical to that in strain 1
  • None of the above
Based on the given pedigree, the individual III-5 will have _______ genotype.
497636.jpg
  • Carrier
  • Unaffected
  • Homozygous recessive
  • Homozygous dominant
  • Heterozygous
A child is born with albinism, an inability to produce or deposit the pigment protein, melanin, in skin cells, as well as other pigment-containing cells of the body. His parents do not display the trait of albinism.
How is this possible?
  • The child has only one allele for skin pigmentation, though his parents each have two. Having fewer genes produces his albino characteristics.
  • A spontaneous mutation, not present in either parent, has resulted in the child producing the albino protein. The albino protein displaces the normal melanin.
  • The normal DNA from both parents has combined to produce a new form of DNA in the child. This abnormal DNA codes for the albino protein.
  • The parents each have one normal DNA allele and one that codes for albinism. The parents produce enough normal melanin protein to allow normal skin color, but the child cannot.
The tumor suppressor gene APC, when mutant, causes a precancerous condition called familial adenomatous polyposis (FAP). FAP has autosomal dominant inheritance. 
What is the probability that two individuals who are heterozygous for the APC mutation would have four children, all without the APC mutation? 
  • 1/64
  • 0.25
  • 1/16
  • 0.125
  • 0.5
According to the chromosomal theory of inheritance, which of the following type of cell division contributes maximum for recombination and genetic variation?
  • Meiosis
  • Mitosis
  • Amitosis
  • Both A and B
Scientists collect cell samples from as many species in an ecosystem as possible, and perform chromosome analysis. They record the number of copies for each chromosome and summarize the data for both the plants and animals. 
What conclusion can be drawn from the data?
526630_de03353b7bb843ebbc05a9fdbe589ed9.png
  • Animal cells are more likely to experience nondisjunction than plant cells.
  • As the number of copies of chromosomes in a cell increases, complexity decreases.
  • Natural selection acts more quickly on animals than on plants.
  • Polyploidy is more common in plants than in animals.
Choose the correct statements regarding genetic disorders.
(I)   Turner's female is a result of aneuploidy. 
(II)  Tritanopia is a sex-linked recessive disorder.
(III) Haemophilia C follows criss-cross pattern of inheritance. 
(IV) Sickle cell anaemia is due to mutation of alleles on chromosome 11.
  • I, IV
  • II, III
  • I, III, IV
  • II, IIV
The recessive state for seed coat colour is
  • Green
  • Grey
  • Yellow
  • White
Monohybrid ratio is
  • 3 : 1
  • 9 : 7
  • 1 : 2
  • 9 : 3 : 3 : 1
The gene of haemophilia is present on X chromosome. If a hemophilic male marries a normal female, the probability of their son being hemophilic is
  • Nil
  • 25%
  • 50%
  • 100%
Genotypic ratio of monohybrid cross is
  • 3 : 1
  • 1 : 2 : 1
  • 1 : 1
  • 9 : 3 : 3 : 1
Chromomeres were discovered by
  • Strasburger
  • Van Beneden
  • Pfitzner
  • Winiwater
How many types of gametes are required for $$F_2$$ generation of a monohybrid cross?
  • 2
  • 4
  • 16
  • 8
After a mutation at a genetic locus, the character of an organism changes due to changes in 
  • RNA transcription
  • Protein synthesis
  • DNA replication
  • Protein structure
The chromosomal basis of inheritance was given by
  • Schleiden & Schwann
  • Sutton & Boveri
  • Singer & Nicholson
  • Morgan & Bridges
Chromosomal theory of inheritance was proposed by ______________.
  • Gregor Mendel
  • Hugo de vries
  • Bridges
  • Sutton and Boveri
  • Bateson and Punnett
Total 512 seeds are collected from the cross$$  WwYy \times WwYy$$. Find the number of plants produced with first dominant and second recessive.
  • 288
  • 96
  • 32
  • 320
The graphical representation to calculate the probability of all possible genotypes of offspring in a genetic cross in called
  • Pedigree analysis
  • Punnet square
  • Chromosome map
  • Genotypic ratio
  • Karyotype
In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree.
692591_d1bf369d0dac421bbfa6ee5d712fbc37.png
  • X-linked recessive
  • Autosomal recessive
  • X-linked dominant
  • Autosomal dominant
Polyploidy gives
  • Hybrid vigour
  • Improved varieties
  • Gigas effect
  • All of the above
In Melandrium, sex determination is of
  • XX-XO
  • ZZ-ZW
  • XX-XY
  • XY-XO
Which of the following is true for the given pedigree?
689265_f95b0398f5d444458c00d08f3657cea4.png
  • Parents are homozygous
  • Parents are heterozygous
  • Parents are homozygous recessive
  • Trait is Y-linked
Down's syndrome is an example of _______________.
  • Aneuploidy
  • Polyploidy
  • Monoploidy
  • Monoconry
Which is true for recessive disease in family A and B?
689745_ae5c1efaa22d4f61aa51af350414c06c.png
  • In family A, both parents are homozygous recessive
  • In family B, both the parents are homozygous dominant
  • In family B, both are parents are heterozygous recessive
  • In family A, both the parents are heterozygous recessive
What result Mendel would have got, had he self pollinated a tall $$F_2$$ homozygous plant?
  • TT and Tt
  • All Tt
  • All TT
  • All tt
In a population of families having three children each, the percentage of population of families having both boys and girls is?
  • $$10$$
  • $$25$$
  • $$50$$
  • $$75$$
Choose the correct answer from the alternatives given.
Consider a cross in which a trait is inherited by incomplete dominance. What percentage of the $$F_2$$ from the mating of homozygous dominant and homozygous recessive, What percent of individuals will possess the dominant phenotype ?
  • 100 percent
  • 25 percent
  • 50 percent
  • 75 percent
Find the correct statement:
  • monosomy and nullisomy are types of euploidy
  • 2n-1 is trisomy
  • Polynoidae are common in animals than plants
  • Polynoidae occurs due to failure in separation of complete set of chromosomes
The following two pedigree describe the autosomal genetic disorders P and Q in Family $$1$$ and Family $$2$$, respectively.
Choose the correct statement from the following options.

772152_c9101bf6a453435d9a97132dc88f54f7.png
  • Both P and Q are dominant traits.
  • P is a dominant trait and Q is a recessive trait.
  • Both P and Q are recessive traits.
  • P is a recessive trait and Q is a dominant trait.
Two pedigrees (P and Q) are given, Individual-$$1$$ in $$F_0$$ generation of pedigree Q is not a carrier of the trait. Circles in the pedigree represent females and squares represent males. Filled shapes indicate affected individuals while unfilled shapes indicate unaffected individuals.
Assuming Mendelian inheritance and complete penetrance of the traits, choose the correct statement(s) from the following.

884571_d2166d26ca04418ca7cda822bdfd0d59.jpg
  • Both pedigrees P and Q represent autosomal recessive traits
  • Both pedigrees P and Q represent autosomal dominant traits
  • Pedigree P represents an autosomal recessive trait and Q represents an autosomal dominant trait
  • Pedigree P represents an X-linked recessive trait and Q represents an autosomal recessive trait
Female plant is diploid and male plant is tetraploid. Find out the correct match regarding this. 
  • Embryo - 3n Endosperm -5n Integument - 2n Egg - n Pollen - 2n Aleurone layer - 4n
  • Embryo - 2n Endosperm -6 n Integument - 2n Egg - 4n Pollen - 4n Aleurone layer - 2n
  • Embryo - 2n Endosperm - 3n Integument - 2n Egg - 4n Pollen - n Aleuronr layer - 3n
  • Embryo - 6n Endosperm - 4n Integument - 3n Egg - n Pollen - 2n Aleurone layer - n
The polyploids which have evolved from plants with the lower chromosome number by a direct increase of the number are called allopolyploid.
  • True
  • False
Study the following pedigree. The transmission of the trait indicates
929344_916f10e27a9e42daa01f3775a6e6e325.JPG
  • autosomal dominance
  • maternal imprinting
  • paternal imprinting
  • mitochondria! inheritance.
In cell of superfemale with 47 chromosomes (44+XXX) visible barr bodies are-
  • 1
  • 0
  • 2
  • 3
In Drosophila, the Y-chromosome does not determine maleness but is necessary for fertility.
  • True
  • False
The concept of an inborn error of metabolism was the first recognition of the relationship between gene activity and metabolic disease, made by
  • Beadle and Tatum with parasitic molds
  • Pauling and Itano with sickle-cell anaemia
  • Archibold Garrod from general family inheritance patterns
  • Watson and Crick, as a natural outcome of their model of DNA
A pedigree chart of a family with an autosomal recessive disease Z is given. Assume that inheritance is Mendelian, and that all individuals with homozygous recessive genotype have the disease. Circles in the pedigree represent females and squares represent males. Filled shapes indicate affected individuals, while unfilled shapes indicate unaffected individuals. If J does not have the recessive allele, the probability that I is a 'carrier of disease Z' is?
885451_5e9c824251c94fe19c11470a824c2d2f.png
  • $$0.67$$
  • $$0.5$$
  • $$0.25$$
  • $$0$$
The inheritance pattern of a gene over generations among humans is studied by the pedigree analysis. Character studied in the pedigree analysis is equivalent to 
  • Quantitative trait
  • Mendelian trait
  • Polygenic trait
  • Maternal trait
0:0:1


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