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Saturday, October 23, 2021

MCQS BASED ON CROSSES AND RATIO ( INHERITANCE AND VARIATION)

 

CHAPTER:- INHERITANCE AND VARIATION 

MCQS FOR PRACTICE

1.  Genes located at the identical loci of homologous chromosomes are called:

     a) Polygenes         b) Homozygous 

     c) Alleles                              d) Oncogenes

2.     The process involving mating of individuals, more closely related than average of the population to which they belong is called.

     a) Inbreeding                       b) Interbreeding 

     c) Hybridization                           d) Selfing 

3.     When the identical gene loci on homologous chromosomes produce different phenotypes, these gene loci bear:

     a) Heterozygous alleles   b) Different genes 

     c) Dominant genes d) homozygous alleles

4.  The external appearance of an individual for any trait or traits is called:

     a) Phenocopy                   b) Homozygous 

     c) Phenotype                    d) Genotype 

5.  Mendel was lucky because the genes for    seven characters selected by him in pea were distributed on seven different chromosomes. This was also one of the reasons for his success.  Now, if two or more of these characters (i.e.  Their genes) were located on the same chromosome, which of the Mendel's Laws would be affected?

     a) Law of dominance       

     b) Law of independent assortment

     c) Law of segregation      d) All the three

6.  An offspring with Tt genotype is crossed with an individual with tt genotype. This is an example of -

     a) Test cross        b) Monohybrid cross 

     c) Inbreeding       d) both back & test cross

7.   Which of the Mendel's laws will always prove to be universally true in all cases?

     a) All three laws       b) Only the second law

     c) 2nd and 3nd laws            d) 1st and 2nd laws

8.  The types of gametes produced by a single heterozygous yellow wrinkled pea plant will be:

     a) Yr, yr                          b) YR, Yr, yR, yr

     c) TR, yR                       d) YR, yr

9.   When a dihybrid yellow round pea plant is  crossed with one of the parents, the progeny obtained is all yellow round only. What should be the genotype of the parent?

     a) YyRr                           b) YYRR

     c) YYRr                           d) yyrr

10. When a genetically dwarf pea plant is treated with gibberellin, it becomes as the genetically tall plant. Suppose this gibberellin treated tall looking pea plant is crossed with a genetic dwarf pea plant, the progeny will consist:

     a) 3 tall: 1 dwarf             b) 2 tall: 2 dwarf

     c) All tall only                   d) all dwarf only

11. Which one of the Mendel's laws is likely to be     non operative in case of closely linked genes?

        a) Law of dominance.   b) Law of segregation.

     c) Law of independent assortment 

     d) None of three 

12. How many different types of gametes can be formed by a pea plant with TtYyRr genotype?

        a) 6             b) 8           c) 4              d) 9

13.   In one of the crosses involving pea plants, A yellow round' was crossed with a 'green- wrinkled'. The progeny showed four different phenotypes in the ratio of 1:1:1:1 what can be the genotypes of the two plants respectively?

        a) YYRR and yyrr.         b) YyRr and yyrr   

     c) YYRr and                   d) yyrr and YyRr

14.   Mendel selected pea plants because:

        a) The seeds are edible 

        b) They were easily available.

        c) The plants were cheaper.  

        d) They were having contrasting forms of selected characters.

15.   If a cross involving a dihybrid produces a  progeny of four different phenotypes in equal ratios/proportions then it must be a 

     a) Dihybrid cross’s) Monohybrid test-cross.

     c) Dihybrid back cross.  d) Dihybrid test cross.

16. How many different types of gametes can be produced by an individual with YYRRtt genotype?

     a) 8   b) 4    c) 2     d) none of the above three

17.   A genotype 'AAbb' is rightly described as 

        a) Heterozygous.      

        b) Double heterozygous.

        c) Double homozygous.  

        d) Single homozygous.

18. Which of the following statements are correct?

        a) A homozygous always produces only one type of gametes.

        b) Each pair of heterozygous alleles produces two types of gametes

        c) The total number of different types of gametes that can be produces by a genotype is product of the types produced by each allelic pair in the genotype 

     d) All of these.

19.   If an individual possesses identical forms of a gene on identical gene loci of homologous chromosomes, it is described as

        a) Homozygous dominant

        b) Homozygous recessive 

        c) Homozygous                 d) Alleles

20. Two or more alternate forms of gene responsible for the expression of the same trait and situated on identical gene loci on homozygous chromosomes are called 

     a) Heterozygous   b) Homozygous 

     c) Alleles             d) recessive

21.   An individual having dissimilar alleles for a trait is described as a 

     a) Heterozygote                    b) Hybrid 

     c) Both a and b                    c) None of the above 

22.   In one of Mendel's experiments, two traits i.e. seed shape (round and wrinkled) and colour of cotyledons (yellow and green) were studied. In this experiment, he obtained a progeny showing four different phenotypes in the ratio of 9:3:3:1. What must be the produced such type of progeny?

     a) RRYY x rryy                     b) RrYy x RrYy     

     c) RRyy x rrYY.                            d) RrYy x rryy.

23.   In one of the Mendelian crosses, the progeny obtained contained four phenotype in following numbers.

        I) Yellow Round=2450 

        ii) Yellow Wrinkled=2550

        Iii) Green Round=2550 

        IV) Green Wrinkled=2450 

        a) Dihybrid F2 ratio.      b) Dihybrid test cross

        c) Dihybrid back cross d) both (b) & (c)

24.   The main reason for Mendel' success was that he:    

        a) Selected pea plants. 

        b) Used statistical principles to analyse the results. 

        c) Maintained statistical data meticulously. 

        d) First studied the inheritance pattern of one character at a time

25.   A cross is performed between two pea plants as follows (TTrrYY x ttRRyy). How many different types of phenotypes will be produced in the progeny of this cross? 

     a) 4.         b) 8.           c) 2.        d) 1.

26.   What will be the ratio of different types of   Gametes formed by a pea plant with YyRr?

     Genotype?

     A) 9:3:3:1. b) 1:1:1:1. c) 3:1 d)1:1

27.   A double heterozygous tall and yellow (cotyledon colour) pea plant is selfed. In the progeny obtained, what will be the ratio of homozygous dwarf and green offsprings?

        a) 1/4    b) 4/16     c) 3/16     d) 1/16

28.   In snapdragon, the Red flower colour shows incomplete dominance over white flower colour. In cross between pure Red and pure white parents, what will be F2 phenotypic and genotypic genotypic ratios respectively?

        a) Phenotype 3:1/genotype 1:2:1.

     b) Phenotype 2:2/genotype 2:2.

     c) Phenotype 1:2:1/genotype 1:2:1.

     d) Phenotype 3:1/genotype 3:1.

29.   An individual produces following types of 

     Gametes: (Abc), (Abc), (abc) and (abc), can be possible genotype of this individual?

        a) Aa Bb Cc.     b) Aa Bb CC.  

        c)Aa Bb cc.       d)AabbCc.

30.   Mendel first published his observation and conclusions about heredity and variations  based on the breeding expts on pea plants in the year:

     a) 1965.   b) 1901.   c) 1884.   d) 1866.

31.   "Law of segregation is applicable but not the law of independent assortment. “This can be possible in case of:

        a) Incomplete dominance. 

        b) A double homozygous recessive genotype.        

        c) Linked genes.

     d) All the above three

32.   Mendel's work was republished in the year:

     a) 1900.   b) 1884.   c) 1901.   d) 1866.

33.   Mendel selected seven characters (traits) in pea to study the inheritance pattern which one of the following was not in his list of the seven traits?

     A)Colour of cotyledons. b)Colour of seed coat

     c) Colour of pod.            d) Colour of flower

34.   In his experiment on pea plants, Mendel performed some of the crosses as follows:

                          Male parent         Female parent

         Cross -l   Yellow Round     Green wrinkled

         Cross -ll  Green wrinkled   yellow Round

        Such type of crosses are called :

        a) Test crosses.                 b) Back crosses.

        c) Reciprocal crosses.  d) Dihybrid crosses. 

35.   In Mendelian experiments, 1:2:1 ratio    represents the:

        a) Dihybrid test cross ratio. 

        b) Monohybrid test cross

        c) Dihybrid F2 ratio. 

        d) Monohybrid genotypic ratio

36.   All the genes located along the length of a chromosome represent a:

        a)Genome.            b) Gene compliment.

        c) Linear genes     d) Linkage group.

37.   Chromosomes were discovered by:

        a)Strasburger.  b) Morgan. 

        c) Punnett.       d) Mendel.

38.   The term 'gene' was first coined by:

        a) Mendel.                b) Johansen. 

        c) Strasburger.  d) Griffith

39.   The law of purity of gametes is also known as the

        a) Law of dominance.    

        b) Law of segregation.

        c) Law of independent assortment. 

        d) None of the above

40.   A tall pea plat with round seeds was crossed with a

     a)9:3:3:1.             b)All tall and round. 

        c)1:1:1:1.          d) b or c

41.   A double homozygous tall pea plant with green cotyledons is crossed with a pure dwarf plant with yellow cotyledons. The offsprings           are then crossed with dwarf and green pea plant. How many different types of phenotypes will be obtained in the resulting progeny?

     a) 1.    b) 2.      c) 4.    d) 16.

42. The genotypic and phenotypic ratio are identical in case of:

        a) Incomplete dominance. 

        b) Monohybrid test cross

        c) Dihybrid test cross.     

        d) All of these.

43.   If a tall pea plant is crossed with a dwarf pea plant, which of the following results can be possible in progeny obtained?

        a) All tall plants.   

        b) 1:1 phenotypic and genotypic ratio.   

        c) 3:1 phenotypic ratio.   

        d) Both a and b.

44.   If two pea plants, both with yellow cotyledon and round seeds are crossed, which of the following results can be possible?

        a) All yellow round only.  

        b) 12/16 yellow: 12/16 round  

        C) 9:3:3:1 ratio.        d) All of these

45.   In one of the Mendelian experiments, a pure round seeded pea plant was crossed with a pure wrinkled seeded plant. In the F2 generation of this cross, what will be the ratio of pure round: pure wrinkled?

     a) 3:1.     b) 1:1.   c) 2:2.    d) 2:1    

 


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