Tuesday, March 13, 2012

GENETICS-ASSIGNMENT

1 Among the following identify the Pea plant with only dominant characters.




Ans:Inflated green pods developed from axillary flowers
2 Arrange the following plants of Pea in a sequence of recessive to complete dominant features.
I. Short plants with rounded seeds, green cotyledons and Grey testa
II. Tall plants with wrinkled seeds, green cotyledons and Grey testa
III. Yellow ripe pods, yellow cotyledons, round seeds and white testa
IV. Green ripe pods with yellow cotyledons, round seeds developed on tall plats





Ans:II, I, III, IV
3 Total number of Pea varieties collected by Mendel was




Ans:34
4 Mendel’s experimental results were not confirmed by




Ans:Boveri
5 The term Genetics was given by




Ans:Bateson
6 Choose the correct statements
I. Mendel was the first to perform hybridization experiments
II. Mendel was the first person to consider the results of hybridization in terms of single traits.
III. Mendel counted and classified the progeny resulted from crosses in pea plants
IV. Mendel compared the proportions of his hybridization results with mathematical models.





Ans:all except I
7 [A]: Mendel identified Pea plants as suitable to carry out hybridization experiments
[R]: Pisum sativum has bisexual flowers that naturally cross fertilised





Ans:A is true but R is false
8 Select the correct characters shown by Pisum sativum
I. It is Annual
II. It can be grown and handled easily
III. It produces larger number of offspirings
IV. It has well defined characters





Ans:I, II, III, IV
9 Mendel’s experimental results were published as




Ans:Experiments in Plant hybridisation
10 Choose the correct statements with respect to Monohybrid crosses
I. Tall plants of parental generation do not have allele ‘t’.
II. Tall plants of F1 generation do not have allele ‘t’.
III. The plants of F2 generation without the allele ‘t’ and with only ‘t’ alleles exist in 1:1 ratio.
IV. The ratio between the tall plants of F2 and F1 generation is 3:4.





Ans:I, III, IV
11 Individuals of the following genotypes are not seen in P and F1 generations during dihybrid cross




Ans:TT rr
12 The assumptions made by Mendel through his experiments were sustained by the discovery of




Ans:Meiosis
13 Study the following table and choose the correct combination





Ans:All except II
14 In Mendels dihybrid cross F2 individuals with the following genotype are formed in 1:1:1:1 ratio




Ans:rr yy, rr YY, RR YY, RR yy
15 Arrange the following crosses in a sequence of gradual increase in the number of offspring with the genotype Rr Yy
I. Rr YY X rR yY
II. RR yy X rr YY
III. Rr YY X Rr Yy
IV. rr YY X RR Yy





Ans:III, I, IV, II
16 In the following crosses all the individuals formed will be having similar genotype
I. RR YY X rr yy
II. rr YY X RR yy
III. Rr YY X RR Yy
IV. Rr Yy X RR YY





Ans:I, II
17 Match the following





Ans:A - II, B - V, C - IV, D - I
18 Plants with similar forms of alleles on homologous chromosomes are




Ans:Dwarf pea plants
19 The ratio between the F2 plants of dihybrid cross with homologous and non-homologous alleles for both the traits is




Ans:1:1
20 When monohybrid crosses are made in Pea plants, the following fail to appear in F1 generation




Ans:Plants with terminal flowers
21 [A]: All F1 plants of Monohybrid cross are tall
[R]: F1 hybrids have the allele ‘t’.





Ans:Both A and R are true but R is not the correct explanation of A
22 Number of types of gametes formed by pea plant with genotype as AA, Tt, Yy, Rr is




Ans:8
23 Study the following with respect to Monohybrid cross and identify the suitable match





Ans:A - V, B - IV, C - II D - I
24 If a cross is made between between the pea plants with the genotypes as Rr Yy and rr Yy, the pea plants with the following genotypes can not be formed
I. rr yy
II. Rr YY
III. RR yy
IV. RR Yy





Ans:III and IV
25 In a dihybrid cross, the ratio between the phenotypically similar individuals of F1 and F2 generations is




Ans:16:9
26 Match the following





Ans:A - V, B - IV, C - II, D -I
27 Out of 16 outcomes of an event , in how many out comes there is formation of Mendelian recombinants in F2 generation of Dihybrid cross.




Ans:6
28 Choose from the following where the probability is 1/4.
I. Formation of gametes in F1 dihybrid with allele RY.
II. Formation of dwarf plants in F2 generation of Mendelian Monohybrid cross.
III. Formation of wrinkled seeds in F2 generation of Dihybrid cross.
IV. Formation of Round green seeds in F2 generation of Dihybrid cross.





Ans:All except IV
29 2Arrange the following crosses with gradual increase in the probability of formation of Round and yellow seeded plants
I. Ry Yy X rr yy
II. rr Yy X RR yy
III. RR Yy X RR Yy
IV. Rr Yy X RR YY





Ans:I, II, III, IV
30 Choose the set with mutually exclusive genotypic outcomes of an event for the formation of yellow seeds




Ans:YY ; Yy ; yY
31 Choose the crosses that show the probability of formation of heterozygous Yellow seeded plants is 1/2.
I. YY X Yy
II. Yy X Yy
III. yy X Yy





Ans:I, II, III
32 The probability of formation of yellow round seeded plants in F2 generation of dihybrid cross which do not show the genotype Yy Ry is




Ans:5/16
33 By using the probability law, this is the correct explanation for the formation of F2 individuals of dihybrid cross with the genotype rr Yy




Ans:1/4 X 1/2
34 This is the correct explanation for the probability of obtaining F1 generation plants of Dihybrid cross with Yy Rr genotypes




Ans:1 X 1
35 Choose the genotypes of Mendel’s dihybrid cross whose probability in F2 generation is 1/2.




Ans:None
36 In a trihybrid cross, what is the probability of obtaining plants with the genotype RR Tt yy in F2 generation




Ans:1/4 x 1/2 x 1/4
37 Study the following table and choose the correct combinations with respect to Mendel’s dihybrid cross





Ans:I and III
38 [A]: The probability of formation of F2 individuals of dihybrid cross with the genotype Rr YY is 1/8.
[R]: The probability of formation of F2 individuals of Monohybrid cross with genotype Rr is 1/4 and with YY is 1/4.





Ans:A is true but R is false
39 When a heterozygous sweet pea plant with blue flowers and long pollen grains is test crossed , The progeny will not be having the following genotype




Ans:RR r0r0
40 Chromosomal maps that show linked genes were prepared by




Ans:T.H. Morgan

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ASTHRA JUNIOR COLLEGE , VIJAYAWADA