VELAMMAL NEET & IIT ACADEMY
NUMERICALS ON GENETICS
1. Types of genotype observed in a dihybrid cross are
(a) 9
(b)12
(c) 4 (d) 6
2. In cross between yellow round (YYRR) and pure breeding pea plants having green
wrinkled (yyrr) find out the total seeds (plants) having yellow colour in F2generation
a) 12
b) 10
c) 14 d) 11
3. In cross between yellow round (YYRR) and pure breeding pea plants having green
wrinkled (yyrr) find out the total seeds (plants) having round seed texture
a) 12
b) 10
c) 9
d) 11
4. In cross between yellow round (YYRR)and green wrinkled (yyrr) find out the ratio between
seeds having yellow and green colour.
a) 3 : 2
b) 3 : 1
c) 9 : 7
d) 7: 9
5. In previous question find out the ratio between round and wrinkled seed texture
a) 3 : 1
b) 2 : 2
c) 1 : 1 d) 9 : 7
6. What is genotype ratio in a dihybrid cross?
a) 1 : 2 : 2 : 4 : 1 : 2 : 1 : 2 : 1
b) 2 : 4 : 2 : 1 : 2 : 1 : 1 : 2 :1
c) 1 : 4 : 2 : 1 : 1 : 1 : 2 : 1
d) 4 : 2 : 1 : 1 : 1 : 1 : 2 : 1 : 1
7. Total number of round seed in a cross between pure yellow round and pure green
wrinkled seeds in F2 is (out of total 16 resulted)
a) 9
b) 12
c)11
d) 10
8. Total number of wrinkled seed in previous question
a) 4
b) 3
c) 2
d) 1
9. The percentage of ‘ab’ gametes produced by ‘AaBb’ parent
a) 25
b) 50 c) 75 d) 12.5
10. In a dihybrid cross the ratio of pure double dominants and pure double recessive
individuals in F2 generation
a) 9:7
b) 1:9
c) 4:16 d) 1:1
11. Number of kinds of genotypes in F2 generation of Mendel’s dihybrid cross
a) 4
b) 9
c) 2
d) 1
12. Number of kinds of phenotypes in F2 generation of Mendel’s dihybrid cross
a) 5 b) 6
c) 8 d) 4
13. The number of kinds of gametes produced by a dihybrid is
a) 2 b) 4
c) 6 d) 8
14. In a Mendelian dihybrid cross kinds of recombinants formed in F2generation
a) 2
b) 4
c) 6
d) 10
15. Heterozygous round and yellow seeded pea plants were selfed and total 800 seeds are
collected. What is the total number of seeds with first dominant and second recessive
traits?
(1) 950
(2) 300
(3) 200
(4) 150
Sol. Answer (4). first dominant and second recessive means Rryy,RRyy.
16. Heterozygous tall and violet flowered pea plants were selfed and total 512 seeds are
collected. What will be total number of seeds for both heterozygous traits?
(1) 128
(2) 256
(3) 384
(4) 64
Sol. Answer (1)
17. In cross between pure breeding pea plants having yellow round (YYRR) and green wrinkled (yyrr)
seeds, find out the total seeds (plants) having yellow colour in F2 -generation.
(a) 12
(b) 10
(c) 14
(d) 11
18. In a cross between plants having yellow round (YYRR) and green wrinkled (yyrr) seeds, what will
be the ratio between seeds having yellow and green colour?
(a) 3 : 2 (b) 3 : 1 (c) 9 : 7 (d) 7 : 9
19. Total number of round seed in the F2 -generation of a cross between plants having pure yellow
round and pure green wrinkled seeds is
(a) 9 (b) 12 (c) 11 (d) 1
20. Ratio observed in dihybrid cross (phenotypically)
(a) 3 : 1
(b) 1 : 2 : 1
(c) 9 : 7
(d) 9 : 3 : 3 : 1
21. The number of different genotypes observed in the F2 -generation of a dihybrid cross are
(a) 9
(b) 12 (c) 4 (d) 6
22. How many types of gametes will be required for F2 generation of a monohybrid cross of Mendel
(1) 2
(2) 4
(3) 8 (4) 6
23. In a monohybrid cross, the genotypic ratio of offsprings is
(1) 3 : 1
(2) 1 : 2 : 1 (3) 1 : 1 : 1 : 1 (4) 4 : 0
24. A homozygous violet flowered pea plant .is crossed with homozygous white-flowered pea plant.
The offspring would be
(1) 50% violet flowered
(3) all pink flowered
(2) 50% pink flowered
(4) all violet flowered
25. A heterozygous round seeded plant is crossed to recessive wrinkled seeded plant. The progeny
would be:
(1) 20 rounded : 99 wrinkled
(2) 99 rounded : 301 wrinkled
(3) 301 rounded : 100 wrinkled
(4) 303 rounded : 301 wrinkled
26. A pure tall pea plant is crossed with pure dwarf pea plant. The progeny is self pollinated.
The ratio of true breeding tall pea plants to true breeding dwarf pea plants shall be
(1) 1 : 1
(2) 2 : 1
(3) 1 : 2
(4) 3 : 1
27. Pure red flowered and white flowered plants were crossed. It produced 120 offsprings with :
(1) All red flowered
(2) 90 white flowered and 30 red flowered
(3) 90 red flowered and 30 white flowered (4) 60 red flowered and 60 white flowered
28.In a cross 45 tall and 14 dwarf plants were obtained. Genotypes of parents were :
(1) TT × TT (2) Tt × Tt
(3) TT × Tt (4) tt× Tt
29. Gametes of AaBb individuals can be :
(1) Aa, Bb (2) AB, ab (3) AB, ab, aB (4) AB, Ab, aB, ab
30. In a dihybrid cross, pure homozygous plants will be :
(1) 9 (2) 3 (3) 4 (4) 1
31. Female AaBb is crossed with male AAbb. The gametes shall be :
(1) Female AB, Ab, aB and ab, male Ab
(3) Female AB, ab, Ab and aB, male AA, bb
(2) Female Aa, Bb, AB and ab, male Ab
(4) Female Aa and Bb, male Ab
32. From a cross AABb x aaBb, the genotypes AaBB, AaBb, Aabb, aabb will be obtained in the
following ratio
(1) 1 : 1 : 1 : 1
(2) 1 : 2 : 1 : 0
(3) 0 : 3 : 1 : 0
(4) 1 : 1 : 1 : 0
33. In a dihybrid cross AABB × aabb, F2 progeny of AABB, AABb, AaBB and AaBb occurs in the ratio of
(1) 1 : 1 : 1 : 1 (2) 9 : 3 : 3 : 1 (3) 1 : 2 : 2 : 4
(4) 1 : 2 : 2 : 1
34. Had Mendel decided to study those traits together which are determined by linked genes, he
would not have found out :
(1) Principle of segregation (2) Crossing over (3) Principle of independent assortment (4) Dominance
35. When two hybrids rrTt and Rrtt are crossed, the phenotypic ratio of offspring shall be :
(1) 1 : 1
(2) 9 : 3 : 3 : 1
(3) 3 : 1
(4) 1 : 1 : 1: 1
36. Tall red pea plant crossed to dwarf white plant yields only tall red plants. A test cross shall give a
ratio of :
(1) 1 : 1
(2) 1 : 1 : 1 : 1
(3) 3 : 1
(4) 9 : 3 : 3 : 1
37. How many different kinds of gametes can be produced by an organism of the genotype AaBBCc ?
(1) 3 (2) 4 (3) 9 (4) 8
38. Snapdragon flowers can be red (RR), pink (Rr) or white (rr). When red-flowered plants are
crossed to white flowered plants, the possibility of an F2 offspring being homozygous is :
(1) 1/4
(2) ½
(3) 3/4
(4) 1/12
39. How many genetically different gametes can be made by an individual of genotype AaBbccDDEe
(1) 5
(2) 8
(3) 10
(4) 32
40. If individuals of genotype AaBbCc are intercrossed, how many different genotypes can occur in
their progeny ?
(1) 6
(2) 8
(3) 16
(4) 27
41. In Andalusian fowls, if a cross is made between black fowl and splashed white, what will be the
phenotypic ratio in F2( black & white are pure lines,blue is intermediate)
(1) 1 : 1 : 2
(2) 2 : 1 : 1
(3) 3 : 1
(4) 1 : 2 : 1
42. Due to incomplete dominance, a cross between blue and white Andalusian fowl results in :
(1) 50% blue and 50% black
(2) 50% black and 50% white
(3) 50% white and 50% blue
(4) 75% black and 25% white
ANSWER KEY
1) 1
2) 1
3) 1
4) 2
5) 1
6) 1
7) 2
8) 1
9) 1
10) 1
11) 2
12) 4
13) 2
14) 2
15) 4
16) 1
17) 1
18) 2
19) 2
20) 4
21) 1
22) 1
23) 2
24) 4
25) 4
26) 1
27) 1
28) 2
29) 4
30) 3
31) 1
32) 4
33) 3
34) 3
35) 4
36) 2
37) 2
38) 2
39) 2
40) 4
41) 4
42) 3