Page 60 - Biology - XII

Q7. In Northern India during the winter, we fi nd many varieties of peas in the market. Why?
(a) These are imported varieties. (b) These are hybrid varieties.

(c) These are indigenous varieties. (d) Both (b) and (c).
Q8. Which genotype is a hybrid?
(a) YYRR (b) YYrr (c) Both (a) and (b) (d) None of these

Q9. What does this representation—Yy Rr mean in a dihybrid cross?
(a) Yellow round (b) Green round (c) Yellow wrinkled (d) Green wrinkled

Q10. The F phenotypic ratio of a dihybrid cross that follows Mendel’s laws is
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(a) 9 : 6 : 1 (b) 9 : 7 (c) 9 : 3: 3: 1 (d) none of these
Q11. Which position of fl ower is dominant in pea plants?

(a) Terminal (b) Anywhere (c) Base (d) Axillary
Q12. According to Mendelian trait, the stem length is categorised as

(a) T (b) t (c) Tt (d) T, t
Q13. Pod character studied in Mendelian inheritance by Mendel are
(a) pod shape—infl ated and constricted (b) pod colour—green and yellow

(c) pod length—long and short (d) both (a) and (c)
Q14. Seed character/traits for a pea plant studied by Mendel in his inheritance experiments were

(a) seed shape—round and wrinkled (b) cotyledon colour—yellow and green
(c) coat colour—grey and white (d) (a), (b), and (c)

Answer key
1. (c), 2. (d), 3. (a), 4. (d), 5. (c), 6. (c), 7. (d), 8. (d), 9. (a), 10. (c), 11. (d), 12. (d), 13. (d), 14. (d)

Assertion-Reason Type Questions

These consist of two statements—Assertion (A) and Reason (R). Answer these questions by selecting
the appropriate option given below:

a. Both A and R are true and R is the correct explanation of A.
b. Both A and R are true, but R is not the correct explanation of A.
c. A is true, but R is false.
d. A is false, but R is true.

1. Assertion (A) : In the dog fl owers, F plants produce pink fl owers.
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Reason (R) : It is due to codominance of fl ower colour alleles with both genes expressing
themselves equally.
2. Assertion (A) : A test cross is used to determine the phenotype of an organism.

Reason (R) : F generation of a monohybrid test cross produces one or two phenotypes
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depending upon the genotype of the unknown organism.
Answer key

1. (c), 2. (d)

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