Page 59 - Biology - XII

Q12. Which is dominant—Round or Wrinkled seeds in pea?
Ans. Round seeds

Q13. How many traits did Mendel study?
Ans. Seven traits in a pea plant.

Q14. What is the Mendelian ratio (Phenotypic) of round seeds in F generation of a dihybrid cross?
2
Ans. 9 : 3 : 3 : 1.
Q15. What does the law of dominance mean/state?
Ans. It states that out of the two contrasting factors representing a character in a hybrid, only one trait
expresses itself in the F generation.
1
Q16. What is phenotype?
Ans. The external appearance of the individual’s trait is called phenotype.
Q17. How many are pure recessive in 9:3:3:1?
Ans. Only 1

Q18. Give your understanding on law of independent assortment.
Ans. This law states that the inheritance of one factor is independent of the inheritance of the other factor.
Q19. Mention the Mendelian ratios (phenotypic) for mono and dihybrid crosses.
Ans. Monohybrid phenotypic ratio—3:1
Dihybrid phenotypic ratio—9:3:3:1

Q20. Give a suitable reason to call G.J. Mendel as the Father of Genetics.
Ans. G.J. Mendel is called the Father of Genetics because he was the fi rst to propose the law of
inheritance.

COMPETENCY BASED QUESTIONS

Multiple Choice Questions

Q1. The cotyledons of a pea seed may be
(a) yellow (b) green (c) both (a) and (b) (d) none of these

Q2. The trait not studied in Mendelian traits is
(a) pod length (b) fl ower colour (c) pod colour (d) (a), (b), and (c)

Q3. Best season to study Mendelian inheritance ‘Live’ in fi elds in India is
(a) winter in Northern India (b) summer in Southern India
(c) any season (d) rainy season in India

Q4. Broad categories of traits of a pea plant for inheritance studied by G.J. Mendel were
(a) stem character (b) pod character (c) seed character (d) (a), (b) and (c)
Q5. Total number of Mendelian traits studied is

(a) 5 (b) 6 (c) 7 (d) 8
Q6. The position of pod on the stem of a pea plant is
(a) axial (b) terminal (c) axial and terminal (d) no position

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