Question

A pure tall plant bearing red colour flowers was crossed with a pure dwarf plant with white flowers. [5 MARKS]
(a) What would be the nature of offsprings in the F1 generation?
(b) If the offsprings of the F1 generation are self-pollinated, what would be the ratio of red flowers to white flowers in the F2 generation?
(c) What can you infer from the ratio obtained in (b)? Which law does it illustrate?

Answer 1

a) 1 Mark
b) 2 Marks
c) 2 Marks

(a)

Offsprings in the F1 generation will be heterozygous tall with red colour flowers.

(b)

In F2 generation, the ratio of red flowers to white flowers will be 3:1.

(c) We infer from the ratio obtained in (b) that there is no blending of characters, i.e., the flowers are either red or white. Red and white do not blend to produce pink flower. It illustrates the law of segregation which states that.
"From a pair of contrasting characters (alleles) only one is present in a single gamete and one character is dominant and the other recessive in 1, and in 2, these characters segregated in the ratio of three to one."