A heterozygous tall plant (Tt) was crossed with a homozygous

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A heterozygous tall plant (Tt) was crossed with a homozygous dwarf plant (tt). The resultant seeds were collected. If five seeds are chosen at random, then the probability (in %) that exactly two of these seeds will yield dwarf plants is ______.

1. 11%
2. 31%
3. 41%
4. 21%

Correct Option: B

The probability of dwarf seeds from resultant seeds = 0.5 = 50%
Then probability of selection of 2 seeds which yield dwarf plant from selected 5 seeds
By applying Binomial theorem

P =	n!	a^s b^t
	s! × t!

n = The total number of events
s = The number of times outcomes a occurs
t = The number of times outcomes b occurs
Therefore n = s + t

P =	5!			1		³	×		1		²
	3! × 2!			2					2

=	5 × 4		1	×	1	×	1	×	1	×	1
	2		2		2		2		2		2

P =	20
	64

% P =	20	× 100% = 31.25%
	64