Question

In sweet pea plants, the presence of dominant C and P genes is essential for the development of purple colour. The ratio of plants producing flowers of different colours in the progeny of the cross CcPp x Ccpp will be

• A. 2 white and 6 purple coloured flowers
• B. 2 purple and 6 white coloured flowers
• C. 3 white and 5 purple coloured flowers
• D. 3 purple and 5 white coloured flower

Answer 1

Answer: (D)

3 purple and 5 white coloured flower

In this case, both the dominant genes C and P has to be present to express purple flower colour.
Cross between CcPp X Ccpp :

	CP	Cp	cP	cp
Cp	CCPp (Purple)	CCpp (White)	CcPp (Purple)	Ccpp (White)
cp	CcPp (Purple)	Ccpp (White)	ccPp (White)	ccpp (White)

It gives 3 purple and 5 white colored flowers.