Question

What would be the proportion of dwarf plant with pink flowers if a heterozygous tall plant with pink flower is test crossed?

• A. $\frac{4}{16}$
• B. $\frac{6}{16}$
• C. $\frac{3}{16}$
• D. $\frac{1}{16}$

Answer 1

The correct option is A $\frac{4}{16}$

• Test cross is done to know whether a dominant trait showing organism is heterozygous or homozygous for that trait. It involves crossing of an organism with another organism which has homozygous recessive alleles for that trait.
• Punnet's square for the cross is shown below, where T/t and P/p are dominant/recessive alleles for height and pink flower respectively.
  

  	TP	Tp	tP	tp
  tp	TtPp	Ttpp	ttPp	ttpp

• As we can see, dwarf plants with pink flowers ( shown by ttPp ) are 1/4th or 4/16th in proportion.

So, the correct option is '4/16'.