A Punnett square for a cross involving 2 genes (each with 2 alleles) has 4 rows and 2 columns.
True or False?

In a Punnett square for a cross is involving 2 genes (each with 2 alleles). In F1 generation, it will bear 2 rows and 2 columns .  But in F2 generation the punnett square will have 4 rows and 4 columns ( like Mendel's law said). The genotype ratio in F1 generation is 1:2:1 and phenotype ratio is 3:1. so the  answer is false.  

Explanation:

if 2 genes Aa and Aa {which have 2 alleles (A,a and a,A)} do cross, then it will give,

              A     a

       A   AA    Aa

        a   Aa    aa

from the above, punnett square it is proved that it will bear 2 rows and 2 columns.

the most common energy conversion is from kinetic energy to potential energy, and then from potential energy to kinetic energy.

later on comes the heat energy, mechanical energy, and other energy conversions.

this energy conversion is so common that we can find it in our day to day lives as well.

- one of the most common energy conversions involves the changing of potential energy to kinetic energy or kinetic energy to potential energy