Question

Why are traits acquired during the lifetime of an individual not inherited in the next generation?

Answer 1

because. these changes generally occurs in the somatic cells of the organism not in the genes which carry the information for making proteins that is why the trait acquired during lifetime of an organism dies with the organism

Answer 2

this is a clear example of Mendles experiments stating traits can be dominant or recessive...
the traits acquired by the F1 progeny as dominant and show in its phenotype may be reslcessive in the F2 progeny and do not show in that organisms phenotype...