In human males,all the chromosomes are paired perfectly except one. These unpaired chromosomes are:
$(i)$ Large chromosome
$(ii)$ Small chromosome
$(iii)$ $Y-$ chromosome
$(iv)$ $X-$ chromosome

$(a)$ Distinguish between homologous and analogous organs.
$(b)$ State one evidence of organic evolution.

The genotype of a green-stemmed tomato plant is denoted as $GG$ and that of a purple-stemmed tomato plant as $gg$. When these two are crossed:
$(i)$ What colour of stem would you expect in their $F_1$ progeny?
$(ii)$ Give the percentage of purple-stemmed plants if $F_1$ plants are self-pollinated.
$(iii)$ In what ratio would you find the genotypes $GG$ and $Gg$ in the $F_2$ progeny?

All human races,such as Africans,Asians,Europeans,Americans,and others,might have evolved from a common ancestor. Provide a few pieces of evidence in support of this view.

An individual can pass on to its progeny the experiences of its lifetime.

Farmers selected swollen parts of wild cabbage and developed the variety known as ..........