Fill in the following blanks with suitable words :
(a) Genes always work in ................ .
(b) In pea plants, the gene for dwarfness is ............... Whereas that for tallness is .............. .
(c) Most people have ............ earlobes but some have ............... earlobes .
(d) A human gamete contains ........... chromosomes whereas a normal body cell has ............... chromosomes in it.
(d) All races of man have ........... blood groups .
(f) The .............. chromosomes for a ............. are XX whereas that for a ............. are XY .