For obtaining a hybrid ratio,which characters of the plant are taken into account?

Choose the correct option regarding genetic disorders and inheritance patterns.

Match the terms in Column-$I$ with their descriptions in Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Dominance	$(1)$ Many genes govern a single character.
$(B)$ Co-dominance	$(2)$ In a heterozygous organism, only one allele expresses itself.
$(C)$ Pleiotropy	$(3)$ In a heterozygous organism, both alleles express themselves fully.
$(D)$ Polygenic inheritance	$(4)$ $A$ single gene influences many characters.

When the blood hemoglobin of a normal person and a sickle-cell patient is placed in an electrophoretic field,what will be observed?

Interspecific crosses are rare in nature and intergeneric crosses are almost unknown. Why?

Read the following statements carefully $:-$
$(a)$ Linkage is physical association of genes on a chromosome.
$(b)$ In $Drosophila$, genes of body colour and eye colour are tightly linked on $X$-chromosome.
$(c)$ In honey bee a fertilised egg develops as a male $(drone)$.
$(d)$ In grasshopper males have only one $X$-chromosome besides the autosomes.
$(e)$ $Drosophila$ can complete their life cycle in about two months.
Choose the correct option having all correct options.