Which of the following symbols and its representation is correctly used for constructing a human pedigree chart?

$A$ person may have one gene for normal haemoglobin and one gene for sickle cell haemoglobin. This heterozygous condition is called:

Which of the following statements are correct?
$(a)$ The $X$-linked genes are located on the non-homologous region of $X$-chromosomes.
$(b)$ Females with the recessive gene on one $X$-chromosome are carriers.
$(c)$ The carrier female is also severely affected by the disorder.
$(d)$ $Y$-linked genes are located on the homologous region of $Y$-chromosome.
$(e)$ Human males have homomorphic sex chromosomes.
Choose the correct option.

Which one of the following symbols and its representation,used in human pedigree analysis,is correct?

Consider the following statements regarding the $ABO$ blood group in humans:
$I.$ It is controlled by multiple alleles.
$II.$ It shows codominance.
$III.$ Codominance can be manifested phenotypically in humans.
$IV.$ It follows Mendel's law of inheritance.
Which of the following statement$(s)$ are correct?

What percentage of homozygous $Rh^{-}$ children will be born to a couple where the husband is heterozygous for $Rh^{+}$ and the wife is homozygous for $Rh^{-}$ (in $, \%$)?