Observe the given picture and identify a representative pedigree shown in the give picture ?

Autosomal recessive trait .

The correct answer is Option (2) – Autosomal recessive trait .

 Autosomal recessive trait (example : sickle -cell anaemia ).

Sickle-cell anaemia :  This is an autosome-linked recessive trait that can be transmitted from parents to the offspring when both the partners are carrier for the gene (or heterozygous). The disease is controlled by a single pair of allele, Hb^A and Hb^S. Out of the three possible genotypes only homozygous individuals for Hb^S (Hb^SHb^S) show the diseased phenotype. Heterozygous (Hb^AHb^S) individuals appear apparently unaffected but they are carrier of the disease as there is 50 per cent probability of transmission of the mutant gene to the progeny, thus exhibiting sickle-cell trait.