• Genetics of Comb Types in Domestic Fowl (Bateson and Punnett, 1905):
• Comb inheritance is governed by two independent interacting autosomal gene pairs ($R/r$ and $P/p$):
• Walnut Comb: $R\_ P\_$ (presence of both dominant alleles, e.g., $RRPP, RrPp$)
• Rose Comb: $R\_ pp$ (dominant Rose, homozygous recessive for pea, e.g., $RRpp, Rrpp$)
• Pea Comb: $rr P\_$ (homozygous recessive for rose, dominant Pea, e.g., $rrPP, rrPp$)
• Single Comb: $rr pp$ (double homozygous recessive)
• Conclusion: The genotype $Rrpp$ expresses the Rose comb phenotype.

Correct option: (2) Rose

• Primary Plumage Color Determination (Extension Locus):
• In domestic chickens, the primary feather color pattern across body regions is controlled by the Extension ($E$) locus on chromosome 1.
• Allelic Series at $E$ Locus:
• $E$: Dominant Extended black (uniform solid black plumage)
• $E^R$: Birchen (black with silver/gold lace on hackle and breast)
• $e^b$: Brown (wild-type female partridge pattern)
• $e^+$: Wild-type (black-breasted red / Red Junglefowl pattern)
• $e^y$: Recessive wheaten
• Other Loci: Secondary patterning genes (barring $B$, silver $S$, mottling $mo$) superimpose patterns over the base established by the $E$ locus.

Correct option: (3) E

• American Class of Poultry (Standard of Perfection):
• Breeds belonging to the American Class were developed in the United States and Canada as dual-purpose birds (meat and brown-shelled eggs), characterized by yellow skin, clean (non-feathered) shanks, and red earlobes:
• New Hampshire (developed in New Hampshire from Rhode Island Red)
• Rhode Island Red (RIR)
• Plymouth Rock (Barred / White Rock)
• Wyandotte
• Other Classes: English class (Australorp, Sussex); Mediterranean class (White Leghorn); Asiatic class (Brahma, Cochin).

Correct option: (3) American

• Incubation Periods Across Avian Species:
• Pigeon: $17\text{ days}$ ($17\text{--}19\text{ days}$).
• Comparative Incubation Periods:
• Chicken: $21\text{ days}$
• Japanese Quail: $17\text{ days}$
• Duck: $28\text{ days}$ (except Muscovy duck: $35\text{ days}$)
• Turkey: $28\text{ days}$
• Goose: $28\text{--}32\text{ days}$
• Ostrich: $42\text{ days}$

Correct option: (1) 17 days