How will distinguish between natural and artificial fibres by observing the smell produced when burnt?​ its not biology it's chemistry

air enters through the nose, moves through the nasal cavity, the pharynx, the larynx, enters the trachea, moves through the bronchi andbronchioles till the alveoli.

refer to the attachment !

answer 1 : therefore:   crossing results in 50% (dominant homozygote) and 50% (dominant heterozygote).

answer 2 : therefore:   crossing results in 25% (dominant homozygote), 50% (dominant heterozygote) and 25% (homozygous recessive).

answer 3 : therefore:   crossing results in 100% (homozygous recessive).