1- A male who diagnosed with cystic fibrosis will be
represented in pedigree
by:
.
• A) Full shaded circle.
B) Full shaded square.
C) Half shaded circle.
D) Not shaded square.

pls help me quick

I believe that this is the best answer

ExplanationB) Full shaded square.

D

Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.