Answer: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.
Answer:
500
Explanation:
According to the given information, the total number of albino people in the population= 1000/4 = 250.
Since albinism is an autosomal recessive trait, the genotype of albino people would be homozygous recessive. Therefore, the frequency of homozygous recessive genotype in the population (q2) = 250/1000= 0.25.
The frequency of recessive allele (q) = square root of 0.25 = 0.5
Since p+q=1. So, p (frequency of dominant allele) = 1-q = 1-0.5 = 0.5
Frequency of heterozygotes in the population= 2pq = 2 x 0.5 x 0.5 = 0.5 or 50%
Therefore, expected number of heterozygotes in the given population= 50% of 1000 = 500
During it’s metamorphosis
Answer:
Population growth, rising incomes, and more time = more animals.
Explanation:
that layers of sediment were originally deposited horizontally under the action of gravity