"<span>The genes for melanin pigmentation remain turned on and prepare more melanin than usual to protect the skin from photo-damage when it is exposed to sunlight for long time" is the actual reason. </span>
The likelihood that the first two offspring of the cross will have congenital analgesia would be 1/16
<h2>Autosomal Recessive Traits</h2>
For autosomal recessive traits, two recessive alleles are needed for the trait to manifest while one recessive allele means heterozygosity.
In this case, let us assume that congenital analgesia is represented by the allele b; heterozygous individuals will, thus, be Bb.
Bb x Bb
BB Bb Bb bb
Probability of producing unaffected offspring = 3/4
Probability of producing affected offspring = 1/4
Likelihood of the first two offspring having congenital analgesia = probability of first having congenital analgesia and the second having congenital analgesia
= 1/4 x 1/4
= 1/16
More on genetical probabilities can be found here: brainly.com/question/851793?referrer=searchResults
Answer:
Persistent depressive disorder.
Persistent depressive disorder, known as dysthymia or low-grade depression, is less severe than major depression but more chronic. It occurs twice as often in women as in men. Persistent depressive disorder (PDD) is a serious and disabling disorder that shares many symptoms with other forms of clinical depression.
B. Positive feedback, it decreases body temperature.