The question is about a test cross. Definition of a test cross: Generally a cross involving a homozygous recessive individual. When a single trait is being studies, a test cross is a cross between an individual with the dominant phenotype but of unknown genotype (homozygous or heterozygous) with a homozygous recessive individual. If the unknown is heterozygous, then approximately 50% of the offspring should display the recessive phenotype. If the individual is homozygous all the progeny will have the dominant phenotype. James' suggestion to use show the result of the two possible crosses with a Punnet square is a great suggestion.
Answer:
The correct answer is A.
Explanation:
An osteoclast is large multinucleated cell present in the bone. Its main function is bone resorption, which occur when the osteoclasts secret hydrogen ions and many enzymes. As a result, bone matrix is digested by them. The most important enzyme is the protease cathepsin K, which degrades collagen.
Cathepsin K is regulated by parathormone, calcitonin and growth factor interleukin 6.
Matrix digestion is key during <u>bone fractures</u>, because it allows the repair and remodeling of the bone. But when this action is excessive, it can lead to osteoporosis (loss of bone density).
According to the nebular hypothesis,stars form in massive and dense clouds of molecular hydrogen—giant molecular clouds
<span>Herring gulls fiercely defend the areas around their nests in cliff-top breeding colonies. within the colony, they would show a uniform dispersion pattern.</span>
