The question is incomplete as it does not have the options which are:
I. only
I. and II. only
II. and III. only
I, II, and III.
Answer:
I, II, and III.
Explanation:
The mechanism of natural selection can be explained for the trait which is determined by one gene but the traits which can be determined by more than one gene like height (polygenic trait), the selection becomes very complex.
The natural selection can be explained by the phenotype produced in a population and that depends on the genes. The polygenic trait shows the variation in the population, therefore, it is impossible to predict only one mechanism and therefore all types of natural selection occurs on a population.
Thus, I, II, and III are correct.
An organic molecule will always contain CARBON.
The correct option is A.
An organic molecule or compound refers to a chemical entity in which one or more atoms of carbon are bonded covalently with atoms of other elements. Because of the number of valence electron that carbon possess, it has the capacity to form different types of chemical bond with different types of elements.
Bones are made up of Calcium Phosphate given by the chemical formula, 
. When bones are kept in Hydrochloric acid, given by the chemical formula, HCl, they become soft because the calcium compound present in the bones changes its form. The following double displacement reaction takes place when the bones are kept in HCl,
---> 
Calcium chloride is water soluble, and gets washed away. This makes the bone thin and soft.
Answer:
Label A is the amino group
Label B is the R group
Label C is the carboxyl group
Explanation:
