Homogeneous is the answer
Answer: B. Water breaks down into oxygen molecules for respiration.
Water is the required for photosynthesis, a process by which plants (terrestrial and aquatic) makes their food by utilizing water as a reactant to produce oxygen and glucose as product. The glucose act as a source of energy for conducting various metabolic processes in plants but oxygen is released in the air.

This oxygen is necessary for terrestrial and aquatic animals for respiration. Therefore, water breaks down into oxygen by the process of photosynthesis, hence water plays important role in respiration in living beings.
Answer:
Contains large polytene chromosome that permit visual inspection of genomic events.
Were used to study the genetic effects of mutations.
Were used to establish the concept of chromosomal inheritance.
Explanation:
<em>Drosophila melanogaster </em>is a model organism that is used by scientists to study the genes and effect of a mutation on the genes. Drosophila is used as a model organism as it has a very short life cycle and the offspring can be produced in a short duration of time.
Because of these characteristics, Thomas Hunt Morgan wanted to study the factors of inheritance on the <em>Drosophila</em> and concluded in the form of the chromosomal theory of inheritance by the effect of mutation on genes that lead to linkage mapping.
Also, the salivary gland of fruit fly contains the polytene chromosome which allows us to look into the gene events.
Thus, the selected options are correct.
It is The multicellular part