Answer:
There will be 12 chromosomes
Explanation:
We have given that The epithelial cells in the skin of an animal have 24 chromosomes
We have to find the number of chromosomes present in the gametes of this animal
We know that number of chromosomes present in the gametes is given by

So number of chromosomes in gametes 
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.
The answer is orange because the way that he said the problem out.
Answer:
B = hydrogen bonding
Explanation:
The water molecule consist of two hydrogen atom one oxygen atom. There is large electronegativity difference between oxygen and hydrogen. Both atoms are bonded through covalent bonds.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial negative. The partial positive end of one water molecule attracted towards the partial negative end of other moleucle. The attraction between them is called hydrogen bonding. In this way large mole are connected with each other. Hydrogen bonding is actually a weak bonding.
A single piece of coiled DNA is called a plasmid.