An is made of different tissues and has a specific function.

Organs are structures made up of two or more tissues organized to carry out a particular function, and groups of organs with related functions make up the different organ systems.

Explanation:

hope it helps

a, i am pretty sure.

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.