Answer:
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water
Physical property is defined as the property of a substance which becomes evident during physical changes. Water is liquid at room temperature whereas hydrogen and oxygen are gases at room temperature.
Chemical property is defined as the property of a substance which becomes evident during chemical changes. Water reacts with metals to form bases, hydrogen reacts with metals to form hydrides and oxygen reacts with metals to form oxides.
My Answer: Vestigial organs
Why?: " Vestigial organs are physical structures that were fully developed
and functional in an ancestral group of organisms but are reduced
and unused in the later species."
Hope I helped! :D
B - store and transmit hereditary information