Answer:
A DNA barcode is a short, standard gene segment of an organism that has been identified in a gene bank, used to identify unknown species by comparison with the DNA sequence of the gene bank. .
I’m pretty sure it’s physical
A Refrigeration system helps keep foods fresh for a longer time and it also helps to keep the food from collecting bad bacteria.
It’s called a solar system because solar means “relating to or determined by the sun” and system means “a set of things working together as parts of a mechanism or an interconnecting network” and the solar system is a whole bunch of planets and other things that are related to the sun and working together.