Some don't have any able to see effects,but some cause diseases
Answer;
-Pure chemical substance and element
Explanation;
-Pure substances are substances that are made of only one type of atom or molecule.A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary.
-An element is a pure substance that cannot be broken down into different types of substances by chemical means. All elements are pure substances. An element is composed of a single kind of atom. An atom is the smallest particle of an element that still has all the properties of the element.
-Tungsten is an element and therefore a pure substance.
Ss would represent the hybrid. Pure genes are PP hybrid would would be Pp
Answer: Human evolution, the process by which human beings developed on Earth from now-extinct primates. Viewed biologically, we humans are Hono Sapines, a culture-bearing upright-walking species that lives on the ground and very likely first evolved in Africa about 315,000 years ago.