Ptolemy's model was Geocentric. This means that it put the earth at the center of the solar system, instead of the sun, with all celestial objects orbiting it. The first person to prove the validity of the heliocentric theory was Nicolaus Copernicus.
Is the answer computer because that can be used for both
4: a species is a group of interbreeding natural populations that are reproductively isolated from other such groups. Process of Speciation. The process of speciation is a 2 stage process in which reproductive isolating mechanisms arise between groups of populations.
You can check how fast your heart is beating.
Crossing over
Independent assortment
