Explanation:
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females.
The physical appearance of a trait is called the phenotype of an organism.
<span>When the microscope was invented, it helped the cell theory. This invention allowed scientists to see that everything was made up of cells and see what cells do. They needed this invention in order to see that cells existed and study them more in depth.</span>
The smallest and most exclusive grouping category is species.
