1) Genes are not visible under the microscope but chromosomes are visible under the microscope.
2) Gene mutations are small, but chromosome mutations are large.
3) Genes are composed of either DNA or RNA, but chromosomes are composed of DNA, RNA AND Histones.
4) A single gene is a locus on chromosome, but a single chromosome compromises of many genes.
Hope this helped :)
Cool air rising through warm air
Endocasts of Homo erectus (left) and Homo sapiens (right) illustrate rapid increase in brain size. As early humans faced new environmental challenges and evolved bigger bodies, they evolved larger and more complex brains. Large, complex brains can process and store a lot of information.