For him they were just discrete physical units of inheritance. Johanson coined the term "gene" and people started calling them genes. Today for us these factors are parts of DNA, the base sequences that carry the biological information to determine a trait. Mendel factors are alleles of genes.
False, only some . Hope this helps !
"C. Organisms' characteristics are carried
<span> on DNA.</span>" would be the best fit, although this still isn't really the core idea behind natural selection, which is that animals survive based on how "fit" they are for their environment.
Cells are the basic unit of life and they are the 1st level of organization. The heart is the 3rd level. They are separated by 1 level, tissues.