How many species of organisms are estimated to inhabit the Earth

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!

If there is another new infectious disease somewhere in the world, what do you think canadian officials should do

Ts assignment - snow day assignment genetic variation and natural selection natural selection relies on genetic variation. in any population of beetles, there are alleles for brown or green color. what happens to the genotype and the phenotype of the beetle population when there are distinct advantages and disadvantages due to color? order the steps that take place during natural selection in this beetle population.