How many species of animals havebeen extinct?

What happens if you try to use the coarse adjustment when the 10X lens is in place

Polygenic inheritance is determined by multiple located at different loci on different chromosomes

Abiotic and biotic factors of a river / bank

Suppose an environmental change that causes the soil color to become much different occurs in both environments. Which of the following is true?

A researcher is trying to construct a molecular-based phylogeny of the entire animal kingdom. Assuming that none of the following genes are absolutely conserved, which of the following would be the best choice on which to base the phylogeny?

How do fish nets effect the ocean's ecosystem?

A dog and a pig attempt to mate. we are aware that these are two different animal species. but what is the best explanation for the barrier that makes it impossible for them to successfully mate?

How do fossils and fossil record support the idea that life changes over time

1 reason why cases of violence and abuse are not reported

Question number 3 Site A is pavement. Site B is bare soil. Site C is a forest. Soil erosion caused by runoff will be greatest at Site be greatest at Site