Which secretion is not a barrier that prevents pathogens from entering the body?

Based on their location in the atmosphere, the layers are able to have their own special characteristics. for example, most weather occurs in the troposphere. what occurs in each of the other layers? (site 1)

One function of the poly-a tail on eukaryotic mrna sequences is to the mrna be transported from the nucleus to the cytoplasm. prokaryotic mrna also has a poly-a tail. choose the best explanation of the prokaryotic poly-a tail. a. prokaryotic poly-a tails have the same functions as eukaryotic poly-a tails, because this process is highly conserved throughout different species. b. prokaryotic poly-a tails aren't important, because prokaryotes don't have nuclei. c. prokaryotic poly-a tails have other functions, because prokaryotes don't have nuclei. d. prokaryotic poly-a tails are composed of a different molecular structure compared with eukaryotic poly-a tails.

How had the study of mitosis affected scientists knowledge of cancer