What does it mean when there is variation within a species?

Which type of neuroglia is found outside of the brain?

Classify the structures as homologous or analogous, depending on their structure and function.

Food webs - transferring energy and matter from one level to another. here you see four food webs. one or more are incorrect. which food web(s) show the correct sequence of organisms, from start to top level consumer? a) a b) d c) c d) a and d