Have developed circulatory systems to transport materials. unicellular multicellular both a and b none of above

Name the following: (a) category of pathogen that causes diseases, like common cold and mumps. (b) the microorganism that requires a host to produce.

Which type of bond forms between water moleculesstrong bondhydrogen bondcovalent bondpolar bond

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important