Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation?

#Question id: 8931

#Section 2: Evolution

#Question id: 8935

#Section 2: Evolution

#Question id: 11401

#Section 2: Evolution

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leafʹs nonliving, waxy covering, while inhibiting the growth of

other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, it causes a fatal disease in the plant. Once the plant dies, the bacterium

and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Use only those that

apply.

1.  nutrient recycler          2.  mutualist            3.  commensal              4.  parasite          5.  primary producer

#Question id: 11402

#Section 2: Evolution

How can prokaryotes be considered to be more successful on Earth than humans?

#Question id: 11499

#Section 2: Evolution

Biologists have long been aware that the defunct kingdom Protista is paraphyletic. Which of these statements is both true and consistent with this conclusion?

#Question id: 11500

#Section 2: Evolution

The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following?