What is an appropriate definition of an evolutionary trade-off?

What is the basis of antigenic variation in Trypanosoma brucei (sleeping sickness agent)?

Consider this published phylogenetic tree of HIV-1 (Human Immunodeficiency Virus) strains M/A, M/B, N and O, and several SIVcpz strains (Simian Immunodeficiency Virus of chimpanzees). Don’t mind the colors. Which of the following is an accurate statement of relationships?

Which of the following verbs would be suitable as a signal verb?

Which of the following is recommended for formatting a Reference page?

In APA writing, which is the preferred font:

In APA formatting, the page where sources are listed is called the _______________________ page.

The RUNNING HEAD contains

Margins for the APA paper are

A title page is not used in __________________ formatted papers.