a. parsimony; simplest; fewest
When selecting among multiple possible phylogenetic trees that fit our data, we commonly use the principle of <u>parsimony</u>, which means we choose the <u>simplest</u> possible hypothesis. In phylogenetic analysis, that means selecting the tree that represents the <u>fewest</u> evolutionary changes or mutations.
Explanation:
Phylogeny describes the evolutionary history of on organism or group of organisms.
A phylogenetic tree structure is used to describe the relationship between various organisms which have originated from common ancestors.
The Principle of Parsimony is best applied while constructing phylogenetic tree.
This principle emphasizes on simple observations on a phylogeny which requires only few changes or variations which explain for the difference between the phylogenic sequences.
This tree structure will only have few specific genetic variations or mutations or evolutionary changes which took place through new appearance of a trait or disappearance of an existing trait.
The answer is the last one: amoebas, yeasts, hydras, and ferns
After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Homogeneous is the answer
