Imagine that you are a graduate student seeking an idea for a research project that will help us understand the evolution of a parasitic lifestyle from a free-living lifestyle. Which of the following outcomes would you expect if you compare the genes of parasitic species to relatives that are free living?
A) The parasitic species will have fewer functioning genes than the free-living species because loss of many genes will not be harmful.
B) The free-living species will have more functioning genes because they evolved new traits.
C) The genes will have changed in base sequence, but the number of functioning genes in parasitic and free-living species will be the same.
D) More genes for sensing the environment will have evolved in the parasitic species as compared to the free-living species.

Question

Quizplus · Accepted Answer

Parasitic species typically have a reduced genome and undergo gene loss due to their reliance on hosts for energy and resources. Many of the lost genes are essential only in a free-living lifestyle, so they are not necessary for parasites to survive. Therefore, parasitic species will have fewer functioning genes than free-living species.

Imagine That You Are a Graduate Student Seeking an Idea