Indian Institute of Technology, Guwahati

• COMPUTER S 456

• 1. Question 1 Parasites live in the environment of their hosts’ bodies, which constantly change in order to respond to the actions of the parasite. Based on this information and what you learned in the videos, would you hypothesize that most parasites reproduce sexually or asexually? 1 point Asexually, because sexual reproduction will be slower in variable environments, and it is beneficial for parasites to reproduce as quickly as possible Sexually, because sexual reproduction produces more varied offspring and thus a higher chance that at least some of the offspring will have the genes needed to survive Sexually, because sexual reproduction will be faster in variable environments, and it is beneficial for parasites to reproduce as quickly as possible Asexually, because there is less of a chance of mutations occurring with asexual reproduction, and mutations will make it difficult for parasites to survive in variable environments 1. Question 1 Which of the following scenarios would reduce the action of Muller's ratchet in asexual organisms? 1 point if advantageous mutations occurred more often in sexual than asexual organisms if asexual organisms reproduced more quickly than sexual organisms if the name were changed to Muller's screwdriver if "back-mutations" of detrimental mutations to their original, good, form were very common 2. Question 2 You are studying a beneficial allele that has undergone strong positive selection to fixation. Is it possible to have a neutral allele near this variant hitchhike along with it, but, unlike the beneficial allele, not go to fixation? 1 point Yes- but only if it is in a species that reproduces asexually No- alleles that are close to the variant that goes to fixation will be linked, and thus always undergo a selective sweep to fixation