Question

5) Which of the following statements is true or false

a) “Traditional parasites”, such as members of the Class Trematoda and Class Cestoda of the Phylum Platyhelminthes, typically evolve increased virulence over evolutionary time.

b) In the course of evolution of the animal phyla, formation of the mesodermal coelom was responsible for the evolution of locomotion in Proterozoic multicellular eukaryotes (e.g., those responsible for the trace-fossils of burrows) because it provided a “hydrostatic skeleton” that muscles could contract against, where coelomic fluid pushes the anterior end of the animal forward when circular muscles contract.

c) If we establish that a barnacle which lives on the head of a whale can get more food by filter feeding (because it is transported rapidly through the water) than it would on a stationary substrate, and that the whale is not adversely affected, we can conclude that the barnacle has a “commensal” relationship with the whale.

d) Batesian mimicry is similar to “mutualism” in that both prey species (the mimic and the model) are benefited by the relationship.

e)“r selected” species usually have long lives, invest large amounts of energy in raising only a few well-cared-for young, and live in stable habitats with high diversity and strong biotic interactions between species; thus, they invest large amounts of energy in structural or other adaptations for increased effectiveness in biotic interactions with other species (e.g., predation, avoiding predation, and/or competition), and have high rates of population increase.

Answer 1

A. TRUE (Intrahost competition between parasite genotypes has been predicted to be an important force shaping parasite ecology and evolution which has been cited as a mechanism for the evolution of increased parasite virulence).

B. TRUE (Hydrostatic skeletons are the systems used by the animals for movement. The contraction of one set of muscles exerts a pressure on the fluid, which is forced to move at right angles. The movement of fluid stretches the other set of muscles, which can then contract to stretch its antagonist back to its relaxed position which results in an alternating change in the shape of the animal. Locomotion varies in crawling, burrowing, looping, or even walking).

C. TRUE (Barnacles use their sticky tentacles, gills, baleen plates to filter their food. In a commensal relationship where the barnacles are benefited greatly, the whales neither get benefited nor harmed for the relationship).

D. TRUE (Batesian mimicry refers to a theory where a harmless animal species gains protection because predators mistake it for the body type and leave it alone without consuming. Mutualism refers to the theory where both the organisms are benefited).

E. FALSE (r-selected species reproduce only a single time during their lifespan and requires less energy to reproduce. They produce many offsprings but only a few live out their full lifespan).