Bio 148 EXAM 3 NEWEST ACTUAL EXAM ALL QUESTIONS AND CORRECT ANSWERS|ALREADY GRADED A+

Bio 148 EXAM 3 NEWEST ACTUAL EXAM ALL QUESTIONS AND CORRECT ANSWERS|ALREADY GRADED A+ Positive Interaction - Answer- mutualisms, commensalism mutualisms - Answer- interactions where both species benefit Commensalism - Answer- one organism benefits and the other is unaffected symbiosis - Answer- a particular type of mutualisms where one species lives in close physical association with the other (either mutualism(+./+) and parasitism (+/-) true - Answer- parasites control the hosts' mind Ectomycorrhizal fungi - Answer- grows around root cells; arbuscular mycorrhizal fungi - Answer- can grow into the root cells too Mycorrhiza - Answer- used to describe the symbiotic rls between mycorrhizal fungi and a plant's root system benefits of fungi - Answer- some can provide energy and nutrients in both partners; energy in exchange for nutrients; or energy to one only in exchange for a service - some provide habitat for the other in exchange for a service or for free obligation - Answer- the interaction must happen for the two species to survive/grow/reproduce; the species can evolve adaptations that make the interaction more likely and increase the benefit to the other species facultative - Answer- the interaction is not necessary for the species to survive and reproduce; Same facultative interactions can happen with lots of species (e.g., nurse plants, seed dispersal) example of obligate - Answer- figs and pollinating wasps The wasp gets: A safe, nutritious place to lay its eggs The fig gets: - Its pollen from other figs delivered to its flowers - Nutrients from the dead wasps example of facultative - Answer- seed dispersal Plant seeds are often adapted to attach themselves to passing animals or to passing through animals example of how mutualisms are prone to cheating - Answer- Cheating is when a "mutualist" gets the benefits without paying the cost Species have mechanisms to limit cheating Yucca plants and yucca moths are another reproductive mutualism What are the wider effects of mutualisms? - Answer- Mutualism directly increase survival & reproduction If bacterial symbiont is missing, then the fly's reproductive success plummets when challenged by worm parasites Mutualism increases population abundance If you take the ants away, the trees are 14x smaller, had lower survival rates (43% vs. 72%), and were attacked by more herbivores, usually die in 6-12 mo. ants dont survive without trees! Mutualism impacts community richness Cleaners eat about 1200 parasites a day from 2300 clients; parasites increase 4x after only 12 days without Parasite - Answer- a symbiont that consumes the tissues or body fluids of the organism it lives in. unlike carnivores, they do not immediately kill the organisms they eat. Effects on host vary from nuisance to lethal host - Answer- the organism that a parasite lives in/on Ectoparasite - Answer- a parasite that lives on the outside of its host Endoparasite - Answer- a parasite that lives on the inside of its host Pathogenicity - Answer- a parasite that causes disease in its host Parasitoid - Answer- insects whose larvae feed on a single host and almost kills it Endoparasite examples - Answer- Enters through and lives in the G-I tract, which is great habitat to live in Parasites in here, generally don't eat the host, just its food Some live in host's tissues or cells: Yersinia pestis, plague bacterium Mycobacterium tuberculosis, Tb bacterium Coronavirus SARS-CoV2 Advantages of living in or on a host Ectoparasitism: - Answer- dispersal easier, safer from host's immune system disAdvantages of living in or on a host - Answer- feeding more difficult, greater to external environment, greater vulnerability to natural enemies Advantages of living in or on a host Endoparasitism - Answer- feeding easier, more protection from external environment disAdvantages of living in or on a host Endoparasitism - Answer- dispersal more difficult, greater vulnerability to host's immune system host defenses - Answer- immune system & biochemical defenses Immune system in a host - Answer- Has specialized cells to recognize microparasites it has been exposed to before; in many cases, leads to lifelong immunity Immune system can encapsulate endoparasites Plants produce antibacterial and antifungal compounds to protect themselves Biochemical defenses - Answer- - idea is to reduce parasite survival and growth by starving them - vertebrates have a protein (transferrin) that removes iron so efficiently from areas where parasites can use it that it impedes growth - animals (caterpillars, chimps) start eating poisonous plants when they have parasites defensive symbionts - Answer- bacteria or fungi that prevent colonization by parasitic species Life cycle of the malaria parasite - Answer- Plasmodium has hundreds of genes that modify red blood: Some genes transport proteins to be placed on red blood cell surfaces to transport nutrients Others direct production of knobs that stick to other cells, preventing them from reaching the spleen; varied proteins on the knobs make it difficult for the immune system to detect