Tossup

A species of these organisms that act as pests in one ecosystem are injected with bile salts using autonomous drones like RangerBot. A relaxin-like peptide hormone found in these organisms called “gonad-stimulating substance” makes them a useful model to study oocyte maturation. They aren’t deer, but two recent studies have disproved the theory that the densovirus (-5[1])SSaDV caused a mysterious “wasting disease” in these (10[1])organisms. (-5[2])The (-5[1])Triton Snail is one of the few (-5[1])natural predators capable of containing outbreaks (-5[1])of a corallivorous type of these animals in the genus (10[2])Acanthaster. (-5[1])Studying the (10[1])purple (10[1])Pisaster (10[4])genus (10[1]-5[1])of these animals (10[1])in rocky intertidal ecosystems (10[1]-5[1])led Robert (10[1])Paine (-5[1])to coin the term “keystone species.” (10[2])For 10 points, what echinoderms are named (-5[1])for having five arms? (10[1])■END■ (10[13])

ANSWER: starfish [or sea stars; accept Asteroidea; accept specific species like purple sea star or common sea star or crown-of-thorns sea star; accept Acanthaster planci until read; prompt on Asterozoa; prompt on echinodermata; reject “brittle stars”]
<Carnegie Mellon A, Biology>
= Average correct buzz position

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Buzzes


Summary

TournamentEditionTUHConv. %Neg %Average Buzz
California2025-02-013100%67%102.33
Florida2025-02-013100%0%101.00
Midwest2025-02-016100%50%110.17
Overflow2025-02-015100%40%105.20
Pacific Northwest2025-02-012100%50%112.50
South Central2025-02-012100%0%116.00
Southeast2025-02-013100%33%112.67
UK2025-02-015100%40%104.80