18. Which of the following species would be most likely to survive if a nearby (
ID: 232174 • Letter: 1
Question
18.
Which of the following species would be most likely to survive if a nearby (~7000 light years) GRB happened with its beam toward Earth?
Select one:
A. humans
B. phytoplankton
C. sea urchins - which begin life as a planktonic larva
D. a deep-sea anglerfish
19.
Which extinction on Earth might have been due to a GRB?
Select one:
A. 250 Myrs ago: The Permian-Triassic Event
B. 205 Myrs ago: The Triassic-Jurassic Event
C. 360 Myrs ago: The Late Devonian Event
D. 65 Myrs ago: The Cretaceous-Tertiary (KT) Event
E. 450 Myrs ago: The Ordovician-Silurian Event
20.
What is the evidence for a GRB causing a mass-extinction on Earth?
Select one:
a. An increased abundance of muons found in fossils with an age of about 250 million years.
b. Air bubbles from Antarctic ice cores show a depletion of the ozone layer 65 million years ago.
c. Strange, gamma-ray mutated life-forms present in the fossil record.
d. There is no direct evidence. It is suggested by the pattern of death in a mass extinction matching that expected to be caused by a GRB.
e. A spike in the abundance of iron-60 found in rocks dating back 450 million years ago.
Explanation / Answer
18) C. sea urchins - which begin life as a planktonic larva
larva were more likely to cover a broad geography, but they were more likely to go extinct during this time
19) E. 450 Myrs ago: The Ordovician-Silurian Event
Gamma-ray burst may have caused one of the five greatest mass extinctions on Earth, such as the Ordovician extinction that occurred 440 million years ago