Question 61pts Mass extinctions remove dominant groups of organisms and thus provide new ecological

Question 61pts Mass extinctions remove dominant groups of organisms and thus provide new ecological and evolutionary opportunities for groups of organisms that were previously of little importance. These organisms can then fill the now existing niches through the process of ___________.directed mutationmitosiscloningadaptive radiationFlag this QuestionQuestion 71pts Which kind of organism makes up the oldest fossil found on Earth?protistsbacteriaanimalsplantsFlag this QuestionQuestion 81pts The Cambrian explosion resulted in the evolution of more than 17,000 species of an animal known as the trilobite. The shear number of trilobite fossils found in modern times suggests that trilobites were very abundant, perhaps the rulers of the seas. Today, no living descendants of this group exist. What happened?In order to disappear from the planet entirely, trilobites must have undergone the process of adaptive radiation.It is unlikely that trilobites could have survived the increase in atmospheric oxygen once the process of photosynthesis had evolved.Being so plentiful, trilobites must have been the major food source for terrestrial dinosaurs. The extinction of the trilobite may have caused the mass extinction of dinosaurs.Because trilobites evolved before the first mass extinction, it is possible that one or more of the five mass extinctions could have eventually wiped out the entire group.Flag this QuestionQuestion 91pts The first land plants ____________.grew from the seeds of marine plantsevolved from green algae that could already carry out photosynthesiswere descendants of fungi that developed photosynthesiswere ferns and small shrubs