Why did the dinosaurs become extinct?
A. A meteorite or comet crashed into the Earth, causing smoke and ash that blocked the sun and caused death of the plants that were food for dinosaurs.
B. The cycads upon which dinosaurs fed were purgatives and when they declined the dinosaurs, unable to digest flowering plants, died of constipation.
C. Increasing carbon dioxide levels produced climates too hot for the incubation of their eggs.
D. Increase in the number of ferns produced so many spores in the atmosphere that dinosaurs suffered from lung irritation.
E. The pollen produced by the rise in flowering plants produced allergenic responses in dinosaurs.
A. A meteorite or comet crashed into the Earth, causing smoke and ash that blocked the sun and caused death of the plants that were food for dinosaurs.
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You believe that an adult animal you are examining is a vertebrate but concede that it may be an invertebrate chordate. Which of the following would ensure that you are indeed looking at a vertebrate?
A) It is able to swim. B) It lacks a notochord. C) Its notochord functions as an endoskeleton. D) It uses its pharyngeal gill slits for respiration. E) It has a dorsal hollow nerve cord.
In addition to burning fossil fuels, humans return CO2 to the atmosphere faster than it can be removed by:
A. clearing forests for agriculture. B. polluting the oceans. C. generating nutrient pollution. D. expanding rice production. E. expanding beef production.
There are no algae that can cause human disease.
Answer the following statement true (T) or false (F)
Which of the following molecules coordinates the expression of nonadjacent genes?
A) leucine zippers B) response elements C) transcription factors D) coactivators E) control elements