Arthropods were the first terrestrial animals because their exoskeletons allowed them to withstand
A) the force of gravity.
B) ultraviolet radiation.
C) starvation.
D) high oxygen concentrations.
E) lower atmospheric pressure.
A
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The surface area of a plant's root system is substantially larger than the surface area of its shoot system. The extensive surface area of roots is an adaptation associated with _____
A) contact with soil particles for mineral and water absorption B) the internal structure of the vascular tissue in roots C) the storage of nutrients within the root system D) the release of carbon dioxide generated by photosynthesis
Which statement is true about speciation on island archipelagos?
A. Species clusters are less common. B. Speciation by polyploidy is most common. C. Ecological competition may cause new species to go extinct slowing speciation. D. Speciation is slow because it depends on emigration from the mainland. E. Most speciation occurs allopatrically.
Chemical reactions occur when substances undergo _________ to form new substances.
Fill in the blank(s) with the appropriate word(s).
Which feature does not occur in all living organisms?
a. All occur in living organisms b. Make and use organic molecules c. Consist of one or more cells d. Use DNA as their hereditary material e. Run the process of metabolism