It is hypothesized that viroids evolved from

a) viruses.
b) exons.
c) introns.
d) prions.


Answer: c) introns.

Biology & Microbiology

You might also like to view...

Many antibiotics kill bacteria because they hinder translation by prokaryotic _____.  

A.  ribosomes B.  capsules C.  cytoskeleton D.  cytoplasm E.  nucleoids Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? · What key words does the question contain and what do they mean?   Gather Content · What do you know about translation? How does it relate to the question? Consider Possibilities · What other information is related to the question? Which information is most useful?   Choose Answer · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Reflect on Process · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Biology & Microbiology

The term N-terminus refers to the presence of a(n) ________ at the 5? end of a polypeptide.

A. oxygen atom B. carboxyl group C. amino group D. carbonyl group E. sulfate group

Biology & Microbiology

A specific type of cell is being studied by a scientist. She notices the cell contains a nucleus, lysosomes, a cell membrane and cell wall. What is the correct classification of this cell?

A. A prokaryotic animal cell B. A prokaryotic plant cell C. A eukaryotic animal cell D. A eukaryotic plant cell

Biology & Microbiology

Many scientists believe that we are in a global mass extinction caused by human activity. What is conclusive evidence for this assessment?

a. Current estimated extinction rates on islands are 10,000 times greater than background extinc-tion rates. b. Current estimated extinction rates on continents are 10,000 times greater than background ex-tinction rates. c. One genus of tropical butterflies lost 90% of its species during the past 30 years. d. Converting old-growth forest into agricultural fields causes dramatic losses in songbird diver-sity in the converted areas.

Biology & Microbiology