Which of the following is a purine?

A) guanine
B) cytosine
C) thymine
D) uracil
E) cysteine


A) guanine

Biology & Microbiology

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Mycorrhizae are the mutualistic relationship between fungi and the roots of certain plants.

Answer the following statement true (T) or false (F)

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What basal transcription factor is most often affected by regulatory transcription factors?

A. TFIIB B. TFIID C. TFIIE D. TFIIF

Biology & Microbiology

What would happen to a plant that is treated with a chemical that prevents electrons from moving through the electron transport chain?

A. It could no longer produce CO2. B. Water would be broken down to form oxygen at a higher rate to compensate. C. It could not generate an electrochemical H+ gradient across a membrane. D. It could not produce NADP+. E. More electrons would be available for the light harvesting array.

Biology & Microbiology

The relatively simple excretory system used by flatworms consists of tubules called

a. nephrons. b. hepatic tubules. c. metanephridia. d. Malpighian tubules. e. protonephridia.

Biology & Microbiology