Which purine base forms 3 hydrogen bonds when binding its complementary nucleotide base?

A. uracil
B. cytosine
C. thymine
D. guanine
E. adenine


Answer: D

Biology & Microbiology

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Which of the following statements describes a eukaryotic chromosome?

A) a single strand of DNA B) a series of nucleosomes wrapped around two DNA molecules C) a chromosome with different numbers of genes in different cell types of an organism D) a single linear molecule of double-stranded DNA plus proteins

Biology & Microbiology

Why do plants growing outside often have shorter and thicker stems than plants of the same species grown indoors?  

A.  The plants inside have a more constant source of light and therefore a higher level of phytochrome. B.  The outdoor plants are subject to mechanical stresses and they are exhibiting a thigmomorphogenic response. C.  The outdoor plants are subject to touch by animals and other plants and are exhibiting a thigmotropic response. D.  The indoor plants have elevated levels of auxin and are therefore taller than the outside plants. 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 already know about growth of protected vs. exposed plants? 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 nonselective movement of water and a number of solutes into excretory system tubules is called --____

a. reabsorption b. excretion c. filtration d. secretion e. diffusion

Biology & Microbiology

Which substance is not a biofuel? a. Alcohols b. Gases c. None of these are biofuels

d. All of these are biofuels. e. Oils

Biology & Microbiology