Aphids are small insects that insert their mouthparts into a plant to obtain phloem sap. Which would be the best way to determine if aphids must actively draw phloem sap into their digestive tract or if hydrostatic pressure in the phloem tube could force
the sap into them?
A) Isolate a phloem tube from a plant, allow an aphid to insert its mouthparts, and see if the aphid can still take up sap from it.
B) Measure relative rates of sugar manufacture in leaves with and without aphids.
C) Insert mouthparts removed from an aphid, without including the digestive tract, into phloem sap and see if sap keeps flowing through them.
Answer: C
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While visiting the South Island of New Zealand, you notice that conditions vary sharply across the island. The West Coast is very wet and receives between 600 and 1600 mm of rainfall per year, while the East Coast only receives about 640 mm of rain per year and is very dry. What best explains this regional difference in precipitation?
A. Proximity to Antarctica. B. The absence of inland lakes. C. The presence of a large river along the West Coast. D. The presence of mountains along the West Coast. E. Latitudinal differences between the East and West Coasts. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? Gather Content · What do you already know about precipitation? 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?
Which of the following is not a way in which RecA activity is regulated?
A. transcription of the RecA gene B. autoregulation C. regulation by binding of other proteins D. regulation by other proteins that block RecA binding; for example, single-strand binding proteins (SSB) E. translation of the RecA protein
Blood collected from a victim at a crime scene contains 30% adenine. A short distance away, a knife is found with traces of blood containing 20% thymine. What conclusion can you make based on this evidence?
a. The blood on the knife belonged to the killer. b. The blood on the knife belonged to the victim. c. Further DNA sequencing is required. d. The knife was not the murder weapon.
What enzymes are used to cut DNA molecules? How do they work?
What will be an ideal response?