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A student investigates phototropism in wheat seedlings. She cuts the tips off some of her seedlings. She leaves the seedlings in the window. Two days later the seedlings have bent towards the light. Describe and explain these findings.

removing tips removes auxin so growth stopsauxin collects on the shaded sideauxin causes cell elongation on the shaded sideelongation on one side causes shoot to bend to the other sidethis is positive photot...
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Answered by Amina A. • Biology tutor
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Explain the lock and key model of enzyme action, including how they are denatured.

An enzyme is a protein that functions as a biological catalyst by speeding up chemical reactions and remaining unchanged by the reaction. The place on an enzyme where the molecule binds is called the active ...
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Answered by Lucy Erin S. • Biology tutor
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Describe how a vaccine results in immunity.

Vaccine contains dead or altered/weakened form of the disease-causing pathogen, which contains a specific antigen . The antigen stimulates an immune response , leading to production of B lymphocytes . Activa...
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Answered by Dide O. • Biology tutor
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a) What is the function of the atrioventricular valves? b) When the ventricles are contracting, are the arterioventricular valves open or closed? c) Explain why the muscle walls of the atria are thinner than the walls of the ventricles.

a) To prevent backflow of blood from the ventricles into the atria.b) Closedc) The atria only have to pump blood into the ventricles, where as the ventricles have to pump blood at a high pressure all the way...
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Answered by Catherine O. • Biology tutor
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How would you test for the presence of glucose?

You gently heat the mixture and add 2-3 drops of Benedict's solution.If glucose is present, the solution will turn from blue to orange.
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