Final Exam Biology - Fall 2024

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What is positive feedback in biological systems?

Back

Positive feedback is a process that amplifies or increases the output of a system. An example is childbirth, where the release of oxytocin increases contractions, leading to more oxytocin release.

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What are phospholipids?

Back

Phospholipids are a class of lipids that are a major component of all cell membranes. They consist of two fatty acids, a glycerol unit, and a phosphate group.

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What type of macromolecule is ATP?

Back

ATP (adenosine triphosphate) is classified as a nucleic acid, specifically a nucleotide, which serves as the primary energy carrier in cells.

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What percentage of energy is typically lost at each trophic level in an energy pyramid?

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Typically, 90% of energy is lost as heat or used by the organism for survival at each trophic level in an energy pyramid.

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What is activation energy?

Back

Activation energy is the minimum energy required for reactants to undergo a chemical reaction and form products.

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What is thermoregulation?

Back

Thermoregulation is the process by which organisms maintain their body temperature within certain boundaries, even when the surrounding temperature is different.

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What is the role of cholesterol in cell membranes?

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Cholesterol helps to stabilize the structure of cell membranes, making them less permeable to very small water-soluble molecules that might otherwise pass freely through.

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What is the function of enzymes in biological reactions?

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Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur.

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What is homeostasis?

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Homeostasis is the ability of an organism to maintain a stable internal environment despite changes in external conditions.

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What are carbohydrates?

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Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen, typically in a ratio of 1:2:1, and serve as a primary energy source for living organisms.