Describe the three most common routes by which chemicals enter the body and subsequently interact with cells.
In: Biology
1. How does penicillin act on a bacterial cell - or stated another way - what is the mechanism of action of penicillin? what is the cellular target of the antibiotic?
2. Why does penicillin not act on human cells? or stated another way - why does penicillin have selective toxicity?
3. Be specific about why the penicillin may be able to act differently on one type of cell. What about that one type of cell allows penicillin to act more effectively?
In: Biology
Conventional wisdom dictates that a low-fat diet rich in fruits, vegetables, and grains keeps you “heart healthy,” yet low-carbohydrate, high fat diets are popular for weight loss (which increases heart health) and for reducing problems associated with diabetes. Research and discuss both sides of the argument in an APA paper with a minimum of 350-word.
In: Biology
Anthropologists believe that, several million years ago, our ancestors colonized an ecological niche different from the one occupied by the other African apes. Label the lettered parts of your answer. A. What is the unique hominin niche? B. What aspects of the hominin niche have fostered large brains? C. What is altriciality and what might have favored it in the human lineage?
In: Biology
Sexual reproduction is an evolutionary puzzle. Label the lettered parts of your answer. A. Why is sex a puzzle; what are its costs? Don’t merely list them; describe how each is a cost. B. According to the Red Queen model, what benefits might compensate for these costs? C. Some previously sexual species have reverted to asexuality; according to the Red Queen model when should that happen? Explain.
In: Biology
In: Biology
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Predict what would happen to the carbon cycle if plants were not a part of it. Provide an explanation for your prediction.
In: Biology
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Name the four processes of the nitrogen cycle and describe what happens in each process.
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Define the term carrying capacity. Explain the reason every environment has a carrying capacity.
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Explain how fossils provide evidence for the process of evolution.
In: Biology
Describe how changing one amino acid in an enzyme could affect the function of that enzyme. Be sure to include in your answer how this change could affect the various levels of protein structure and function. Be specific with a concrete example of the change e.g. hydrophobic amino acid for a hydrophilic amino acid, or an ionic amino acid for a neutral amino acid. (Terms you want to include in your answer- active site, lock and key model or induced fit model- i.e. how does change in 3-d structure effect function of the enzyme).
In: Biology
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Describe two ways that humans have contributed to the extinction of different species.
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How did the evolution of photosynthesis alter the course of evolution. Please be at least 7 sentences and be descriptive about how it changed evolution.
In: Biology
Are sex chromosomes only found in germ cells (i.e., gametes or sex cells)? Explain.
In: Biology