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sammy [17]
3 years ago
5

in the early days of antibiotic use , penicillin and sulfonamide were used to successfully treat a variety of bacterial infectio

ns . in later years stronger antibiotics were needed because some bacteria were either resistant to or not affected by these same antibiotics . this situation is best explained ?
Biology
1 answer:
Vladimir [108]3 years ago
8 0
This situation is best explained by the process of natural selection.
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Kathy was making liquid growth medium for plants. The pH of the original solution was 8. The optimal pH for plant growth is 6. W
liubo4ka [24]

If referring to the question: Kathy was making liquid growth medium for plants. The pH of the original solution was 8. The optimal pH for plant growth is 6. What was the best compound to add to make it pH=6?

A) KOH

B) HCL

C) Water

D) No answer provided

Then the correct answer would be option B, to add HCL, known as Hydrochloric acid to lower the pH to 6.

In science, pH is a scale used to measure the acidity of a solution or its basicity. The scale ranges from 0 to 14. A pH of 7 would mean that the given solution is neutral, lower than 7 equates to an acidic solution, while anything above 7 becomes increasingly basic.

Option A is to add KOH, or potassium hydroxide to the original solution whose starting pH is 8. KOH is a solution whose pH is above 8,  a strong base, and is often used to increase the pH of a solution. In the question it states what the desired pH is 6, therefore we want to lower, not increase the pH. This makes option A incorrect.

Water is a neutral solution. Even though it is neutral, it is not used to neutralize basic or acidic solutions. Acid or bases may be added to water to create very diluted solutions that are nearly neutral despite containing a strong base or acid, but this is a different process than neutralization and will not give the desired pH. Option C is also wrong.

Option B is correct because HCL, known as hydrochloric acid is a strong acid, commonly used to lower the pH of a solution by increasing the concentration of hydrogen ions. Since we start with a pH of 8 and wish to achieve a pH of 6, HCL is the correct component to add to the solution. Due to option B being correct, option D that states that no answer is provided, is incorrect.

For more on pH visit:

brainly.com/question/491373?referrer=searchResults

8 0
3 years ago
How are gymnosperm seeds and angiosperm seeds different?
Novay_Z [31]

Answer:

angiosperms have seeds that are closed within an ovary, gymnosperms have no flowers or fruits, and have unenclosed seeds on the surface of scales or leaves

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Name two organs that are easy to repair using stem cells. What are two organs that are difficult to repair using stem cells?
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The skin and the liver are two organs that would be easy for stem cells to repair. What would be difficult to repair would be the apical meristem and the lateral.
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When the oxyhemoglobin curve shifts during exercise what is the result?
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It releases bound oxygen into your body's tissues.
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Which plants can survive in both water and soil?
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Tulips can survive in water and in soil
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