Answer:
In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium was also growing in some of the dishes. A clear area existed around the mold because all the bacteria that had grown in this area had died. In the culture dishes without the mold, no clear areas were present.
Fleming thought that the mold must be producing a chemical that killed the bacteria. He decided to isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he removed it from the nutrient broth. Fleming then added the nutrient broth in which the mold had grown to a culture of bacteria. He observed that the bacteria died. He also added the same type of broth that had not been exposed to the mold, to a culture of the same type of bacteria. Nothing happened to the bacteria.
Explanation:
n 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium was also growing in some of the dishes. A clear area existed around the mold because all the bacteria that had grown in this area had died. In the culture dishes without the mold, no clear areas were present.
Fleming thought that the mold must be producing a chemical that killed the bacteria. He decided to isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he removed it from the nutrient broth. Fleming then added the nutrient broth in which the mold had grown to a culture of bacteria. He observed that the bacteria died. He also added the same type of broth that had not been exposed to the mold, to a culture of the same type of bacteria. Nothing happened to the bacteria.
Answer:
C.
Explanation:
In section 18 the elements are the most stable because they complete themselves without having to share electrons with other elements. Does that make sense?
Answer: Genetic Change
Explanation:
Mutations contribute to genetic variation by causing new traits to emerge. Mutations happen when there is a change in the DNA of a creature developing in utero. These random changes in creatures are common, although most mutations end up being lethal or inhibiting to the organism. In rare cases, this mutation can prove benificial or helpful, and if the organism reproduces and the trait is passed along, it could become a new branch of genetic variation within the species.
It reduces
Explanation:
The density of the heated mantle rock reduces because its volume has increased.
- Frictional heat, heat from radioactive decay and heat that accretted originally when the earth was forming are responsible for heating the mantle.
- When a substance is heated, it expands and its volume increases.
- Density is a function of mass and volume.
- The higher the volume, the lower the density.
- The higher the mass, the higher the density.
- When the mantle is heated, its volume increases to a new one and its density reduces.
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Density brainly.com/question/12450480
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