Answer:
The answer is 'B'- There is already soil present.
Explanation:
One of the biggest difference between primary succession and secondary succession is that primary succession occurs where there is zero availability of soil. In case of secondary succession, an already established community gets hampered due to <em>man made</em> activities or natural disasters like <em>flood, rain</em>, etc.
Since there is soil present in his farmland and vegetation is also available, it is the process of secondary succession.
Answer:
The correct answer is option (D) "His- strain grows on an his- plate".
Explanation:
The Ames test is a procedure that allows to detect if a given compound can cause mutations on a tested organism by growing strains of bacteria that require histidine (His-) to growth, since they are not able to produce its own histidine. In the Ames test, the bacteria is exposed to a given compound and is grown in a medium with small amount of histidine (his- plate). If the His- strain grows on a his- plate, it means that the bacteria has mutated to synthesize its own histidine and it is considered as a positive result on a the Ames test.
Both were powerful nations and they served as trading hubs in their respective regions during that time.
Answer:
During METAPHASE the chromosomes line up along the equatorial plate.
