The correct answers are as follows:
1. A.
There are basically two types of succession, they are primary and secondary succession. Primary succession refers to the type of succession that occurs in new and bare areas where the soil present is unable to sustain the growth of plants. An example of primary succession area is an area with sand dunes that is freshly formed. Primary succession usually occur over a long period of time. Secondary succession is a type of succession that occur on a land which was disturbed by hazardous events such as fire outbreak, flood, etc. Secondary succession occurs much faster than the primary succession.
2. D
There are two types of factors that affect any particular ecosystem, these are abiotic and biotic factors. The abiotic factors refers to non living factors such as temperature, relative humidity, rainfall, etc. while the biotic factors refer to the living factors. Looking at the options given above, one will see that only option D has living factor, which is predators. All other options have abiotic factors.
Answer:
B. 20%
Explanation:
The complementary base-pairing rule states that Adenine always pairs with Thymine (A with T), and Cytosine with Guanine (C with G).
Because of this, the amount of Adenine present must be the same as the amount of Thymine present, and the same for Cytosine and Guanine.
This means that if there is 30% Adenine, there is also 30% Thymine as each A base is paired to a T base. This adds to 60%, so Cytosine amounts and Guanine amounts must add to 40% to make 100%.
Since they are equal in amount, there must be 20% of each.
Therefore the answer is B. 20%
There is 30% Adenine, 30% Thymine, 20% Guanine and 20% Cytosine.
Hope this helped!
The correct answer is all of the above
