Answer: D
Explanation: I had the same question
Answer:
The correct answer is "secondary succession, an ecological succession step where an area previously occupied by living beings is disrupted".
Explanation:
In ecological succession, an ecosystem changes and develops through a series of steps. The first step, is the primary successional stage where rocks or other sedimentary structures are colonized by microorganisms. The second step, where the ecosystems changes towards a relatively-stable mature stage, occurs when an area previously occupied by living beings is disrupted. This step is named secondary succession, and the most clear example of this phenomena occurs when wildfire clears oak and hickory forests.
Answer:
A. Yes, because the %A approximately equals the %T and the %G approximately equals the %C in both species.
Explanation:
According to Chargaff's rule, in all cellular DNAs, the number of adenosine residues (A) is equal to the number of thymidine residues (T). And the number of guanosine residues (G) is equal to the number of cytidine residues (C). Therefore, the sum of the purine residues equals the sum of the pyrimidine residues (A+ G= C+ T). It is based on the fact that a purine base always pairs with a pyrimidine base in a double helix DNA.
Chargaff’s rule is followed in all the double-helical DNA molecules irrespective of the species. In DNAs of sea urchin and salmon, the percentage of adenine is equal to that of the thymine and the percentage of guanine is equal to that of the cytosine. Therefore, Chargaff's rule is followed.
Proteins have many important roles in cell function like structural support, biocatalysts, receptors.