The correct answer is A.
Toxins and various pollutants increase in concentration through the food chain in a process called biomagnification. This means that the organisms on the top of the food chain, like the herring gull, have many times greater concentration of toxins than the lower food chain level organisms because they prey on lower food chain level organisms. If a herring gull ears 100 herrings, it will have a 100x times greater concentration of toxins in its body than a herring.
Answer:
membrane and everything else inside is considered the cell, it can be said that it is a single cell. Then, the chicken egg deserves its reputation as the largest cell. If, however you consider the yolk and the albumen (the egg white), separate structures, then eggs are not a single cell.
Explanation:
Short answer: One ovum = one cell = single cell (Latin: unam cellulam), from which we get uni-cellular. ... The zygote resulting from a successful fertilization of a single egg cell (a living unicellular organism), by a single sperm cell (also a living unicellular organism), is also a living unicellular organism
Anton van Leeuwenhoek :-))
The RNA world hypothesis states that the earlier life-forms had relied only on RNA (Ribonucleic Acid) for the purpose of catalyzing the chemical reactions, and storing the genetic information. This hypothesis was proposed by Leslie Orgel, Carl Woese, and Francis Crick.
This hypothesis states that long before the living forms evolved to use DNA as the genetic storage material, the RNA molecules served the purpose of both storing the genetic information and carrying out catalysis, but because of its instability, DNA evolved.
Hence, the answer is RNA world hypothesis.
