The answer is competition.
Competition is an interaction between organisms. If resources, such as food, water, sunlight, territory, are limited and several species depend on these resources, then, they must compete with other species to gain the resources. So, if predators are present, this means that they will maintain the size of prey population on some optimal level. With fewer individuals in the population, there will be less competition for resources.
Therefore, <span>In natural ecosystems, the presence of predators lessens the effects of <u>competition</u> among the prey.</span>
The answer is 1 because the nucleus contains the DNA of eukaryote, and the other answers seem to be referring to the cell membrane or cell walls.
Operons are gene regulatory mechanisms that involve promoting and repressing genes that are involved in the metabolism of organic substances (i.e. sugars). Living organisms have the innate ability to metabolize glucose as the main source of energy. Although, in the absence of glucose, the organism must "learn" to use sugars other than glucose (such as lactose) in order to survive.
For instance, in the <em>lac </em>operon:
In the absence of glucose, various regulatory proteins promote the transcription of the gene related to the metabolism of lactose. This will ultimately lead to the production of the enzyme beta lactosidase which will enable the organism to use lactose as energy in the absence of glucose. This will therefore increase the chances of the organism for survival and will be naturally selected for evolution.
Hydrochloric acid is a strong acid (fully dissociates when dissolved in water due to the polar covalent bond)
It is a very stable molecule
It is highly reactive with metals and with oxidising agents such as organic materials, alkalis, water etc.
Can be extremely corrosive if solution is concentrated.