The strongest component of the cell wall<span> is a carbohydrate called cellulose, a polymer of glucose. The </span>cell wall gives rigidity<span> and strength to the </span>plant cells<span> which offers protection against mechanical stress. ... The </span>rigidity<span> of primary </span>plant<span> tissues is due to turgor pressure and not from rigid </span>cell walls<span>.</span>
Answer:
The hardness rating is 4.
Explanation:
Calcite sits at a hardness rating of 3 and is very easily scratched with a knife and/copper coin. This is where most Marbles, limestones, travertines, rate.
Meanwhile, Fluorite sits at hardness 4 and can be scratched by a knife.
The answer is <span>A. versatility</span>
The answer is D. The natural selection is a theory which illustrates the gradual process of evolution in the population due to the change of environment. The key point is the mutation (variation) exists in the population before the environment changing. For C, if the environment does not change, though the adaptation is useful to environment, it will not be selected. Because the organisms without the adaptation will not die.
