Answer:
option d is correct. the existence of land bridges between continents.
Explanation:
landland bridge theory which was used to explain why species would end up continents over, such as mammoth travelling to North America, thisthis theory was based on the idea that water eventually Rose to cover these bridges rather than the at having individual plates that moved away from each other.
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: 3. in the icecaps. 2. temperature. 1. the second one
Explanation:
The rough endoplasmic reticulum (versus the smooth), which is where the ribosomes are and make proteins.
