Answer:
True
Explanation:
The stratosphere is the layer of the earth’s atmosphere which is above the troposphere and below the mesosphere.
The stratosphere contains about 90 percent of the ozone layer. The stratosphere is made up of ozone layers which helps in the absorption of about 95 percent of the ultraviolet rays from the sun and converting to heat.
This is the reason why depletion of the ozone layer found in the stratosphere gives rise to global warming.
Explanation:
New cells are created from a process called cell division. The new cells are produced when a cell, called the mother cell, divides into new cells called daughter cells. When two daughter cells have the same number of chromosomes as the original cell, the process is called mitosis
If another predator, that is more efficient hunter, enters the territory of the puffins, the puffins will find themselves in a very tough situation. They will either have to adapt very quickly, or die out.
The evolutionary pressure will be there fro the puffins to push them in a direction to adapt and be netter hunters, thus fight for their existence. That would mean that the puffin's beak, but also their speed and efficiency will have to improve in order to compete or even out-compete the new predator.
If the puffins do not manage to adapt relatively quickly, and a food shortage occurs, than they will die out, as they will lose the fight for food constantly.
The answer is; B
Mutation is one source of variation (in addition to sex and gene flow). Mutations are rare and occur in a small proportion of individuals. However, due to the advantage that the genetic mutation confers to these individuals, their chances of passing the genes to the next generation is higher than that of the general population.
This way, the allelic frequencies of these advantageous mutated genes increase with each generation and eventually become the majority population over time.