Natural selection is the process by which individuals with characteristics that are advantageous for reproduction in a specific environment leave more offspring in the next generation, thereby increasing the proportion of their genes in the population gene pool over time. Natural selection is the principal mechanism of evolutionary change, and is the most important idea in all biology. Natural selection, the unifying concept of life, was first proposed by Charles Darwin, and represents his single greatest contribution to science.
Natural selection occurs in any reproducing population faced with a changing or variable environment. The environment includes not only physical factors such as climate or terrain, but also living factors such as predators, prey, and other members of a population.
Mechanism of Natural Selection
The mechanism of natural selection depends on several phenomena:
• Heredity: Offspring inherit their traits from their parents, in the form of genes.
• Heritable individual variation: Members of a population have slight differences among them, whether in height, eyesight acuity, beak shape, rate of egg production, or other traits that may affect survival and reproduction. If a trait has a genetic basis, it can be passed on to offspring.
• Overproduction of offspring: In any given generation, populations tend to create more progeny than can survive to reproductive age.
• Competition for resources: Because of excess population, individuals must compete for food, nesting sites, mates, or other resources that affect their ability to successfully reproduce.
Given all these factors, natural selection unavoidably occurs. Those members of a population that reproduce the most will, by definition, leave more offspring for the next generation. These offspring inherit their parents' traits, and are therefore also likely to succeed in competition for resources (assuming the environment continues to pose the same challenges as those faced by parents). Over several generations, the proportion of offspring in a population that are descended from the successful ancestor

Uloborid spider eggs and spiderlings. In any given generation, populations tend to create more offspring than can survive to reproductive age.
increases, and traits that made the ancestor successful therefore also increase in frequency. Natural selection leads to adaptation, in which an organism's traits conform to the environment's conditions for existence.
I so I am also a bit confused, but I hope this could answer your question!
Explanation:
The bacteria possess a cell wall composed of peptidoglycan molecule formed by the amino acids called murine. The bacterial cell wall helps in the survival of the bacteria in some extreme condition like when placed in a hypotonic solution.
The hypotonic solution is formed when it has low solute concentration and high water amount when compared. When the bacterial cell will be placed in hypotonic solution then the water will move inside the cell down the concentration gradient as a result of which the bacterial cell will swell but will not burst.
This happens as the cell wall contains expansin protein which allows the cell wall to expand and provides rigidity to the cell.
An inclined plane is a simple machine. An inclined plane is a ramp used to reduce the effort needed to raise or lower an object over a vertical height.
It is easier to climb stairs to get to a second floor than to climb straight up a rope. It is easier to walk up a long, gentle hill than to climb up a short, steep hill
, both condition work is done by gravity which is conservative force. So work is same. But if we will take friction force then for your kind information total world done on plane will be more than stairs due to longer path of plane were against of non conservative force.
The following are examples of inclined planes:
* Loading ramp
* Stairs or wheelchair ramp
* Mountain road
* Threaded screw.
The ancient Egyptians used inclined planes, or ramps, to move huge blocks of stone to build the pyramids.
