Answer: The study of plant varieties.
Explanation:
This question relates to the studies that Gregor Mendel, founder of modern genetics, performed at the University of Vienna.
Experimenting on pea plants, Gregor Mendel was able to establish a lot of the rules of heredity that we know today even though his research was not fully appreciated or understood during his own life.
He credited the study of plant varieties to have been most crucial to his final analysis because farmers had been crossbreeding varieties for millennia to bring about better traits in plants.
Answer:
<em>Cellular transport is the movement of ions or molecules across the membrane of the cell through either active or passive process.</em>
Explanation:
During active transport, ATP (Adenosine triphosphate) is used. In passive transport, ATP is not used. In active cellular transport, the ions move across the membrane against the concentration gradient.
For ATP to be used, it has to get hydrolyzed thereby forming ADP and inorganic phosphate. On the other hand, ADP captures the energy through the oxidation process taking place in the cell.
Answer:
1. Stabilizing Selection
2. Directional Selection
3. Disruptive Selection
Explanation:
Stabilizing Selection
This type of natural selection occurs when there are selective pressures working against two extremes of a trait and therefore the intermediate or “middle” trait is selected for. If we look at a distribution of traits in the population, it is noticeable that a standard distribution is followed:
Example: For a plant, the plants that are very tall are exposed to more wind and are at risk of being blown over. The plants that are very short fail to get enough sunlight to prosper. Therefore, the plants that are a middle height between the two get both enough sunlight and protection from the wind.
Directional Selection
This type of natural selection occurs when selective pressures are working in favour of one extreme of a trait. Therefore when looking at a distribution of traits in a population, a graph tends to lean more to one side:
Example: Giraffes with the longest necks are able to reach more leaves to each. Selective pressures will work in the advantage of the longer neck giraffes and therefore the distribution of the trait within the population will shift towards the longer neck trait.
Disruptive Selection
This type of natural selection occurs when selective pressures are working in favour of the two extremes and against the intermediate trait. This type of selection is not as common. When looking at a trait distribution, there are two higher peaks on both ends with a minimum in the middle as such:
Example: An area that has black, white and grey bunnies contains both black and white rocks. Both the traits for white and black will be favored by natural selection since they both prove useful for camouflage. The intermediate trait of grey does not prove as useful and therefore selective pressures act against the trait.
the atmospere would drift off into space
none needed
