Answer: B. Melting temperatures of primer should be between 55-80 degree Celsius.
Explanation:
Bacause the melting temperature controls the binding of the primers to your template DNA. At melting temperature 50% of the primer molecules are bound to their corresponding target sequence. If the difference in melting temperature between the two primers is too high, it might be difficult to find experimental conditions where both primers can bind to their target.
The answer is descent with modification.
Descent with modification practically means that a species have changed appearance wise over long periods of time to adapt to their environments better.
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.
Answer:
C. It is active transport, and moves against the concentration gradient.
Explanation: Pinocytosis is an active transport in which the molecules move from a low to a more higher concentration gradient. During this process it requires energy to move molecules and the energy used is ATP.
Their fur color is very similar to the color of the bark on the eucalyptus tree.
