Answer:b)lubricating surfaces
Explanation:took it on edge hope this helped
Answer: d) lightheadedness or unconscious episodes.
Explanation:
There are several ways the body responds to stress but one method used by psychologists to measure this response is Hans Selye's general adaptation syndrome. This occurs in 3 stages:
1. The alarm reaction. This occurs when the stressor is first presented resulting in the RELEASE OF HORMONES from the adrenal gland into the blood stream. The hormone in turn cause sympathetic nervous system activation and increase energy levels, INCREASE RESPIRATION, increase muscle tension, reduce sensitivity to pain, slow down the digestive system, and cause a RISE IN BLOOD PRESSURE.
2. The stage of resistance- this occurs till the stress is removed.
3. The stage of exhaustion
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: B - A battery with wires
Explanation: The mitochondria is the cells source of energy
The population will later, cease to exist.
Since the population is experiencing (about) the same rates of immigration and emigration, these 2 factors will not change anything.
A low birth rate and a high death rate means that more people are dying than being born.
Therefore the population will decrease until there is nobody and it will cease to exist.
