The answer is Gravity. To ensure the one-way flow of blood the veins contain a network of valves which arteries do not have. The reason is for the veins to counteract the force of gravity on flow of blood. For example, to increase the pressure of the blood back to the heart the veins must counteract the force of the gravity.
Answer: A) gravity
Explanation: I Took The Pre-Test On US Test Prep.
Answer:
True
Explanation:
The air, aka the atmosphere, is like a protective blanket around the Earth that keeps it warm amongst other things.
b. activity level
c. health status
d. genetic makeup
Answer:
Activity level.
Explanation:
Metabolism is the important for the cell survival and its growth. Most of the metabolic factors does not depend upon the control of the organism and occurs itself in the body.
Some factors can be improved or controlled by the activity level. The activity level can be controlled by the individual and may affect the flexibility and may also affect the other metabolic factor. One can control its own activity level.
Thus, the correct answer is option (b).
They share a common ancestor.
They compete for resources.
One organism evolved into the other organism.
Answer: The correct answer is -
They share a common ancestor.
Explanation:
Evidences for the common descent of living organisms (that is whether they have evolved from the same ancestor) have been elucidated through phylogenetic tree.
A clade (also called monophyletic group) is considered as a group of individual organisms, with common ancestor and its descendants. It indicates a single "branch" on the phylogenetic tree (also known as "tree of life).
Therefore, two organisms belonging to the same clade share common ancestor.
b.) The relationship is mutually beneficial.
c.) They share the same niche.
d.) One species benefits, while the other is neither helped nor harmed.
Answer:
C (they share the same niche)
Explanation:
Competition is a relationship between organisms resulting in a contest when both are trying to use the same resources related to their growth, reproduction and survivability. It is as a result of limited resources. Competition occurs in virtually all ecosystems in nature. This relationship develops when more than one organism in an environment has the same need for resources (niche) as another, to survive.
Each organism has a specific place in the ecosystem called NICHE. A species' niche is basically its ecological role or the function to which it is especially suited, which is defined by the set of conditions, resources and interactions it needs or can use.
The competitive exclusion principle says that two species can't coexist if they occupy exactly the same niche (competing for identical resources) or to put it in another way, two species in an ecosystem are bound to compete when they share the same niche (need for resources).
Answer:
The correct answer would be - Hydrangea plants depend on the concentration of some element which is affected by the acidic or basic nature of the soil.
Explanation:
Hydrangeas plants produce two different type of flowers blue and pink. The color of the plant depends on the pH of the soil or the acidic or basic nature of the soil. If the pH of the soil is acidic which means 5.5 or less the color of the flower would be blue and if it is near or above the 6.5 flowers would be pink.
So, it is clear that the concentration of any element that affected by the pH of the soil is responsible for the color of the flowers, in this case, it is found that the concentration of aluminum ions (Al+++) in the soil. When the soil is alkaline less concentration aluminum available for the plant and more available to the plant when the soil is acidic.
The color of hydrangea flowers is influenced by soil pH, with acidic soil producing blue flowers, and neutral to basic soil producing pink ones.
The information given about hydrangea plants and the color of their flowers is an example of how environmental factors can affect biological characteristics. Their flower color is determined by the soil pH. Acidic soil with a pH of 5.5 or less triggers the hydrangea plants to produce blue flowers, while soil with a neutral to basic pH of 6.5 and up causes the flowers to be pink.
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