Answer:
veins
Explanation:
Arteries carry blood away from the heart and veins carry blood back to the heart.
The fossils from prehistoric organisms can be compared to present day organisms showing the differences in how much thwy have changed.
Answer:
Approximately eight minutes.
The missing part of the question is as follows:
Phrase indicates a limit to the scientific accuracy of the experiment?
Answer:
The correct answer is - a sample size of 300 people.
Explanation:
In the given research Marcus developed a drug that is already 200,000 people taking the drug, and the scientist takes sample size of only 300 people for the experiment.
The sample is very small as compared to the total population who participated in the research. A sample size of 300 people is very small compared to 200,000 people. Such a small sample size will not give the proper idea and any effective result, there would be chances to miss some aspect or effect of the drug to be missed, so, this can be the limiting factor to the experiment.
Answer: Calcium carbonate shells of marine organisms, like coral, oysters, and clams.
Explanation:
Carbon dioxide in the gaseous form is absorbed from the atmosphere into the oceanic waters. The carbon dioxide is generated due to human activity like burning of fossil fuels, deforestation, and by other activities. This increases the acidity of the oceanic waters, it affects the reef building in animals. The animals use the carbon dioxide to produce calcium carbonate structures that are used for building up the coral reefs and exoskeleton like shells of oysters and clams. This way carbon dioxide become an important component in the structure of the living organisms in the ocean. This way carbon dioxide get stored in the structures of marine organisms being the largest reservoir of carbon dioxide.
