The heart/lung machine is necessary
when performing heart transplant surgery because during surgery, the actual
heart is stopped so the heart/lung machine acts as a substitute heart that supplies
oxygen and pumps blood to the body until the actual heart start functioning.
Answer: A, through extensive testing and the accumulation of several lines of evidence
Explanation:
1. Scientific method is the techniques that scientists used to carry out investigation process. It is made up of five steps, which are:
a. Observation: this is the stage in which a scientist make an observation to which he did not have an explanation.
b. Formation of a research question: in accordance to observation made, the scientist form a question on which his experiment will be based
c. Formation of hypothesis: at this stage the scientist offers a proposed explanation for the observation which he had made and state what he expects at the end of the experiment.
d. Conduction of the experiment: at this stage the scientist carry out the experiment using appropriate means.
e. Analysis of data and drawing of conclusion: this is last stage of the investigation, at this stage, the scientist analysis the results he obtained and draw a conclusion based on the results of the data.
2. Scientists used scientific method to carry out scientific investigations because the method minimize the influence of bias and prejudice in the experiments that they carry out. The method provides an objective, standardized approach to scientific investigation; this result in reproducible results which can be achieved by other scientists in every parts of the world. The method also helps to minimize errors during investigation.
in our lungs
and throughout our blood stream
D. the <span>stomata close to preserve water and gas exchange decreases.</span>
