<span>The correct answer here is A. In a scientific experiment, the dependent variable is the variable that is being tested and then measured. The answer referenced in D, the variable that is manipulated, is referring to the independent variable.</span>
Answer:
gene flow
Explanation:
Gene flow, in simple terms, is a transfer of gene from one population to another. Also called as migration, where there is movement of individuals, and the genetic material they carry from one population to another. It also involves successful breeding of these individuals in their new locations. When people with sickle cell anemia were brought into the US, transfer of the gene responsible for sickle cell disease changed the frequency of the sickle cell allele in overall US population.
Answer:
The steps that can be seen in this story are observation and the questioning phase, which can also be called elaboration of the problem.
Explanation:
The scientific method is a set of phases that are able to guide researchers to the creation of scientific knowledge, through an experiment. This method is essential for conducting scientific research, allowing an experiment to be managed in a way that promotes answers to scientists' questions. The scientific method presents the phases called observation, questioning (or elaboration of the problem), elaboration of hypotheses, experimentation, analysis of the results and conclusion.
In the story shown in the question above, we can see the phases called observation and questioning. The observation takes place the moment Fleming noticed a fungus capable of growing on colonies of bacteria that cause throat infections, killing them. This observation made him enter the questioning phase, when he wondered if the fungus was able to prevent the growth of these bacteria.
Answer:
Parasympathetic nervous system
Explanation:
Parasympathetic nervous system (PNS) along with sympathetic nervous system (SNS) makes autonomic nervous system (ANS). ANS controls the functioning of internal processes like digestion rate, heart rate, respiratory rate etc. During a threat or stressful situation SNS is activated. It increases heart rate, respiratory rate and directs blood flow towards peripheral muscles as a part of "fight or flight response". When the situation becomes normal, PNS is activated which restores all the vitals as a part of "rest and digest" mechanism.
Since here Byron almost got into an accident, he was scared a lot due to which his SNS was activated. Eventually when he realized that he is out of danger, his PNS got activated which returned his heart rate and blood pressure to normal levels.
Enzymes are biological catalysts.They lower the activation energy necessary for the reaction to occur, and that makes the chemical reactions quicker in living cells.
