The answer is B. alcohol crosses the barrier that the placenta creates
The placenta usually consist of several layers of cells that act as a barrier for the diffusion of substance that connect the maternal and fetal circulatory system that very important for the fetus' growth. But sadly, it can't block Chemical really well and alcohol can screw it u
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.
Answer – C (Using instruments that have not been calibrated).
When the integrity of an instrument’s calibration has been compromised (usually due to exposure to a shock, vibration, or physical damage), it needs to be calibrated; failure to do this inevitably leads to inaccurate measurement; this is a very common measurement error.
Sickle cell disease has a benefit in malaria infection because it makes the parasites easier to eliminate. This makes a person with sickle cell disease is more likely to survive the malaria infection, which found many in Africa.
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Sickle cell disease has a few drawbacks because it makes the red blood cells less durable, which lead to the destruction of more red blood cells. In normal condition(where malaria doesn't exist like in America), this gene will make the organism less likely to survive than those who don't have the gene.</span>