The correct answer is option (C) One student measures liquids for the experiment by holding the flask up at eye level. The other student measures liquids for the experiment while the flask sits on the table. Measuring liquids by holding the flask at eye level is the greatest amount of error in the experiment.
When liquid is being measured in a flask, the liquid shows a curve downwards which is called the meniscus. For measuring the transparent liquids, the lower meniscus touching the graduation of the should be considered and for measuring the colored liquids, the upper meniscus touching the graduation of the flask should be considered. When, the measurement is done by holding the flask at eye level there is always an error as it should be kept on a flat surface and measured by eyes directly leveling with the liquid. This gives a correct measurement which was done by the other student. Thus, one student measuring the liquid by holding the flask at eye level will have a wrong measurement and the other student measuring the liquid while the flask sits on the table gives the correct measurement and the results of the experiment will vary.
Answer:
The barrier functions to regulate the chemical composition of the extracellular fluid surrounding the brain cells.
Explanation:
Blood-brain barrier
It is a very selective semipermeable membrane , hence allow some specific substance to pass via it . This barrier separates the extracellular fluid in the central nervous system and the circulating blood from the brain .
<u>The barrier is composed of the endothelial cells .</u>
Passive diffusion is shown in this system , and allows molecules like the water , glucose , amino acid to pass .
It regulates the chemical composition of the fluid of brain cell .
Correct answer: B). The phagocytotic barrier, which is a part of innate immunity
The scenario represents the phagocytosis, which is a type of endocytosis by which the cell engulfs microbial pathogens. The main cells of the immune system that are involved in phagocytosis include macrophages, neutrophils, and dendric cells.
It is a mechanism which is used by the immune system to kill and processing of antigen that play an important role in innate immune response.
Hence, the correct answer would be option B.
I would think it would be C
