Answer;
-Analytical chemistry - composition.
Environmental - impact of chemicals
Explanation;
-Analytical chemistry involves the qualitative and quantitative determination of the chemical components of substances. In qualitative analysis all the atoms and molecules present are identified, with particular attention to trace elements. In quantitative analysis the exact weight of each constituent is obtained as well.
Environmental chemistry is the study of the chemical and biochemical phenomena that occur in the environment.It relies heavily on analytical chemistry and includes atmospheric, aquatic, and soil chemistry.
<span>photosynthesis in algae cells </span>
Answer: Option B
Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical barriers that are always ready to protect the body from infection.
Example: Skin and mucous membrane.
Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.
Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.
So, skin and mucous membrane are the first line of defense.
