Answer:
A.The hole in the ozone layer
Explanation:
• Montreal protocol is an international treaty that was signed to control the use of substances that are resulting in the depletion of the ozone hole.
This treaty was signed in the year 1987 and became effective form 1989.
• Since the time that this treaty has come into force, there has been a significant improvement in the ozone hole that was observed over Antarctic as it's size has decreased.
• This improvement has been possible because the treaty helped to phase out chemicals such as chlorofluorocarbons, carbon tetrachloride, etc. that are responsible for ozone hole depletion.
Answer:
The amount of people per square mile or kilometer of land; also called arithmetic density.
Answer: B. secrete enzymes that kill bacteria
Explanation:
Paneth cells, so-called because they were first described by Dr. Josef Paneth in 1888, are pyramidal cells, with the nucleus in the basal position, and with large granules in the apical position. Its first isolated specific product was the lysozyme, a bactericidal substance, by Alexander Flemming. These cells play an important role in innate immunity in the small intestine, producing a wide diversity of antimicrobial peptides and enzymes such as lysozyme itself, cryptidines, defensins and a lectin with bactericidal properties.
Answer:
Option (B).
Explanation:
Peyer's patches are the small masses of aggregated small lymphatic tissues and provide immunity to an organism. Peyer patches are discovered by the scientiest Johannan Cornard Peyer.
Peyer's patches are located in the ileum region of small intestine. These patches control the growth of harmful bacteria and regulates the growth of intestine bacteria. T
Thus, the correct answer is option (B).
