Answer:
Option D, Gastric Juices
Explanation:
The second line of defense is a non specific defense mechanism in which no specific individual is targeted but all invaders are killed in general way. Some common mode of second line of defense are - Phagocytic cells (white blood cells), inflammatory responses, macrophage system etc. The second line of defense comes into action when the invader has surpassed the first line of defense which include either physical barrier like skin, mucous membrane, hair, cilia etc. or chemical barriers like gastric juices, saliva, Hyaluronic acid etc.
Hence, gastric juice does not belong to second line of defense.
Thus, option D is correct.
Answer:
A considerable increase in phytoplankton populations in winter, and a greater increase in spring due to increase in light intensity.
Explanation:
Nitrogen and phosphorus are important nutrients required by phytoplankton populations. The growth of phytoplankton populations is dependent on the level of the availability of Nitrogen and Phosphorus in the presence of sunlight.
A rise in the aquatic coastal levels of nitrogen and phosphorus would result in a great increase in phytoplankton populations in spring, as stimulated by nutrient enrichment coupled with the availability of sunlight during spring. Phytoplankton populations would increase also in winter but not as high when compared to the rise in population in spring
The number of neutrons in each atom
