Answer:
A
Explanation:
Soil becomes less fertile the deeper it goes because the percentage of organic matter, such as humus and living organisms, decreases with depth. This reduction results in a lower nutrient content in the soil, lessening its fertility.
The soil gets less fertile the deeper it goes due to the increased distance from organic matter. The organic material of soil, called humus, is primarily found in the upper levels of the soil. It improves the soil structure and provides water and minerals to plants. As we go deeper into the soil, the quantity of this organic matter decreases which results in the soil being less fertile. The inorganic matter which primarily forms the deeper soil layers contributes less to fertility as it mainly consists of rock and lesser nutrients.
Besides, soil has different layers called horizons, each with distinct physical and chemical properties. These horizons include the A horizon which is a mixture of organic and inorganic products of weathering, and B horizon where there is an accumulation of mostly fine materials that have moved downward. The fertility of soil decreases as we move from the A horizon to the B horizon and further down.
Biological factors also play a significant role in the fertility of soil. The presence of living organisms greatly affects soil formation and structure. However, the number and impact of these organisms decrease with soil depth, also decreasing fertility.
#SPJ3
b. epiglottis
c. bronchiole
d. laryngopharynx
Answer:
The correct answer is option c. "bronchiole".
Explanation:
The passage of airway within the lungs is known as bronchus. However, air exchange does not happen in the bronchus, it happens in small air sacs named alveoli. The smaller versions of the bronchus are known as the bronchiole, which branches further until it becomes the alveoli, the structure at which air exchange takes place.
Answer: False
Explanation:
Humoral immunity depends on B Cells whereas cell immunity depends on T Cells.
T cells are not programmed to provide humoral immunity, which is primarily mediated by B cells. T cells are involved in cell-mediated immunity where they directly attack and destroy infected cells.
T cells are not programmed to provide humoral immunity. Humoral immunity, also known as antibody-mediated immunity, is primarily mediated by B cells which produce antibodies specific to each pathogen. T cells, on the other hand, are involved in cell-mediated immunity where they directly attack and destroy infected cells. Memory cells are a type of B and T cells that form after exposure to a pathogen and mount rapid responses upon subsequent exposures.
#SPJ11
b. to keep animals in zoos for people to see
c. protect species from extinction
d. stop hunting
Answer:
c
Explanation:
CFCs
DDT