Generally, when the altitude increases, what happens to the atmospheric pressure, temperature, and concentration of available oxygen?

With increasing height in the atmosphere, the atmospheric pressure declines and the concentration of the available oxygen decrease to a point that precludes aerobic respiration. Image from: https://kids.britannica.com/students/assembly/view/107829

Which of the following is not a way by which bioaerosols may form?

Microbes can become airborne by the eruption of rising bubbles through the sea-surface microlayer. If the wind speed is high enough, spume drops can be ejected from the breaking wave crest. The bubble-bursting results in an enrichment of microbes in the aerosol compared to subsurface water.

Image from: References

Fröhlich-Nowoisky, J., Kampf, C. J., Weber, B., Huffman, J. A., Pöhlker, C., Andreae, M. O., … Pöschl, U. (2016). Bioaerosols in the Earth system: Climate, health, and ecosystem interactions. Atmospheric Research, 182, 346–376. doi:10.1016/j.atmosres.2016.07.018

Which of the following is not a reason why spores are better adapted in the atmosphere?

Bacterial spores are the most dormant form of bacteria since they exhibit minimal metabolism and respiration, as well as reduced enzyme production. Endospores are resistant to the chemical agents, e.g., triphenylmethane dyes, and can even protect the bacterial cells against ultraviolet radiation, extreme pH gradients, drought, and nutrition depletion. Image from: https://biologyease.com/endospore/

Which of the following is not a passive mechanism that discharge spores into the atmosphere?

The gleba is a solid mass of spores, generated within an enclosed area within the sporocarp. When a critical pressure is reached inside the cells of the elastic membrane, the membrane everts rapidly, discharging the gleba from the cup.

Which of the following is not a property of the environment that affects the dispersion of air spore in air currents?

Which of the following can be observed by looking at the ratio of the number of microorganisms in the rhizosphere soil (R) to the number of corresponding microorganisms in soil remote from the roots (S) (R/S ratio)?

Rhizosphere effect is measured on quantitative basis using the R:S ratio number of microorganisms in the rhizosphere (R) is increased relative to the number in the bulk soil (S). Image from: https://www.researchgate.net/publication/308915540_The_Role_of_Root_Taper_on_Soil_Erodibility_A_Critique_on_the_Tripartite_Classification_of_Rooted_Soils