Which of the following is not a biotic factor

The option that is not a biotic factor is "pressure." Biotic factors are living or once-living organisms in an ecosystem, including plants, animals, and microorganisms. These organisms interact with each other and with their physical environment to form complex ecosystems. Some examples of biotic factors include parasites, predators, and grazers, which are all organisms that live and interact with other organisms in the ecosystem. Pressure, on the other hand, is not a living organism and does not interact with other organisms in the ecosystem. Pressure can refer to a variety of physical forces, such as atmospheric pressure, water pressure, or pressure from gravity. While these forces can certainly affect the biotic factors in an ecosystem, they are not themselves living organisms and are therefore not considered biotic factors. In summary, biotic factors are living or once-living organisms in an ecosystem that interact with each other and with their physical environment. Parasites, predators, and grazers are all examples of biotic factors. Pressure, on the other hand, is not a living organism and is not considered a biotic factor.