Stimulus
A change in an organism's environment that causes it to react is called a stimulus. Stimuli can be physical, chemical, or biological factors that trigger a response in an organism to help it adapt and survive in its environment.
Certain chemicals and radiation in the environment can cause a reaction or mutation in an organism. Such changes may alter organisms genotype or phenotype. Chemicals that induce changes in organisms DNA is called mutagens.
stimulus
bacteria, and other infectious agents are called pathogens. This also includes viruses, even though they technically aren't organisms
Lichen that is your answer!! :))
a stimulus
Stimulus.
a pathogenic organism is an organism that is harmful to human cell rebuildingany organism which is causing any infection or disease causing alterations our immune system are called pathogenic organisms. the organisms like bacteria virus fungi can be termed as pathogens. the organism can be pathogenic by it self causing sever damage to the immune system or the metabolocal toxins released as byproduct.Path means disease. -gen means to make. It really helps to learn medical terminology. The word then means to make a disease. So a pathogenic organism is one that produces a disease.See link below:Pathogenesis is the creation of disease; when this genesis of disease is caused by [usually] microscopic organisms these microbes are said to be pathogenic.
both, but the environment influences the organism more. this causes the organism to change and they start to influence the environment a.k.a THEY ADAPT
A bacterial organism called clostridium botulinum
stimulus
A disease causing organism is called a pathogen.