Some mutations have a positive effect on the organism in which they occur. They are called beneficial mutations. ... They increase an organism's changes of surviving or reproducing, so they are likely to become more common over time. There are several well-known examples of beneficial mutations.
The factor that would least affect photosynthesis is Nitrates in the soil.
Photosynthesis is the process by which plant make their own food by utilizing energy from sunlight, water and carbon dioxide. The limiting factors that affect photosynthesis are the light intensity, carbon dioxide concentration, temperature and water. Without enough light, a plant cannot photosynthesize very quickly, even if there is plenty of water and carbon dioxide.
The effect of such toxic chemicals to the body is that they stimulate uncontrolled cell division. Uncontrolled cell division or cells proliferation may lead to cancer. The unchecked cell growth results to mutations in genes that can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death.
