All the genetic mutations may occur spontaneously in organisms is t he incidence of such mutations may be increased by what?

Both physical and chemical factors

Explanation:

A mutation is any alteration in the DNA sequence of the genome of a particular cell/organism. Depending on the type and localization, a mutation can be neutral, deleterious, or even beneficial for the individual that possesses it. Moreover, the mutation rate refers to the probability for a mutation to appear in a cell/organism. Exposure to physical environmental factors (e.g. ultraviolet radiation, X-rays, gamma rays, etc) and chemical factors (e.g., bromine) can increase this likelihood.

physical and chemical factors

Explanation:

Factors that alter the critical chemical and physical characteristics of ecological systems include temperature, pH electrochemical (redox) potential, and the transparency of air and water.

1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.