Answer:
D
DNA, cytoplasm and cell membranes
Fertile soil is valuable because there is a limited supply. Less than one eighth of land on Earth has soil that are well suited for farming.
The thick, fertile soil of the prairies took many thousands of years to develop.
The two ways that the value of soil can be reduced is help use soil correctly, peanuts were once a corp to help soil, and still can be. The soil value recycle rocks and bedrock.
The value of soil is reduced when it loses its fertility and when topsoil is lost due to erosion. Soil can be conserved through contour plowing, conservation plowing and crop rotation. The thick mass of tough roots at the surface of the soil.
When it is said that mutation is the ultimate source of genetic variation it means that it creates several new combinations which is similar to meiosis and fertilization because <span> new alleles and genes appear. It is just about some common points.</span>
A cell can only respond to signals from other cells, not from the physical environment. receptor activation. The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on: the presence of the appropriate receptors on the cells of the target tissue or organ.