Which of the following is true concerning cancer cells?

a. They evade the normal controls that trigger programmed cell death.
b. They must be attached to a substrate to divide in culture.
c. They exhibit density-dependent inhibition when growing in culture.
d. They stop dividing in culture when growth factors are depleted.

a.They evade the normal controls that trigger programmed cell death.

Explanation:

Cancer cells are cells in the body that grow abnormal and uncontrollably. Continuous growth cancer cells results in the development of tumor as well as the ability to invade neighboring tissues.

Unlike normal cells that are controlled (reproduce only when needed) and are more specialized with specific functions, cancer cells are less specialized compared to normal cells and grow abnormally and rapidly. Cancers cells grow out of control, as they evade the normal control and ignore signals that activate apoptosis or programmed cell death which is used by the body system to destroy unwanted cells.

explanation:

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion