The ames test is used to identify potential carcinogens. a compound tested resulted in a few scattered colonies growing on the media, similar to the control plate with no disk. what does this result imply? a. the compound in the disk is so toxic that it inhibits almost all growth on the plate. b. the few colonies that grew are resistant to the compound. c. the few colonies that grew contain reversion mutations that allow them to grow on media without histidine. d. the compound in the disk is not mutagenic so there was no increase in the reversion rate.

The correct answer is option D.

Explanation:

In the given case, a similar amount of colonies is witnessed in both control as well as the test plate. This concludes that it does not influence the organism, thus, there was no enhancement in the rate of reversion, that is, the number of colonies in the test plate does not get decrease. Thus, the compound in the disc is not mutagenic as there was no increase in the reversion rate.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave