When a particular mutagen identified by the Ames test is injected into mice, it causes the appearance of many tumors, showing that this substance is carcinogenic. When cells from these tumors are injected into other mice not exposed to the mutagen, almost all of the new mice develop tumors. However, when mice carrying mutagen-induced tumors are mated to unexposed mice, virtually all of the progeny are tumor free. Why can the tumor be transferred horizontally (by injecting cells) but not vertically (from one generation to the next)

because the mutagen induced tumor causing mutations in somatic cells, not in gamete producing cells in the germline.

Explanation:

The gene can be transferred either horizontally or by vertically.

The above scenario is related to horizontally transferred of mutagen by tumor cells to the non-exposed mutagen mice. By transfer of mutagen cells, tumor develop the mice. When mutagen-induced tumor mice are mated with unexposed mice, there will be no development of tumor into the progeny.

It clearly shows that mutation occurs in the somatic cells only due to mutagen and it does not affect the gamete producing cells in the germline.

starchy vegetables are high in carbohydrates.

starchy vegetables contain more carbohydrates than non-starchy vegetables.

explanation:

there are two primary categories of carbohydrates, essentially differentiated on the basis of their carbohydrate content (which is in the form of starch - a complex carbohydrate):

those vegetables which contain little amounts of starch are termed as non-starchy vegetables, and some examples include: artichokes, broccoli and bean sprouts.

vegetables high in their starch content are distinguished as starchy vegetables, and some examples include: potatoes, chickpeas and corn.

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: