Starlings are birds that were brought into the united states from europe for breeding purposes. their numbers have increased to such an extent that they have dislodged native birds, caused crop damage. they also carry swine diseases. what role do they play in the ecosystems of the united states?
a. dominant species
b. keystone species
c. invasive species

The correct answer is invasive species.

Explanation:

A species when introduced to a new region, in the presence of favorable environmental conditions they eventually grow in numbers through reproduction. In some cases the increase in the population size interferes with the existing flora(plants) and fauna(animals) and cause irreversible damage to the environment and human inhabitants too. In the current case, Starling birds are not native to United States however, they grew in numbers creating a tough competition for the native birds for the food sources and also posed a threat to humans as they are swine-disease agent carriers and hence they are termed as invasive species.

answers are:

lysogenic     viral dna merges with host cell dna

lysogenic     no symptoms

lytic               viral dna takes over

lysogenic     virus does not destroy host cell

lytic               virus destroys host cell

lytic               induces symptoms of viral infection

lysogenic       cell reproduces and spreads provirus