Did alleles for drug resistance occur in bacterial populations that afflict humans, prior to the widespread use of antibiotics in medicine and agriculture?

Yes, drug resistance existed before, but it increased after the  widespread use of antibiotics

Explanation:

Drug resistances in bacteria  usually occurs as a consequence of mutation. Individuals that carry the resistance mutation survive even after the treatment with antibiotics. So, these mutations are advantageous for bacteria and thus, become favourable by natural selection (natural selection is evolutionary mechanism which favours traits of an organism that help him survive and reproduce). Resistant bacteria that survived after the use of antibiotics had the favuoruable trait (resistance) by natural selection.

Bacteria can even transfer drug-resistance to other bacteria via the process of conjugation, transducton or transformation.

humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of invasive species (such as new predators and food competitors), overhunting, and other influences. explosive, unsustainable human population growth is an essential cause of the extinction crisis.

explanation:

i didn't have the answer choices , but i tried my best.

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.