Answer:
Antibiotic resistance can evolved in bacterial population in the following ways:
Explanation:
- In response to constant exposure to antibiotics some members of a bacterial population develop some beneficial mutations in some essential genes that gives them survival advantage in terms of food and space over the sensitive bacterial strains and hence they are capable of out-competing the sensitive bacteria.
- This happens due to the process of Natural Selection.
- These genes are called antibiotic resistance genes and bacteria usually carry them on plasmids in form of cassettes where genes resistant to multiple drugs are incorporated. These plasmids are called the MDR or Multi-Drug Resistance Plasmids.
- These resistant plasmids can be easily transferred among bacterial populations by conjugation, transformation or transduction or direct plasmid transfer.
- The resistant genes encode for proteins that render the drug ineffective by promoting their efflux from the cells, preventing their entry into the cell, chemically modifying them such that they become non-functional or altering the target site of the drug.
Answer:
D. In an ocean heated by volcanic activity
Explanation:
Most of Earth was covered in water, early organisms weren't evolved enough to walk on land at the time. There are some organisms that feed off of volcanic activity and use it as an energy resource and would adapt to the heat.
<em>"Hot spots create volcanoes on the seafloor. If these volcanoes rise above sea level to become islands, and if they occur in tropical waters, coral reefs will form on them. Since the volcanoes are cones, the reef forms in a circle around the volcano."</em>
<em>-</em><u>https://courses.lumenlearning.com/earthscience/chapter/ocean-organisms/</u>
<em>"Discovered only in 1977, hydrothermal vents are home to dozens of previously unknown species. Huge red-tipped tube worms, ghostly fish, strange shrimp with eyes on their backs and other unique species thrive in these extreme deep ocean ecosystems found near undersea volcanic chains."</em>
<em>-</em>https://ocean.si.edu/ocean-life/invertebrates/hydrothermal-vent-creatures
Human migration is the movement over long distances, movement from one country/region to another ) by people . Humans moved because of the c<span>hanging climate and landscape and inadequate food supply. </span>The first human movement was t<span>he movement of </span>Homo erectus<span> out of Africa across </span>Eurasia<span> about 1.75 million years ago. </span>
Than industrialization<span> encouraged migration wherever it appeared.
Wars also created migration. (</span><span>The First and Second World Wars, and wars, genocides, and crises sparked by them, lead to migrations).</span>
