What is the lesson? It doesn't say.
Answer:
<em>The correct option is B) A rat scurries past, and a python strikes at it.</em>
Explanation:
A stimulus can be described as any thing or event which is detected as a signal and a response is generated by the body of the organism for that signal. In the scenario discussed in option B)The passing of the rat acts as a signal for the python. In response to the signal, the python generates a response by striking the rat. Hence, it is an example of a stimulus and the accompanying response of an organism.
Answer:
Differentiated cells have retained all their genetic potential
Explanation:
Differentiated cells are important in a multicellular organism because they are able to perform a specialised function in the body. Multicellular organisms must therefore retain some unspecialised cells that can replenish cells when needed. These unspecialised cells are called stem cells.
Antibiotics are meant to kill living things (bacteria). Viruses, on the other hand, we are not sure if they would classify as living. Viruses change the meaning of "life" if we consider them alive. They can <em>only </em>reproduce within another cell by taking over that cell. An antibiotic would have to be able to kill human cells to kill a virus, and that would not be a good medicine to take. Viruses invade a host cell and incorporate the virus DNA into the host cell's DNA, which would cause the host cell to create more viruses to invade other cells. <span />