The owl is a generalists creature/species because it is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either group, however. Some species are highly specialized (the most extreme case being monophagy), others less so, while some can tolerate many different environments. In other words, there is a continuum from highly specialized to broadly generalist species.
I believe a pot of water that is being heated by a electric burner. This is because the warmer water moves to the top and the cooler water moves down to the bottom of the pot. This causes a circular motion. The next example of convection heat is a hot air ballon rising and falling in the atmosphere. A radiator is also because the hot air is drawn out the top and the cooler air is drawn to the bottom.
Answer:
A) & B)
Explanation:
A) There are certain viruses that are present in both healthy and disease people.
Example: Polio virus is found in many human but it causes disesease in only 1% of human.
B) Viruses require host machinery for replication so they may not replicate in pure culture.
The postulate C is also violated, the virus may not produce disease in non-human experimental host because of inappropriate animal or vaccinated animal etc. Others exception includes, the same disease may be caused by various organisms and different organisms can also cause the same disease.