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: B
Explanation: During cell division, chromatin condenses to form chromosomes.
Answer:
Option B, Mammals and reptiles in the post-dinosaur age.
Explanation:
Adaptive radiation is mechanism through which species evolve very fast from common single ancestors. In simple words two different species are said to have evolved through adaptive radiation when they have descended from a single lineage. This is not the case with mammals and reptiles.
Generally in adaptive radiation, a species evolve when it faces new environmental challenges due to change of habitat or area. For example mammals have evolved from dinosaurs.
Hence, option B is correct
Answer: The virus weakens as time passes.
Explanation: The virus will weaken continuously during transmission, and will reduce its toxicity after several generations of transmission, without causing much harm to the human body.