Free-living flat worms = carnivores or scavengers
Have digestive cavity, mouth, pharynx
Parasitic Flatworms: = Feed on blood, tissue fluids, or pieces of cells from within a host
Answer:
True
Explanation:
It can rapidly increase if the environment is good for them
The complete statement made by Stephen Hawking is: "though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival of the species."
If one looks at our history, there are some events that defy our capacity for logical thinking. One would think that, as we possess this capacity, we would be able to direct our decisions towards the survival of the human species.
However, in many cases greed and the desire for personal gain have taken precedence. One good example was the burning of the great library of Alexandria, one of the most significant libraries in the ancient world. This magnificent collection was lost during the siege of Alexandria, when Julius Caesar set on fire the ships in the harbor.
Another example is the atomic bomb, when science has been used to invent one of the most destructive weapons known to us. Atomic warfare is still a threat that may end all life on Earth.
Furthermore, the greed of some corporations has led to multiple ecological catastrophes that endanger not only other species but our own future as well. One example is the Bhopal gas leak in India, where in 1984, due to poor maintenance, the chemical plant released 30 metric tons of methyl isocyanite into the atmosphere.
Answer:
A longer amount of time.
Explanation:
Neptune is farther away from the Sun than Mercury, making his orbit around the Sun bigger and therefore longer.
Answer: Nitrogen-fixing Bacteria
Explanation:
In the Nitrogen cycle, nitrogen fixing bacteria are very important in ensuring that plants get nitrogen to enable them grow and as animals have to eat plants, these bacteria are essential for our survival as well.
Plants are unable to use atmospheric nitrogen but nitrogen-fixing bacteria are able to synthesize ammonia from atmospheric nitrogen. They can then convert this to Nitrites and Nitrates which are more useful to plants and animals by extension.
