Answer:
Explanation:
It is called a double circulatory system because blood passes through the heart twice per circuit. The right pump sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart. The left pump sends the newly oxygenated blood around the body.
Answer:
recessive
Explanation:
a recessive allele is the gene donated by one parent which is present within the genotype, but is not expressed in the phenotype of the person's characteristics.
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:
False
Explanation:
Almost all coal that is used today has its origins in the Carboniferous period. The Carboniferous period was a warm and wet one, with the majority of the land being swampy and covered with dense rainforests of ancient tree species. By the end of this period, the climate quickly changed, resulting int he collapse of the rainforests. As the trees were dying out, they were falling in the swamps, quickly being covered by the mud, so remaining largely preserved. Over time they got exposed to higher pressure and temperatures as they were getting deeper into the crust, eventually resulting in the formation of the coal.