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.
Roots and leaves
The major driving force of water uptake in a large tree is transpiration.Transpiration is the process by which plants absorb water through the roots and release it as water vapor through the pores in their leaves. Once this water evaporates, a negative water vapor pressure is created or develops in the surrounding cells of the leaf. when this happens, water is pulled into the leaf from the vascular system, the xylem, to replace the water that has been transpired from the leaf.This pulling of water, or tension, that occurs in the leaf, will extend through the rest of the xylem column of the tree right into the xylem of the roots as result of the cohesive force holding the water molecules along the sides of the xylem tubing.The xylem is a continuous water column extending from the roots to the leaves.<span>Finally, the negative water pressure that occurs even to the roots will result in an increase of water uptake from the soil.</span>
Most cells in the body are diploids, germ line diploid cells will undergo meiosis to produce gametes. Fertilization following, the gametophyte phase is haploid and the part of the life cycle in which gametes are produced by mitosis of haploid cells.
Hope this helps!!!!
So what would happen if photosynthesis suddenly stopped happening? If photosynthesis came to an abrupt end, most plants would die within short order. ... That's because for photosynthesis to cease to exist, Earth would have to plunge into darkness.
