Polymers are defined as large molecules assembled from smaller, individual molecules.
Answer: B)
Water has special characteristics because liquid water is denser than ice and ice floats on top of liquid water.
Answer: Option A & D
<u>Explanation:</u>
A water molecule is formed by the covalent bonding between two atoms of Hydrogen atom with one atom of Oxygen. In water, the Hydrogen bonds are the one that keeps the water molecule intact.
When the water molecule freezes the bonding becomes weak as they are separated and set apart which makes the liquid water denser than ice. Normally a substance floats if it is less dense. Ice floats because it is less dense than water.
With the advent of industrialization, several trees have been cut at an alarming rate for raw materials and various other purposes. This felling of trees can be regulated by selective cutting, clear-cutting and shelterwood cutting.
Forest fires are one of the common causes of loss of forests. Sometimes the forest land is set on fire to make the land available for commercial purposes. Once cleared, there can be no vegetation. Natural forest fires are also responsible for the destruction of huge forest covers. Latest fire fighting techniques should be adopted to conserve the forest. However, forest fires are an important part of the ecosystem and it helps replenish nutrients in the soil from dead and decaying matter.
More trees should be planted to increase the forest cover. Trees should be selected according to the geographical conditions of a particular region and proper care should be taken during the growth of trees.
Prevention of exploitation of forestry and forest products is necessary for the conservation of forest.
The existing forests should be protected from diseases by spraying chemicals, antibiotics or development of pest-resistant strains of trees.
Answer:
Other species that rely on those fish would die off. The extinction of one species can lead to the extinction of another and so on.
