Paper production is basically a two-step process in which a fibrous raw material is first converted into pulp, and then the pulp is converted into paper. The harvestedwood is first processed so that the fibres are separated from the unusable fraction of the wood, the lignin. Pulp making can be done mechanically or chemically. In the chemical pulping process, alkali (e.g., sodium hydroxide in the form of a lye or caustic soda) is usually used to remove the lignin that binds the fibres. So, for degumming of raw material, caustic soda is used.

Allotropy is the property of some chemical elements to exist in two or more different forms, or allotropes, when found in nature. There are several allotropes of carbon like diamond, graphite, graphene, fullerene, etc.Coal is not an allotrope of carbon because it is not 100% carbon. It contains lot of silica, sulphur and other compounds of carbon apart from carbon.

In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis.Apogamy is a type of reproduction, occurring in some ferns, in which the sporophytedevelops from the gametophyte without fusion of gametes.Adventitious embryony also called sporophytic budding, is a type of apomixis in which an embryo develops directly from nucellus or integument tissue.So, all three are correct.

Carbon monoxide (CO) is very dangerous because it binds with the haemoglobin more efficiently than oxygen does. It "hogs the seats" so that oxygen can't get a ride. And those CO molecules keep riding around, never giving their seats up to the oxygen. This means there is no way to get oxygen to the brain, heart, or other cells and those cells start to die. And finally, it leads to suffocation and even death of a person.

The    HIV    virus    continuously    invades    and destroys  T-cells  (lymphocytes).  Eventually  the body can't replace the T-cells fast enough, and the  immune  system  deteriorates.  When  the immune  system has deteriorated to the point that it is unable to fight off diseases, a person is diagnosed with AIDS.