Question Discussion & Solution

The correct answer is Methane.

Key Points

• Methane (CH4)
  • It is the simplest hydrocarbon consisting of one carbon atom and four hydrogen atoms and the simplest hydrocarbon, is the most abundant hydrocarbon pollutant.
  • It is a powerful greenhouse gas.
  • Major natural sources of methane include emissions from wetlands, and oceans and from the digestive processes of termites.
  • Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere.

Additional Information

• Butane is a gaseous component (at room temperature and atmospheric pressure) of the Alkane group having the chemical formula is C4H10.
• It is a colourless, highly flammable, and easily liquefied gas.
• In the abundance of oxygen, it forms Carbon dioxide, but if limited oxygen is available, then it forms Carbon Monoxide.

2C4H10 + 13O2 → 8CO2 + 10H2O                   (oxygen in plenty)

2C4H10 + 9O2 → 8CO + 10H2O                      (oxygen is limited)

• Uses –
  • Gasoline blending
  • Fuel gas
  • Fragrance extraction solvent
  • Feedstock for the manufacture of ethylene and butadiene
  • Ingredient for synthetic rubber
  • Isobutane to enhance the Octane number of gasoline in refineries.
• A propane molecule has three carbon atoms and eight hydrogen bonds and has the formula C3H8. 
• Propane is a colourless, easily liquefied, gaseous hydrocarbon (compound of carbon and hydrogen) and the third member of the paraffin series following methane and ethane.
• Propane is produced as a by-product of two other processes, natural gas processing and petroleum refining.
• It is separated in large quantities from natural gas, light crude oil, and oil-refinery gases and is commercially available as liquefied propane or as a major constituent of liquefied petroleum gas (LPG).
• Uses: 
  • It is used in LPG, also used as biofuel in buses and taxis and it is also the main gas in blowtorches and for hot air balloons.
  • Propane gas has become a popular choice for barbecues and portable stoves because its low boiling point makes it vaporize as soon as it is released from its pressurized container.
• The chemical formula of Ethane is C2H6.
• It is a colourless, odourless gas at normal temperature and pressure.
• It is extracted from natural gas on an industrial scale and is a petrochemical by-product of petroleum refining.
• Michael Faraday first synthesized it in 1834, using the electrolysis of a solution of potassium acetate.

Y → Position value of Y is 25 which square of 5.

P → Position value of P is 16 which square of 4

I → Position value of I is 9 which square of 3

D → Position value of D is 4 which square of 2

Therefore, square of 1 is 1 and that corresponds to A.

Concept-

Vestigial organs are the organs that once were useful in an animal's body millions of years ago, but now they are useless or very close to useless.

Key Points Human heart-

• The human heart is not vestigial as at present times it has its own functions in the human body.
• The human heart is an organ that pumps blood throughout the body.
• Heart pumps the blood through the vessels of the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes.
• The tissues of the body need a constant supply of nutrition in order to be active which is performed by blood.

Additional Information Wisdom teeth

• Wisdom teeth are no longer totally necessary. Today, humans cook food to soften it, and we can cut and crush it with utensils.So at this time they are vestigial.
• Early humans needed to chew coarse, hearty foods, they required a broader jaw.
• Wisdom teeth grew in to give them more chewing power for this purpose.

Nictitating membrane of eye

• In humans, the nictitating membrane is the pink lump in the inner corner of the eyes which is known as the caruncula lacrimalis.
• In this structure, the remaining of the nictitating membrane are permanently folded into that corner and no longer functional.So it is vestigial.

Vermiform appendix

• The human appendix may be considered as a vestigial organ as it has been proved that the removal of the organ after infancy does not create any harm.
• Its function is to digest cellulose.

Pen is necessary for the writer to write their thoughts on paper.

The correct answer is Mode of Nutrition.

• In 1969, R.H. Whittaker introduced the five-kingdom system of classification.
• In the five-kingdom system, the basis of classification is the complexity of cell structure, physical organization, nutrition method, and life cycle.
• Aristotle firstly divided the living world into two groups, namely, flora and fauna.
• After that, in his book 'Systema Naturae', Linnaeus classified all animals into plants and animals.
• Linnaeus is called the 'father of modern classification system'.

Additional Information

• Whittaker classified all creatures in the following five kingdoms -

1. Kingdom Monera-
   • ​​This world consists of prokaryotic organisms ie Bacteria, Cyanobacteria, and Archaebacteria.
2. Kingdom Protista-

• This world consists of unicellular eukaryotic organisms. Yuglina, which is situated between plants and animals, is included in this world.

3. Kingdom Fungi-

• This includes organisms dependent on parasites and dead food for food. Their cell wall is made of chitin.

4. Plant World (Kingdom Plantae)-

• This world consists of algae and multicellular green plants.

5. Kingdom Animal-

• This includes all multicellular animals. It is also called 'Metazoa'.