Question Discussion & Solution

Concept-

• A cell is defined as the smallest unit of an organism with a nucleus.
• cells are made from the same major classes of organic molecules: nucleic acids, proteins, carbohydrates, and lipids.

• Example- a unit in the tissue of an animal muscle.

Key PointsParts of cell-

Cell membrane

• It is also called the plasma membrane,
• It is found in all cells and separates the interior of the cell from the outside environment.
• It is the outermost wall in the animal cell and placed next to the cell wall in the plant cell.
• Being an outer boundary of a cell, it provides shape to the cell.

Cell wall

• A cell wall is defined as the non-living component, covering the outmost layer of a cell.
• cell wall separates the interior contents of the cell from the exterior environment.
• It also provides shape, support, and protection to the cell and its organelles.

Nucleus

• A nucleus is defined as a double-membraned eukaryotic cell organelle that contains genetic material.
• It contains the cell’s hereditary information and controls the cell’s growth and reproduction
• It is responsible for coordinating many of the important cellular activities such as protein synthesis, cell division, growth, and a host of other important functions.

Ribosomes

• The ribosome is a complex molecule made of ribosomal RNA molecules and proteins that form a factory for protein synthesis in cells.

Additional Information  Cell was discovered by Robert Hooke in 1665, the cell has a rich and interesting history that has ultimately given way to many of today's scientific advancements.

Here the pattern is,

8 + 1² = 8 + 1 = 9

9 + 2² = 9 + 4 = 13

13 + 3² = 13 + 9 = 22 ¹ 27

22 + 4² = 22 + 16 = 38

Hence, 27 is the odd one out

Important Points

• The Government of India was ready with repression during and even after the First World War.
• Throughout the war, repression of nationalists had continued.
• The revolutionaries had been hunted down, hanged, and imprisoned.
• Many other nationalists such as Abul Kalam Azad had also been kept behind bars.
• The Government then decided to arm itself with more far-reaching powers, which went against the accepted principles of rule of law, to be able to suppress those nationalists who would refuse to be satisfied with the official reforms.
• For this reason, in March 1919, the Government passed the Rowlatt Act even though every single Indian member of the Central Legislative Council opposed it.
• Three of them, Mohammed Ali Jinnah, Madan Mohan Malaviya and Mazhar-ul-Huq resigned from their membership of the Council.
• This Act authorized the Government to imprison any person without trial and conviction in a court of law.
• The Act would thus also enable the Government to suspend the right of Habeas Corpus which had been the foundation of civil liberties in Britain.

Additional Information

• Just six months before the Montford Reforms were to be put into effect, two bills were introduced in the Imperial Legislative Council.
• One of them was dropped, but the other, an extension to the Defence of India Regulations Act 1915 was passed in March 1919.
• It was what was officially called the Anarchical and Revolutionary Crimes Act, but popularly known as the Rowlatt Act.
• It was based on the recommendations made in the previous year to the Imperial Legislative Council by the Rowlatt Commission, headed by the British judge, Sir Sidney Rowlatt, to investigate the ‘seditious conspiracy’ of the Indian people. (The committee had recommended that activists should be deported or imprisoned without trial for two years and that even possession of seditious newspapers would be adequate evidence of guilt).
• The act allowed political activists to be tried without juries or even imprisoned without trial.
• It allowed the arrest of Indians without a warrant on the mere suspicion of ‘treason'.
• Such suspects could be tried in secrecy without recourse to legal help.
• A special cell consisting of three high court judges was to try such suspects and there was no court of appeal above that panel.
• This panel could even accept evidence not acceptable under the Indian Evidences Act.
• The law of habeas corpus, the basis of civil liberty, was sought to be suspended.
• The objective of the government was to replace the repressive provisions of the wartime Defence of India Act (1915) with a permanent law.
• So the wartime restrictions on freedom of speech and assembly were re-imposed in India.
• There was strict control over the press and the government was armed with a variety of powers to deal with anything the authorities chose to consider as terrorism or revolutionary tactics.

The correct answer is Mercury.

Key Points

• Mercury is the closest planet to the Sun.
• The planet probably received this name because it moves so quickly across space.
• Temperature variations on Mercury are the most extreme in the solar system ranging from 90 K to 700 K.
• Mercury is the second densest major body in the solar system, after Earth.

Important Points 

• The solar system is made up of the sun and everything that orbits around it, including planets, moons, asteroids, comets, and meteoroids.
  • It extends from the sun, called Sol by the ancient Romans, and goes past the four inner planets, through the Asteroid Belt to the four gas giants and on to the disk-shaped Kuiper Belt and far beyond to the teardrop-shaped heliopause.
  • Scientists estimate that the edge of the solar system is about 9 billion miles (15 billion kilometers) from the sun.
  • Beyond the heliopause lies the giant, spherical Oort Cloud, which is thought to surround the solar system.

Additional Information 

•  The sun is at the center of our solar system and is its largest object, accounting for 99.8% of the solar system's mass.
  • Our sun is a giant, raging ball of fire powered by nuclear reactions, and it provides the energy that sustains life on Earth.
  • The life-giving star is a yellow dwarf star made up of gas: about 91% hydrogen and 8.9% helium, according to NASA.
  • Compared with other stars, the size of the sun is relatively small and it's just one of the hundreds of billions of stars in our home galaxy, the Milky Way. 

The correct answer is Nitrification.

Key Points

• The process of conversion of ammonia into nitrate nitrogen is called nitrification.
• It is done in two steps- Nitrite formation, Nitrate formation.
• Nitrite formation- Ammonia are oxidized to nitrites by Nitrococcus, Nitrosomonas.

Additional Information

• The nitrogen cycle has four steps-
  • Nitrogen Fixation- Conversion of molecular nitrogen into the inorganic nitrogenous compound.
  • Ammonification- Conversion of the dead organic nitrogenous compound into ammonia.
  • Nitrification- Oxidation of ammonia into nitrates.
  • Denitrification- Nitrites or nitrates converts back into molecular nitrogen.