Question Discussion & Solution

CONCEPT:

• Newton's first law states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by any external force.
• Newton's Second Law of motion states that the rate of change of momentum of an object is proportional to the applied force in the direction of the force i.e.,

​ \(F = \frac{{dp}}{{dt}}\)

Where F = force applied, m = mass of the body, and a = acceleration produced.

• Newton's Third Law of Motion states that 'To every action, there is an equal and opposite reaction'.

EXPLANATION:

• The launching of a rocket illustrates Newton’s third law of motion. Therefore the option 1 is correct.
• Newton's Third Law of Motion states that 'To every action, there is an equal and opposite reaction'.
• So, when the rocket is ignited, it releases gases from its thrusters thereby creating a force that will push rocket upwards and it can gain extreme velocity using this principle.

• Newton's third law of motion is applicable irrespective of the nature of the forces. The forces of action and reactions may be mechanical, gravitational, electric, or of any other nature.
• Action and reaction always act on different bodies. If they acted on the same body, the resultant force would be zero and there could never be accelerated motion.
• The forces of action and reaction cannot cancel each other. This is because action and reaction, though equal and opposite, always act on different bodies and so cannot balance each other.
• No action can occur in the absence of a reaction. 

1. Three friends, Vinitha, Mira and Neethu, had lunch at a hotel.

2. When the bill was received, Vinitha paid 2/3 as much as Mira paid and Mira paid 1/2 as much as Neethu paid.

Vinitha = Mira       ---(i)

Mira =  Neethu

2 Mira = Neethu       ---(ii)

As, the total bill was divided among them

So, Vinitha + Mira + Neethu = 1       ---(iii)

Substituting the value of (i) and (ii) in (iii), we get:

Mira + Mira + 2 Mira = 1

Mira = 3/11

• A mistake is essentially any programmer action that later shows up as an incorrect result during program execution
• A programmer may commit a mistake in almost any development activity; For example, during coding a programmer might commit the mistake of not initializing a certain variable or might overlook the errors that might arise in some exceptional situations such as division by zero in an arithmetic operation, both these mistakes can lead to an incorrect result

The correct answer is Chloroplast.

Key Points

• Photosynthesis:
  • Photosynthesis definition states that the process exclusively takes place in the chloroplasts through photosynthetic pigments such as chlorophyll a, chlorophyll b, carotene, and xanthophyll.
  • All green plants and a few other autotrophic organisms utilize photosynthesis is to synthesize nutrients by using carbon dioxide, water, and sunlight.
  • The by-product of the photosynthesis process is oxygen.
  • Photosynthesis occurs when plants use light energy to convert carbon dioxide and water into glucose and oxygen.
  • Leaves contain microscopic cellular organelles known as chloroplasts.
  • Each chloroplast contains a green-colored pigment called chlorophyll.
  • Light energy is absorbed by chlorophyll molecules whereas carbon dioxide and oxygen enter through the tiny pores of stomata located in the epidermis of leaves.
  • Another by-product of photosynthesis is sugars such as glucose and fructose.
  • These sugars are used by the plants as an energy source, which helps them to grow.
  • Photosynthesis also applies to other organisms besides green plants.
  • These include several prokaryotes such as cyanobacteria, purple bacteria, and green sulfur bacteria.
  • These organisms exhibit photosynthesis just like green plants.
  • The glucose produced during photosynthesis is then used to fuel various cellular activities.
  • The by-product of this physio-chemical process is oxygen.

Concept-

• DNA stands for Deoxyribonucleic acid.
• DNA as an acidic substance present in the nucleus was first identified by Friedrich Meischer in 1869.
• He named it ‘Nuclein’.
• DNA acts as the genetic material in most organisms.
• A DNA molecule consisting of all the genetic material of an organism is known as a chromosome.
• These are thread-like (helical) structures of protein and nucleic acids which​ carry all the genetic information in the form of genes.

Explanation-

• ​Deoxyribonucleic acid (DNA) is a nucleic acid and is therefore made up of nucleotide.
• Each nucleotide consists of a phosphate group, a nitrogenous base (A, T, G, C), and ribose sugar (deoxyribose in case of DNA).
• A nucleoside contains only pentose sugar and a nitrogenous base.
• Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two types of nucleic acids found in living systems.
• DNA is a long polymer of deoxyribonucleotides.
• The length of DNA is usually defined as the number of nucleotides (or a pair of nucleotides referred to as base pairs) present in it.

Thereby DNA is composed only of nucleic acid.

Additional Information

Lipids: 

• ​These organic compounds are nonpolar molecules, which are soluble only in nonpolar solvents and insoluble in water because water is a polar molecule.
• In the human body, these molecules can be synthesized in the liver and are found in oil, butter, whole milk, cheese, fried foods, and also in some red meats.

Proteins:

• Proteins are composed of amino acids, arranged into different groups.
• These fundamental amino acid sequences are specific and their arrangements are controlled by the DNA. 
• These are the fundamental building blocks of our bodies.
• They are large and complex macromolecules or bio-molecules which perform a major role in the functioning and regulating of our body cells, tissues, and other organs in the human body.​