Question Discussion & Solution

Concept-

• Roots are the underground structures that help in the absorption of water and minerals, provide a proper anchorage to the plant parts, storage of reserve food material (Carrot, Radish), and synthesis of PGR (plant growth regulators).
• Sometimes roots get modified to perform different functions like Storage of food, respiration, climbing, etc.
• These types of roots are called modified roots.

Explanation-

• The Coralloid roots are the specialized roots found in cycas, these roots exhibit a symbiotic relationship between the cyanobacteria and cycas where the cyanobacteria fix the nitrogen and in return, the cycas provide a stable environment to live.
• Cycas, a genus of 105 species of palmlike tropical and subtropical ornamental cycads (family Cycadaceae), among them trees 12 meters (40 feet) or more in height. 
• Their leaves are dark green and circinate (uncoiling as fern leaves do), differing from those of other members of the family in having a midrib but no lateral veins. 
• The seeds are borne along the margins of modified leaves, which are arranged in a whorl at the top of the trunk, rather than in compact cones. 

Thereby coralloid roots are found in cycas.

Additional Information

• Lycopodiopsida
  • It is a class of herbaceous vascular plants known as lycopods, lycophytes.
  • Members of the class are called clubmosses, firmosses, and quillworts.
• Pine
  • A pine is any conifer in the genus Pinus of the family Pinaceae. Pinus is the sole genus in the subfamily Pinoideae.
• Dryopteris
  • It is commonly called the wood ferns, male ferns, or buckler ferns is a fern genus in the family Dryopteridaceae.​

Concept:

• Electroscope:
  • It is an early scientific instrument used to detect the presence of an electric charge on a body.
  • The first electroscope was a pivoted needle electroscope invented in the year 1600 by British Physicist William Gilbert.
  • It measures the charge that is dependent on the Coulomb electrostatic force that triggers the movement of the test charge.

Explanation:

• Seismograph:
  • It is an instrument that is used to detect and record earthquakes. generally, it consists of a mass attached to a fixed base. During an earthquake, the base moves and the mass does not.
• Ammeter:
  • This is a meter that is used for measuring electric current. Current is the flow of electrons whose unit is ampere.
  • Hence the instrument which measures the flow of current in ampere is called as Ampere meter or ammeter.
  • the ideal ammeter has zero internal resistance.
• Voltmeter:
  • It is an instrument used for measuring the electric potential difference between two points in an electric circuit that is connected in parallel. 
  • It usually has high resistance so that it takes negligible current from the circuit.
•  An electroscope is a correct answer.

Explanation:

Composting is one of the options for the treatment of solid waste. In the composting process, the organic matter breaks down under bacterial action resulting in the formation of humus like material called compost.

• Vermicomposting: It involves the use of earthworms for composting organic solid waste. It is a resourceful way to recycle your food waste into compost. It takes about 2-3 months.
• Vermicompost (worm manure) is the end-product of the breakdown of organic matter by earthworms. 
• This process of increasing the fertility of soil by earthworms is known as vermicomposting.

Hence, fertilizer produced by the earthworm is called Vermicompost.

Additional Information

Biofertilizers: 

• ​Is a substance that contains living micro-organisms that, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. 
• Biofertilizers add nutrients through the natural processes of Nitrogen fixation.
• Examples: Rhizobium, Azotobacter, Blue-green algae, Azospirilium.

Nitrogen fertilizer:

• Urea, also known as carbamide, is an organic compound with the chemical formula CO(NH₂)₂.
• This amide has two –NH₂ groups joined by a carbonyl functional group.
• Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals.
• The main function of Urea fertilizer is to provide the plants with nitrogen to promote green leafy growth and make the plants look lush.
• Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use.

CONCEPT:

• Power is the ability to bend light and it is equal to the reciprocal of the focal length of the lens/mirror in meters.

Power (P) = 1/f

Where f is the focal length of the lens/mirror.

EXPLANATION:

As explained above, Dioptre is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres.

And since the S.I unit of the focal length is the meter (m).

So the S.I unit of power = 1/(SI unit of focal length) = m-1 = Dioptre (D).

1 m-1 = 1 D

Least possible diagram is:

I. Some car are Maruti. → True

II. No Ciaz is a Maruti. → False