BPSC Prelims Past Year Paper- 2023 - BPSC (Bihar) MCQ

The correct answer is cartilage.

Key Points

• The human skeleton system consists of bones and cartilage.
• It protects internal organs and provides support to the body.
• Cartilage is a type of connective tissue.
• Cartilage consists of chondrocytes.
• It is flexible and also acts as a shock absorber.
• The parts of the skeleton that are not as hard as bones and which can be bent are called cartilage.
• It is present in the outer ear and tip of the nose.
• It also forms joints and aid in locomotion.

The correct answer is alga and a fungus.

Key Points
Lichen

• It is a symbiotic relationship between algae and fungi.
• The fungus provides a stable surface for the algae to grow on.
• The algae produce food for both partners through photosynthesis.
• This mutualistic relationship allows lichen to survive in harsh environments, such as rock surfaces and tree bark.
• The fungal component of lichen is responsible for
  • retaining moisture and
  • protecting the algae from harmful UV rays.
• The algae component provides the energy needed for
  • growth and
  • reproduction
• This unique symbiosis relationship between algae and fungus sets lichen apart from other forms of plant life.

The correct answer is at an angle with substratum.

Key Points

• Mosquito is a vector and transmits the disease.
• Insects, when fed on human blood transmit the pathogen.
• Anopheles transmits malaria parasites.
• Culex transmits the west nile virus and filarial nematodes.
• There are differences between female culex and female anopheles in their feeding pattern, size, eggs, and habitat.
• Female Anopheles body rests at an angle to the substratum Culex body rests parallel to the substratum.
• Anopheles mosquito makes angles its body at 45 degrees from the surface.

The correct answer is lymphocytes.

Key Points

• Immunity is protection from infectious agents.
• The immune system consists of cells that kill the invading pathogen.
• Our body comprises lymphocytes, monocytes, neutrophils, eosinophils and basophils.
• Lymphocyte is a type of agranulocyte.
• It is B-Lymphocyte and T-lymphocytes.
• T-lymphocytes help in the production of antibodies,  killing the pathogen.
• B-lymphocytes produce antibodies and bind with a foreign antigen.
• The most important cell type associated with the immunity of the body is lymphocytes.
• Lymphocytes are formed inside bone marrow by hematopoiesis.
• T-lymphocytes mature in the thymus, and B- lymphocytes differentiate and mature inside the bone marrow itself.

The correct answer is Muscles can only push the bone.

Key Points

• Muscles are part of the human skeletal system.
• Myofibers form muscles and parallel bundles of myofibrils form these muscles.
• Muscles consist of various proteins such as actin, myosin, troponin, and tropomyosin.
• It helps in locomotion.
• Muscles can pull not push.
• It is because muscles contract with the help of proteins actin and myosin.
• Muscles work in pairs.
• One muscle contracts and the other relaxes, thus working in pairs.
• Muscles get shorter, stiffer, and thicker when contracted.
• The length of sarcomere shortens while contracting.
• Muscles become longer and thinner while relaxing.

The correct answer is a horse of less brightness.

Key Points

• An image of a white horse is captured by the convex lens.
• Since the light falling on the curved portion won't react at the picture point, the white horse's entire image is produced, but its intensity is reduced.
• A horse of less brightness is produced by the lens.

Convex Lens:

• The convex lens is relatively thick in the center and thin at the lower and higher borders.
• It converges light rays that travel parallel to its principal axis. 
• Instead of curving inside, the edges are curled outward.

Concave Lens:

• A concave lens has thicker edges and a thinner center.
• It is one that bends a straight light beam away from the source and focuses it into a distorted, upright virtual image.

The correct answer is wavelength of sound.

Confusion Points

• It is true that the shrillness of sound is determined by its frequency but frequency and wavelength are inversely proportionate. So, it is also true to say that the shrillness of sound depends on its wavelength.
• Since frequency and wavelength are inseparably interlinked (velocity= wavelength x frequency and velocity are constant in a medium).

Key Points

• The Shrillness of the sound is determined by the frequency of the vibration.
• High-pitched noises can be characterized as having a shrill quality.
• We describe a sound as being harsh and having a higher pitch if the vibration frequency is higher. 
• Low pitch is a description of a sound whose vibration frequency is lower.
• Pitch can be thought of as the unit of measurement for sound frequency expressed in Hertz.

The velocity of Sound:

• The distance that sound energy will travel through that material in a specific amount of time. 
• It depends on the material's density, acoustic impedance, and temperature.

The amplitude of Sound:

• The height of a sound wave is quantified by its amplitude.
• The loudness or the maximum displacement of vibrating medium particles from their mean position at the time the sound is produced.

Wavelength of Sound:

• The distance separating two wave crests or troughs that occur consecutively.

The correct answer is Photovoltaic cell.

Photovoltaic cell:

• A photovoltaic panel usually referred to as a module, is a structure made up of connected unique cells that produce an electric current when exposed to sunlight.
• An electric field is produced when the cells are exposed to the sun.
• Photovoltaic cells or commonly known as solar cells have vast use in digital technology.
• For example entire satellite communication depends on it since this is the main source of power for it.

The correct option is rolling friction.

Ball Bearings:

• A device known as a ball-bearing is made up of two rings and two freely moving metal balls.
• It is intended to prevent sliding by forcing a machine's moving elements to roll over one another.
• The static friction is changed into rolling friction by them.

 

The correct option is decrease the rate of change of momentum.

Key Points

• The ball's time being held by the goalkeeper extends. By extending the period of time, he decreases the force rate of change of momentum that the football exerts on him.

Second Law of Motion by Newton:

• According to the second rule of motion, a body's force is equal to the product of its mass and acceleration.
• The rate at which momentum changes is the same as force.
• Force is defined as mass times acceleration for a constant mass.
• The above condition of the goalkeeper is an example of the second law of motion.

The correct answer is -Alpha ray.
Key Points
Alpha Ray

• Alpha rays are positively charged particles consisting of two protons and two neutrons.
• They are produced through the decay of heavy, unstable atomic nuclei and are emitted in a narrow, straight path.
• They were first discovered in the late 19th century by Ernest Rutherford.
• Alpha rays play a critical role in studying the nature of the atomic nucleus and nuclear physics.
• Alpha rays are produced during alpha decay when a nucleus has too many protons and too little binding energy to hold them together.
• The nucleus will emit an alpha particle, reducing the number of protons and increasing the stability of the atom.
• Alpha rays are highly ionizing.
• They can cause significant damage to living tissues if they come into direct contact.
• Alpha rays are very short-range, typically only traveling a few centimeters in the air.

The correct option is keep the body moving along the circular path.

Centripetal Force:

• Centripetal force is a force that acts on a body traveling in a circle and is aimed at the center of the body's motion.
• Its movement is orthogonal at a right angle to the body's motion in the direction of the body's path's center of curvature.
• It keeps the body moving along a circular path.

The correct option is Kinetic energy to heat energy.

Key Points

• Energy transition entails Friction converting kinetic energy into heat energy.
• Friction between two surfaces causes kinetic energy from moving surfaces to be converted into thermal energy.
• The utilization of friction is produced by rubbing pieces of wood together to start a fire.

The correct option is bent towards left side.

Key Points

• A bus is moving along a straight path and takes a sharp turn to the right side suddenly. The passengers sitting on the bus will bend towards the left side.
• The lower portion of passengers closest to the bus tends to go in the direction of the sharp turn because of centripetal force, but the upper portion of passengers throws an outside centrifugal force.
• This is happening due to two forces that are acting at that time centripetal and centrifugal forces.

The correct option is the frequency of the sitar string with the frequency of other musical instruments.

Key Points

• Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he/she is adjusting the frequency of the sitar string.

The correct option is kerosene.

Key Points

• A form of matter has no fixed shape but it has a fixed volume. An example of this form of matter is kerosene.
• The state of matter with a definite shape and volume is called solid.
• The state of matter which has no definite shape but has a definite or fixed volume is called liquid.
• The state of matter which has no definite shape and no definite volume is called gas.
• Kerosene is a substance that is present in a liquid state thus, it has a definite volume but no actual shape.

The correct option is Al₂O₃ and ZnO.

Key Points

• Some metal oxides react with acid as well as a base to produce salt and water. They are known as amphoteric oxides. Examples of amphoteric oxides are Al2O3 and ZnO.
• The oxides can act both as acidic and basic amphoteric oxides.
• Amphoteric oxides are also able to neutralize both acid and base.
• These oxides on mixing with water can produce an alkaline solution.
• Oxides like Al₂O₃, PbO, SnO, ZnO, etc. are amphoteric oxides.
• Example: Al₂O₃ in reaction with acid like hydrochloric acid can produce aluminum chloride i.e. salt and water.
• Al₂O₃(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂O(l)
• ZnO in reaction with a base like sodium hydroxide can produce sodium zinc oxide and water.
• ZnO(s) + 2NaOH(aq) → Na₂ZnO₂(aq) + H₂O(l)

The correct answer is -More than one of the above.

Key Points
Gases causing the greenhouse effect

• The greenhouse effect is a phenomenon where certain gases in the Earth's atmosphere trap heat from the sun and warm the planet. 
• These gases are known as greenhouse gases and include
  • carbon dioxide (CO₂),
  • methane (CH₄),
  • nitrous oxide (N₂O),
  • fluorinated gases, and
  • water vapour. 
• Carbon dioxide (CO₂) and methane (CH₄) are two of the most significant greenhouse gases
• They are major gases that contribute to global warming.
• They trap heat in the atmosphere and prevent it from escaping into space.
• This heat trapping leads to an increase in global temperatures. 
• The following activities produce large amounts of greenhouse gases
  • burning of fossil fuels such as coal and oil produces large amounts of CO₂
  • Agricultural practices and the digestive processes of livestock emit a significant amount of CH₄
  • N₂O emissions include the burning of fossil fuels, industrial processes such as nitric acid production, and the degradation of organic matter in the soil.

The correct answer is CO₂.

Key Points
Acid reaction with metal carbonates

• Acids react with metal carbonates to liberate carbon dioxide gas.
• The reaction occurs because
  • the hydrogen ions from the acid react with the metal ions in the carbonate to form water, and
  • the carbonate ion reacts with the hydrogen ion to form carbon dioxide.
• The balanced chemical equation for this reaction can be written as:
  • Metal Carbonate + Acid → Salt + Carbon Dioxide + Water
• The carbonate ion reacts with the hydrogen ion to produce carbon dioxide gas and water.
• This reaction is exothermic.
• it releases heat energy and is a classic example of an acid-base reaction.
• The amount of carbon dioxide produced is proportional to the amount of acid used in the reaction.
• It can be measured by collecting the gas produced and weighing it.

The correct answer is -Oxalic acid.

Key Points
Oxalic Acid:

• It has an empirical formula of C₂O₄H₂ or HOOCCOOH.
• It is a strong, dicarboxylic acid that is widely used as a cleaning agent, bleach and rust remover.
• It is also found in almost all living organism that uses Kreb's cycle.
• It can form highly toxic salts such as oxalates, which can cause kidney damage if ingested in large quantities.
• It is a colourless, crystalline solid that is soluble in water.

The correct option is base.

Key Points

• The basic solution can turn red litmus to blue.
• Add a few drops of solution from each text tube on litmus paper.
• The distilled water is neutral in nature and thus on adding it to litmus paper there is no color change in litmus paper. 
• With the addition of a few drops of acidic solution on blue litmus paper, the litmus paper turns blue to red.
• With the addition of a few drops of basic solution on red litmus paper, the litmus paper turns red to blue.

The correct answer is -vinegar.

Key Points

• Odour of acetic acid
• It primarily resembles vinegar. 
• Acetic acid is a colourless liquid
• It has a sharp, pungent smell and sour taste.
• The concentration of acetic acid in vinegar can range from 4 to 8 per cent, with higher concentrations resulting in a stronger smell.
• The smell is so strong because of the volatile nature of acetic acid.

The correct option is no H3O+ ions are present. Litmus changes color only in the presence of H3O+ ions.

• Dry HCI gas does not change the color of dry litmus paper because no H₃O⁺ ions are present.
• Litmus changes color only in the presence of H₃O⁺ ions.
• Dry HCl is not able to dissociate to give Hydrogen ions. 
• Acids like HCl is only able to dissociate only in an aqueous medium.
• HCl is not aqueous and not the litmus paper is wet.
• Thus, there is no color change in litmus paper.

The correct option is the Option E.

Water and cement initially form a cement paste that begins to react and harden (set).

• This paste binds the aggregate particles through the chemical process of hydration. In the hydration of cement, chemical changes occur slowly, eventually creating new crystalline products, heat evolution, and other measurable signs.
• Setting of cement is an example of permanent change which is irreversible, hence is not a physical change.

The correct option is none of the above.

• Graphite and diamond are made up of carbon elements.
• They are allotrophs of carbon.
• Graphite and diamond are able to show similar chemical characteristics.
• Thus, they can show the same chemical changes.
• Graphite is present in sheets or layers of carbon atoms that are weakly bonded to each other.
• Diamond has a strong 3-dimensional arrangement of carbon atoms and is hard in nature.

The correct answer is -amount of water in cells.
Key Points

• Stomata opening and closure is a process that regulates gas exchange and water balance in plants.
• The process is controlled by two main cells called the guard cells.
• Guard cells are located around the stomatal pore and are responsible for opening and closing the pore.
• The water uptake controls the opening of the stomata by the guard cells
• It leads to turgor pressure and an increase in the size of the guard cells.
• This causes the stomata to open and allow the exchange of gases
• Gases such as carbon dioxide and oxygen are exchanged between the plant and the atmosphere.
• The stomata's closure results from water loss from the guard cells and a decrease in turgor pressure.
• This causes the guard cells to shrink, resulting in the stomata closing
• Nucleus position and protein composition do not have any major effect on the stomata closure and opening.

The correct answer is -red and blue.

Chlorophyll

• Chlorophyll is the pigment found abundantly in green plants.
• It absorbs most efficiently in the blue and red regions of the visible light spectrum.
• Sunlight contains a large spectrum of light from red to blue spectrum, including green light.
• Chlorophyll absorbs light in the
  • blue region of the spectrum the most, with peaks around 450 and 650 nanometers
  • The absorbed red light with a peak at 700 nanometers.
• The green region of the spectrum is reflected, giving chlorophyll its green color.
• Chlorophyll a and b are the most abundant types of chlorophyll.
• Other pigments found in plants, such as carotenoids and phycobilins, also absorb light in different regions of the spectrum
• If the plants have large amounts of carotenoids, they appear red as they reflect red light.

Option 2 is not a correct match.

Key Points

• Plants are the producers on earth.
• It varies in size from small herbs and shrubs to tall trees.
• Levaes flatter in wind and are the sites where photosynthesis takes place.
• Leaves consist of leaf base and lamina.
• Leaves attach to the stem by the petiole,
• It is a small stalk-like structure that helps in attachment to the stem.
• Creeper has a weak stem, and it cannot stand upright, and is present on the ground.
• Pumpkin and watermelon are examples.
• A tree is a thick, hard stem with branches high on the plant.
• Banyan and neem are examples.

The correct answer is transpiration.

Key Points

• Plants are immobile and do not move.
• Plants are characterized by vascular tissue that aids in the movement of water and sucrose.
• Plants absorb water from roots and carry it with the help of xylem tissue.
• Transpiration is the removal of water from parts of plants, such as leaves.
• The water reaches great heights in trees because of suction pull caused by transpiration.
• It occurs via the stomatal opening.
• It helps in the maintenance of water inside the plant body.

The correct answer is the Presence of both DNA and RNA.

Key Points

• Chloroplast is a green color plastid present inside a plant cell.
• Chloroplast is a double membrane structure.
• It is semiautonomous, and it has its DNA.
• DNA can replicates and forms its copy.
• Replication is a process in which DNA forms its copy with the help of a DNA template and the enzyme DNA polymerase.
• Chloroplasts contain their own DNA, which is separate from the nuclear DNA found in the cell's nucleus. While the presence of DNA is an important factor in chloroplast replication, it is not sufficient for self-replication.
• Both DNA and RNA play important roles in the self-replication of chloroplasts, which are organelles found in plant cells that are responsible for photosynthesis.​ 
• Chloroplasts contain their own DNA, which encodes for some but not all of the proteins required for their replication and functioning.
• In order for the proteins to be produced, the DNA must first be transcribed into RNA, which serves as a template for protein synthesis.
• DNA provides the genetic information required for chloroplast replication, while RNA molecules are involved in the transcription of genetic information into proteins. Both DNA and RNA are essential for the self-replication of chloroplasts.