The physical quantity measured in kg·m/s² is Force. The SI unit of force is the Newton (N), which is defined as the force required to accelerate a mass of 1 kilogram by 1 meter per second squared. Mathematically, Force = Mass × Acceleration.

• Work: Measured in joules (N·m).
• Power: Measured in watts (J/s).
• Motion: Describes movement, not a measurable quantity in these units.

Explanation: Photosynthesis is the process by which green plants, algae, and some bacteria use sunlight to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). This process takes place in the chloroplasts of plant cells, which contain the green pigment chlorophyll that captures solar energy.

Chemical Equation:

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Thus, plants are known as autotrophs because they produce their own food using light energy — a process vital for sustaining all life on Earth.

Explanation: A lens is generally made of flint glass, which contains lead oxide. Flint glass has a higher refractive index than ordinary glass, allowing it to bend light more effectively. This property makes it ideal for manufacturing optical instruments such as lenses and prisms.

Insecticides primarily act upon the nervous system of insects. They interfere with the transmission of nerve impulses, leading to paralysis and ultimately death. Common insecticides like organophosphates and carbamates inhibit the enzyme acetylcholinesterase, causing continuous nerve stimulation. Some others, like pyrethroids, disrupt sodium channel functioning in nerve cells.

Other options (for context)

• Muscular system: Indirectly affected due to nerve failure, but not the primary target.
• Digestive system: Rarely affected — insecticides mainly disrupt neural signaling, not digestion.

Explanation: Vitamin B₂ is also known as Riboflavin. It is a water-soluble vitamin that plays a vital role in the body’s energy production and cellular function. Riboflavin acts as a coenzyme in the metabolism of carbohydrates, fats, and proteins, helping to convert food into energy. It is also essential for maintaining healthy skin, eyes, and nerve functions. A deficiency of Vitamin B₂ can lead to cracked lips, sore throat, and inflammation of the tongue (a condition known as ariboflavinosis).

Explanation: Mitochondria are double-membraned organelles found in almost all eukaryotic cells. They are known as the 'power house of the cell' because they generate adenosine triphosphate (ATP) through the process of cellular respiration. The inner membrane forms folds called cristae, which increase the surface area for enzyme activity related to energy production. Mitochondria also contain their own DNA and ribosomes, enabling them to produce some of their own proteins.

Key Reaction:

Glucose + Oxygen → Carbon dioxide + Water + ATP

Explanation: Animals that live in or on trees are called arboreal animals. They are adapted to climbing and moving about among branches. Examples include monkeys, squirrels, chameleons, and tree frogs. Their adaptations may include grasping limbs, prehensile tails, claws, or adhesive pads that help them cling to tree surfaces and move efficiently among branches.

Brown is not seen in a rainbow. A natural rainbow displays seven distinct colours — Violet, Indigo, Blue, Green, Yellow, Orange, and Red (VIBGYOR). These colours appear due to the dispersion of sunlight by water droplets in the atmosphere, but brown is not part of the visible spectrum formed by dispersion.

• Yellow, Green, Red: All are part of the seven colours of the rainbow.