True

Photosynthesis requires sunlight as a source of energy to convert carbon dioxide and water into glucose and oxygen. Since sunlight is available only during the day, the light-dependent reactions of photosynthesis occur during daytime. However, some processes like the Calvin cycle can continue briefly in the absence of light if energy molecules are available.

Metals generally have free electrons that can move easily, allowing them to conduct electricity efficiently. This is why metals like copper and aluminum are widely used in electrical wiring. However, the level of conductivity may vary among different metals.

The human heart consists of two atria (upper chambers) and two ventricles (lower chambers). This four-chambered structure helps in the efficient separation of oxygenated and deoxygenated blood, ensuring proper circulation throughout the body.

Sound requires a material medium (solid, liquid, or gas) to travel because it propagates through vibrations of particles. In a vacuum, where there are no particles, sound cannot travel. This is why space is completely silent.

At higher altitudes, atmospheric pressure is lower. Since boiling occurs when vapor pressure equals atmospheric pressure, water boils at a lower temperature in such conditions. This is why cooking takes longer in mountainous regions.

During photosynthesis, plants absorb carbon dioxide and release oxygen as a byproduct. However, plants do use oxygen during respiration, which occurs all the time, but photosynthesis specifically involves the intake of carbon dioxide.

The Earth’s orbit around the Sun is not perfectly circular but slightly elliptical (oval-shaped). This was explained by Johannes Kepler through his laws of planetary motion. The variation in distance is small but significant in astronomy.

Water is called a universal solvent because it can dissolve a wide variety of substances due to its polar nature. It can dissolve salts, sugars, gases, and many other compounds, making it essential for biological and chemical processes.

The speed of light (approximately 3 × 10^8 m/s) is much faster than the speed of sound (about 343 m/s in air). This is why we see lightning before we hear thunder during a storm.

Human somatic (body) cells contain 46 chromosomes arranged in 23 pairs. These chromosomes carry genetic information inherited from both parents and play a crucial role in determining traits and biological functions.