Explanation

• The pupil is the small, circular opening in the center of the iris that appears as a black dot.
• It is the entrance point for light to enter the eye.
• It is responsible for controlling the amount of light that enters the eye by changing its size.

Explanation

• The cell wall is a thick, permeable layer that surrounds the plant cell.
• It provides support, protection, and shape.
• It is composed of cellulose, hemicellulose, and pectin.
• It is responsible for maintaining the cell's rigidity and structure.

Explanation

• Chlorophyll is the green pigment found in chloroplasts.
• It responsible for absorbing light energy and playing a central role in photosynthesis.

Explanation

• The eardrum (tympanic membrane) converts sound waves into mechanical vibrations.
• Which are then transmitted through the middle ear bones (ossicles) to the inner ear.

Explanation

• The pupil is the small opening in the center of the iris that changes size to regulate the amount of light entering the eye.
• It acts like a camera aperture, opening or closing to control the amount of light that enters the eye.

Explanation

• In both microscopes and human eyes, the iris (or diaphragm) controls the amount of light that enters the instrument or eye.
• In microscopes, it regulates the amount of light that reaches the objective lens.
• While in human eyes, it regulates the amount of light that enters the pupil.

Explanation

When an object is placed very close to a concave mirror, its image will be:

• Virtual (not a real image that can be projected onto a screen)
• Upright (not inverted)
• Larger in size than the object (magnified)

Explanation

• Potential energy is a measure of the energy an object has due to its position or state, and it determines how much work the object can perform.
• The amount of potential energy an object has is a function of its mass, height, and other factors.
• It can be converted into kinetic energy (the energy of motion) when the object is released or moved.
• For example, a ball at the top of a hill has a certain amount of potential energy due to its height, and as it rolls down the hill, this potential energy is converted into kinetic energy, allowing the ball to perform work (such as moving down the hill).

Explanation

• Thermal energy is the form of energy that is transferred from one body to another due to a difference in temperature, and is received from heat.
• It is the energy of motion of particles in a substance, such as atoms or molecules, and is often referred to as "heat energy".

Explanation

• The lightest gas used for filling party and advertisement balloons is hydrogen.
• However, due to its flammability, helium is more commonly used despite being slightly heavier, because it is safe and non-reactive.