Year 8 Science Quiz With Answers

Electric current refers to the flow of electric charge, typically carried by electrons, through a conductor. It is the movement of these charged particles that allows electricity to flow and power electrical devices. Therefore, the given answer "Electric Current" accurately describes the flow of electricity.

The statement is true because a battery is often referred to as a cell. The term "cell" is commonly used to describe a single unit that generates electrical energy through chemical reactions, and a battery is made up of multiple cells connected together to provide a higher voltage. Therefore, the statement is correct.

The correct answer is organelles. Organelles are the specialized structures within a cell that perform specific functions. They are responsible for carrying out essential processes such as energy production, protein synthesis, and waste removal. Examples of organelles include the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. Unlike batteries, muscles, chloroplasts, and cell walls, organelles are the fundamental components of a cell that enable it to carry out its various functions.

In an electrical circuit, electrons, which are negatively charged, move within a conductor due to the attraction to the positive end of the battery and repulsion by the negative end. This movement establishes the flow of current in the circuit. Option A correctly describes the influence of the battery on electron movement.

A voltmeter is used to measure the amount of energy per second in a current. It measures the voltage or potential difference across a circuit, which indicates the amount of energy transferred per unit charge. By measuring the voltage, the voltmeter can determine the amount of energy being supplied or consumed by the current. An ammeter, on the other hand, is used to measure the current flowing through a circuit, while an elecmeter and switch are not instruments used for measuring energy per second in a current.

Iodine stain is used to make a wet mount slide. It is commonly used in microbiology to stain cells and make them more visible under a microscope. The stain helps to highlight the cellular structures and make them easier to observe and study. Water, urine, and coke are not typically used for making wet mount slides.

When a switch is open, it means that the circuit is not complete, and therefore, the flow of electricity is interrupted. As a result, the device or system connected to the switch will not function or work properly. Hence, the statement "It doesn't work" accurately describes the outcome when a switch is open.

The given answer is correct because cytoplasm, nucleus, and cell membrane are all found in both plant and animal cells. Cytoplasm is the gel-like substance that fills the cell and contains various organelles. The nucleus is the control center of the cell, containing the DNA. The cell membrane is the outer boundary of the cell, regulating the passage of substances in and out of the cell. These components are essential for the basic structure and function of both plant and animal cells.