Year 4 Science Quiz Questions And Answers!

A thermometer is used to measure temperature. It consists of a glass tube filled with a liquid, usually mercury or alcohol, that expands or contracts with changes in temperature. The liquid rises or falls in the tube, indicating the temperature. By observing the level of the liquid, the temperature can be measured accurately. Using a microscope or a telescope is not a suitable method for measuring temperature.

The skull protects the brain. The brain is a vital organ responsible for controlling the body's functions, processing information, and coordinating movement. The skull acts as a protective barrier, shielding the brain from external impact and injury.

Snail does not have a skeleton. Unlike dogs, fish, and horses, snails belong to a group of animals called mollusks, which typically have a soft body protected by a hard shell. However, this shell does not function as a skeleton in the same way that bones do. Instead, the snail's shell provides support and protection, but it is not a rigid structure that supports the body's movements. Therefore, the snail is the correct answer as it is the only animal listed that does not have a skeleton.

The skeletal system's primary function is to support the body's structure, protect vital organs, and enable movement by working with muscles. Bones act as a framework that gives the body its shape, while joints and muscles work together to allow motion. Additionally, the skeletal system produces blood cells in the bone marrow and stores essential minerals like calcium, making it crucial for overall health and bodily functions.

Snails are classified as invertebrates because they do not have a backbone or a vertebral column. Invertebrates are animals that lack a spinal column, and instead have other structural support systems. Snails have a soft body protected by a hard shell, but they do not possess a backbone like vertebrates do. Therefore, the correct answer is that a snail is an invertebrate.

A textbook is solid because it has a definite shape and volume. Unlike oxygen, which is a gas, fizzy lemonade and milkshake, which are liquids, a textbook maintains its form and does not flow or take the shape of its container.

Thermal conductivity is the ability of a material to transfer heat. Good thermal conductors allow heat to pass through them easily. Aluminum is an excellent thermal conductor, which is why it is used in cookware, heat sinks, and other applications where efficient heat transfer is desired. Rubber, wood, and glass are thermal insulators, meaning they resist the flow of heat.

Frogs are classified as vertebrates because they have a backbone or a spinal column. Vertebrates are animals that possess a well-developed internal skeleton made of bones or cartilage, which includes a backbone. This structure provides support and protection for the frog's body and allows for movement. Therefore, the correct answer is that a frog is a vertebrate.

Orange juice is a liquid because it is a fluid substance that can flow and take the shape of its container. It does not have a fixed shape or volume, and it is not solid like a pencil, ice cube, or pen.

Melting is the correct answer because it refers to the process of turning a solid, such as an ice cube, into a liquid, in this case, water. The process of melting occurs when heat is applied to the solid, causing the particles to gain energy and move more rapidly, breaking the bonds that hold them together in a solid state. As a result, the ice cube transitions into a liquid state, becoming liquid water.

Using a sieve is the correct answer because it is a common and effective method for separating stones from soil. A sieve consists of a mesh screen that allows smaller particles like soil to pass through while retaining larger particles like stones. By pouring the soil onto the sieve and shaking it, the stones will be left behind on top of the sieve while the soil falls through. This process helps to remove unwanted stones from the soil, making it more suitable for gardening or other purposes.

Freezing is the process of turning water from a liquid to a solid state, resulting in the formation of an ice cube. During freezing, the water molecules lose energy and slow down, causing them to arrange themselves into a solid structure. This process occurs when the temperature of the water drops below its freezing point, which is 0 degrees Celsius or 32 degrees Fahrenheit.

Sand cannot dissolve into water because it is composed of large, solid particles that do not have the ability to separate and disperse into the water molecules. In contrast, coffee, salt, and sugar are all soluble in water, meaning they can dissolve and form a homogeneous mixture with the water molecules.

Leaves are the primary sites of photosynthesis in plants. They contain chlorophyll, a green pigment that absorbs sunlight, which is the energy source for photosynthesis. The leaves also have tiny pores called stomata that allow for the exchange of gases, such as carbon dioxide and oxygen, which are essential for the process.

The primary function of muscles in the human body is to create movement. Muscles work by contracting (shortening) and relaxing (lengthening), which allows different parts of the body to move. This function is essential for walking, running, jumping, and even for movements as fine as writing with a pencil.

Plants make their own food through a process called photosynthesis. For photosynthesis to occur, plants need three main ingredients: water (which they absorb through their roots), air (specifically carbon dioxide from the air), and sunlight (which they capture using chlorophyll in their leaves). The combination of these elements allows plants to produce glucose, which they use for energy and growth, and oxygen, which they release into the atmosphere. Soil is important for anchoring plants and providing nutrients, but it is not a direct component of photosynthesis.

While many living things can move, movement is not a universal characteristic of life. Plants, for example, are rooted in place and cannot move freely. However, all living things grow and develop, reproduce, and respond to stimuli in their environment.