Science in Class 10 : Practice MCQ Questions & Answers with Explanations

Meiosis reduces the chromosome number by half, ensuring gametes (sperm and egg) can combine during fertilization without doubling the chromosome count.

Sulphur, phosphorus, and nitrogen are all essential nutrients used in fertilizers to improve soil fertility and enhance plant growth.

Fertilization is the process in which a male gamete (sperm) fuses with a female gamete (egg) to form a zygote, initiating the development of a new organism.

Xylem is the plant tissue responsible for transporting water and dissolved minerals from the roots to the rest of the plant.

The kidneys filter waste products and excess substances from the blood to form urine, playing a crucial role in maintaining the body's fluid and electrolyte balance.

Ethanol ($C_2H_5OH$) is an alcohol, characterized by the hydroxyl group (-OH) attached to a carbon atom. It is widely used in beverages, disinfectants, and as a biofuel.

Copper is preferred for electrical wiring due to its high electrical conductivity, ductility, and resistance to corrosion, making it ideal for efficient energy transmission.

Rust, chemically hydrated iron(III) oxide, forms when iron reacts with water and oxygen in the presence of moisture. This process is called corrosion.

When acids react with metals, hydrogen gas is released along with a corresponding salt. For example, zinc reacts with hydrochloric acid to produce hydrogen gas and zinc chloride.

When hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), it forms sodium chloride (NaCl) and water. This is a neutralization reaction.

A combination reaction occurs when two or more reactants combine to form a single product. It is one of the basic types of chemical reactions.

Burning wood involves a chemical reaction where new substances such as carbon dioxide, water vapor, and ash are formed, releasing energy as heat and light.

Vitamin C, also known as ascorbic acid, is crucial for collagen production, wound healing, and immune support. It is commonly found in citrus fruits.

Vaccines contain weakened or inactivated pathogens or their components to stimulate the immune system, creating immunity without causing disease.

Hemoglobin is a protein in red blood cells that binds oxygen in the lungs and carries it to tissues. It also transports carbon dioxide back to the lungs for exhalation.

A concave lens is used to correct myopia (short-sightedness). It diverges incoming light rays to help them focus correctly on the retina.

Pure water is neutral with a pH of 7 at 25°C. Below 7 is acidic and above 7 is basic.

Carbon dioxide traps heat in the Earth's atmosphere, contributing to the greenhouse effect and global warming.

Asexual reproduction involves only one parent and produces offspring that are genetically identical. Methods include binary fission, budding, and vegetative propagation, and no specialized reproductive organs are required.

The cerebellum controls balance, coordination, and fine motor skills. It processes sensory information and adjusts movement for smooth, coordinated actions.