All Free Everyday Science MCQs with Answers

781. Reptiles hibernate during_______?

• A. Summer
• B. Winter
• C. Spring
• D. Autumn

Explanation: Reptiles are ectothermic, so their body temperature and activity fall when the surroundings become cold. They commonly enter winter dormancy or hibernation to conserve energy.

782. Which of the following plants are called arthrophytes?

• A. Sphenopsids
• B. Lycopsids
• C. Psilopsids
• D. Pteropsids

Explanation: Arthrophytes means jointed or joint-stemmed plants, a traditional name for the horsetails in the group Sphenopsida. Their jointed stems and whorled leaves distinguish them from the other listed plant groups.

783. Apiculture refers to___________?

• A. Rearing silk worms
• B. Science of bee keeping
• C. Science of gardening
• D. Science of cultural norms and trends

Explanation: Apiculture is the organised rearing and management of honeybees for honey, wax and other products. Rearing silkworms is called sericulture.

784. Ozone layer protects the Earth from __________ radiations from the Sun.

• A. microwaves
• B. infrared
• C. X-rays
• D. ultraviolet

Explanation: Stratospheric ozone absorbs most of the Sun's harmful ultraviolet radiation, especially UV-B and UV-C. It does not primarily block microwaves or infrared rays.

785. Which layer of the atmosphere reflects radio waves back to the earth's surface?

• A. Troposphere
• B. Stratosphere
• C. Ozone layer
• D. Ionosphere

Explanation: The ionosphere contains electrically charged particles that can reflect or refract certain radio waves back toward Earth. The troposphere and stratosphere do not generally perform this role.

786. What is known the cold and dense air blowing down from the mountain slope during the night__________?

• A. Anabatic Wind
• B. Katabatic wind
• C. Lue Wind
• D. None of these

Explanation: A katabatic wind is cold, dense air that flows downhill under gravity, commonly from mountain slopes at night. Anabatic winds move uphill as heated air rises during the day.

787. The disease "Itai Itai "is caused by____________?

• A. Carbon
• B. Cadmium
• C. Manganese
• D. None of these

Explanation: Itai-itai disease is a severe form of cadmium poisoning, historically linked with contaminated rice and water in Japan. The name refers to the painful bone damage caused by the disease.

788. Most of the weather phenomena take place in which of the following layers of the atmosphere?

• A. Mesosphere
• B. Ionosphere
• C. Stratosphere
• D. Troposphere

Explanation: The troposphere is the lowest atmospheric layer and contains most of the air, water vapour, clouds, and weather processes. The stratosphere lies above it and is comparatively stable.

789. Granite is a____________?

• A. Metamorphic rock
• B. Igneous rock
• C. Sedimentry rock
• D. None of these

Explanation: Granite forms when molten magma cools and solidifies slowly beneath Earth’s surface, producing a coarse-grained intrusive igneous rock. It is not sedimentary or metamorphic rock.

790. Earth is divided into following three layers?

• A. Crust, Mountains, Oceans
• B. Crust, Mantle, Trenches
• C. Trenches, Mountains, Core
• D. Crust, Mantel, Core

Explanation: The broad internal divisions of Earth are the crust, mantle and core. Option d contains a spelling error, writing “Mantel” instead of “Mantle,” but it is clearly the intended answer.