All Free Everyday Science MCQs with Answers

661. Which is the New & Most Important Culprit damaging the ozone Layer?

• A. Carbon Dioxide
• B. Chlorofluoro Carbons
• C. Nitrous Oxide
• D. Carbon Monoxide

Explanation: Although CFCs caused the historic ozone hole, nitrous oxide is now regarded as the leading human-emitted ozone-depleting substance because it continues to reach the stratosphere in large amounts. It produces reactive nitrogen compounds that destroy ozone.

662. The color of a sedimentary rock is often mostly determined by___________?

• A. Zinc
• B. Iron
• C. Calcium
• D. None of these

Explanation: Iron compounds, especially iron oxides, commonly give sedimentary rocks red, brown, yellow, or orange shades. Zinc and calcium may occur in rocks but do not usually dominate their overall colour.

663. Carpology is a discipline devoted to the study of what?

• A. Corbons
• B. Cubes
• C. Seeds and fruits
• D. Infertile soils

Explanation: Carpology is the branch of botany concerned with fruits and seeds, including their structure and development. The term comes from Greek words associated with fruit.

664. Which insect can survive without a head for one or more weeks?

• A. Ladybird
• B. Bee
• C. Cockroach
• D. Termite

Explanation: Cockroaches can survive for weeks after losing their heads because they breathe through body openings and have a simple circulatory system. They eventually die mainly from starvation or dehydration.

665. What time of day do most owls hunt?

• A. Morning
• B. Afternoon
• C. Evening
• D. Night

Explanation: Most owl species are nocturnal, meaning they are most active and hunt at night. Some species hunt during the day or at twilight, but night is the standard answer.

666. Who keeps blind snakes as their pets?

• A. Woodcutters
• B. Eagles
• C. Parrots
• D. Owls

Explanation: Burrowing owls bring blind snakes into their underground nests, where the snakes help consume insect larvae and other small prey. This unusual relationship is popularly described as the owl keeping the snakes as pets.

667. Composition of Ozone layer?

• A. O1
• B. O2
• C. O3
• D. O4

Explanation: Ozone is a molecule made of three oxygen atoms, so its chemical formula is O3. Ordinary oxygen gas is O2, which is why O2 is not the composition of the ozone layer.

668. Where do the Prime Meridian and the equator intersect each other point?

• A. Arabian Peninsula
• B. Malacca Strait
• C. Gulf of Guinea
• D. All of These

Explanation: The Prime Meridian is 0° longitude and the equator is 0° latitude; their intersection lies in the Gulf of Guinea off the west coast of Africa. It is not on the Arabian Peninsula or in the Malacca Strait.

669. The main factor for determining a region's climate is ___________?

• A. Latitude
• B. Temperature
• C. Longitude
• D. None of them

Explanation: Latitude strongly controls climate because it determines the angle and intensity of incoming sunlight. Temperature is an element of climate, while longitude has comparatively little direct effect.

670. Pomology is the study of: _________?

• A. Mind
• B. Bones
• C. Fruits
• D. Birds

Explanation: Pomology is the branch of horticulture concerned with the cultivation and study of fruit and fruit trees. The word is derived from terms related to fruit.