General Science Questions (MCQs) for Competitive Examinations

Notes:
Stomata are tiny openings or pores in plant tissue that allow for gas exchange. Stomata allow a plant to take in carbon dioxide, which is needed for photosynthesis. They also help to reduce water loss by closing when conditions are hot or dry. Stomata look like tiny mouths which open and close as they assist in transpiration.

Notes:
The ball and socket joint (or spheroidal joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. One of its example is hip joint, in which a partially spherical end lies in a socket, allowing multidirectional movement and rotation.

Notes:
Polar bears are supremely adapted to their environment – they have a number of traits that help them to cope with snow, ice, and below-freezing temperatures. They have a layer of fat that can be four inches (10 cm) thick. Although their fur is the primary source of insulation, the fat helps keep heat in as well.

Notes:
The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action. Functions of the cerebrum include: initiation of movement, coordination of movement, temperature, touch, vision, hearing, judgment, reasoning, problem solving, emotions, and learning.

Notes:
Black soil is most suitable for the cultivation of cotton. The deep and medium black lava soil of the Deccan and Malwa plateaus is considered ideal, though it can be grown on alluvial and red soil as well. The black cotton soil is also known as regur.

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The plants, which have hard and thick brown stem and are very tall are called trees. The stems have branches in upper part and much above the ground. For example, mango, neem. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants for sunlight.

Notes:
Oviparous is a zoological term that refers to animals that lay eggs which then hatch externally. Oviparous animals may fertilize their eggs either externally or internally. Frogs are oviparous since they lay eggs, which then develop outside of the mother. Ovoviviparous animals are relatively uncommon, sharks are most well-known.

Notes:
Outer Ear or Pinna is found only in terrestrial mammals. It is composed of a thin plate of yellow elastic cartilage, covered with integument, and connected to the surrounding parts by ligaments and muscles.

Notes:
The average heart rate for adult humans is about 70 to 75 beats per minute in a normal relaxed mode. While we tend to think of the “normal” heart beat rate as being “72 beats per minute”, in actuality the heart beat rate is not and could never be constant.

Notes:
Pulses are example of dicots since they have two cotyledons (dicot is short for ‘dicotyledon’, and ‘di’ means two). They contain two seeds inside the seed coat. Legumes (a family of plants that includes pluses, beans, peas and lentils) are all examples of dicot seeds.