Biology MCQs

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:
Vitamin E is a fat soluble vitamin that is essential in many physiological processes. It plays an important role in the health and maintenance of proper reproductive system function. Without vitamin E the body cannot reproduce. It is also essential during pregnancy and is needed for the proper health and development of the fetus.

Notes:
The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis. The mean normal blood glucose level in humans is about 4 mM (4 m mol/L or 72 mg/dL, i.e. milligrams/decilitre); however, this level fluctuates throughout the day.

Notes:
Leaves are the lungs of plants. Much like the lungs of animals, leaves are the place of a plant’s respiration. It is from leaves that oxygen is emitted during the light hours of the day and carbonic acid gas diffuse in during day and released out at night through stomata.

Notes:
In the process of photosynthesis, oxygen is produced from the photolysis of water. The photolysis of water occurs when light is used to renew split water and adenosine triphosphate, also referred to as ATP. The hydrogen remains in the leaf and participates in further reactions. 2H2O(l) = Hydrogen + O2(g)

Notes:
Haptens are small molecules that react with a specific antibody but cannot induce the formation of antibodies unless bound to a carrier protein or other large antigenic molecule. They are incomplete or partial antigens.

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The transport of water, nutrients and other substances from one part of a plant to another is called translocation. While, phloem transports synthesized food from the leaves to the rest of the plant body; water and minerals are transported from the roots upwards through the xylem tubes.

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Palisade parenchyma is the layer of tissue directly beneath the epidermis of the upper surface of a leaf. It contains the cylinder-shaped cells that hold the chloroplasts and constitutes the primary area of photosynthesis that converts the light energy to the chemical potential energy of carbohydrates.

Notes:
Deciduous means “falling off at maturity” or “tending to fall off”, and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe. In a more general sense, deciduous means the dropping of a part that is no longer needed, or falling away after its purpose is finished.

Notes:
The Spinner Dolphin is a vulnerable marine mammal that lives in large offshore schools. The Irrawaddy Dolphin, an endangered euryhaline species, inhabits estuaries, coasts, and rivers. The Bottlenose Dolphin is a common oceanic species found in warm and temperate waters, known for its intelligence. Humpback Dolphins in the Indo-Pacific are classified as vulnerable and reside in coastal waters.