Biology MCQs

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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.

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Cell division is the process by which cells produce new cells. In animals some tissues must be repaired often such as the lining of gut, white blood cells, skin cells with a short lifespan. Other cells do not divide at all after birth are neurons.

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Heart rate is the speed of the heartbeat measured by the number of contractions of the heart per minute (bpm). Conventionally, a normal adult has a heartbeat rate of 72 per minute. However, the heart rate can vary according to the body’s physical needs, including the need to absorb oxygen and excrete carbon dioxide.

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Time required for the organism to eliminate 50 per cent of the total body burden or tissue concentration of chemical is referred to as Half Life Period. A biological half-life or elimination half-life is the time it takes for a substance (drug, radioactive nuclide, or other) to lose one-half of its pharmacologic, physiologic, or radiological activity.

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With its excess secretion, also known as hypersecretion, thyroxine (T4) causes an increased heart rate, high blood pressure, possible palpitations, and could lead to heart failure. It is related to hyperthyroidism.

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In citrus fruits such as oranges, the nucleus cells that surround the embryo start dividing and protrude into the embryo sac. These develop into embryos; thus resulting in the presence of more than one embryo inside each ovule. This condition is known as polyembryony.

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The ‘unicellular organisms’ are single-celled organisms, wherein various functions like feeding, locomotion, expelling wastes, reproduction, etc. are carried out by the single cell. Some examples include organisms such as amoeba, euglena, paramecium, bacteria, and cyanobacteria. Hence, all options are correct as they all represent examples of unicellular organisms.

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Oxytocin is a hormone that is normally produced in the hypothalamus and stored in the posterior pituitary gland. It plays a role in social bonding, sexual reproduction in both sexes, and during and after childbirth. It’s released causes stretching of the cervix and uterus during labor and with stimulation of the nipples for breast feeding.

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Plant tissue culture is a collection of techniques used to grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation. Plant tissue culture relies on the fact that many plant cells have the ability to regenerate a whole plant (totipotency). The culture medium contains a gel (agar) with the proper mixture of nutrients, sugars, vitamins and hormones, necessary for rapid rates of produce new plantlets.

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The cerebellum controls the equilibrium aspects of balance, and muscle tone, which are factors that provide for smooth movement and activity. Electrical impulses from the cerebellum stimulate skeletal muscles that are responsible for voluntary movement, and it works in coordination with the motor cortices of the cerebrum for the overall function.