Biology MCQs

Notes:
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes, bananas, and tamarind. Tartaric acid is used in several food products for its sour taste and antioxidant properties. It has a very sour taste and is a key raw material for making wine, where it plays a vital role in maintaining the color, taste, and texture of the product.

Notes:
Down’s syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.Down’s syndrome is the most common chromosome abnormality in humans. It is typically associated with a delay in cognitive ability (mental retardation, or MR) and physical growth, and a particular set of facial characteristics

Notes:
Nerve cells are affected in Polio. Polio also known as poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis.

Notes:
Calcium is required in plants in the formation of cell wall. It is a structural layer surrounding some types of cells, just outside the cell membrane. The cell wall can be tough, flexible, and sometimes rigid also.

Notes:
Twins are two offspring produced by the same pregnancy. Twins can be either monozygotic (‘identical’), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic (‘fraternal’), meaning that each twin develops from a separate egg and each egg is fertilized by its own sperm cell.

Notes:
When red blood cells are placed in distilled water, the water molecules move into the cells by osmosis because the cells have a higher solute concentration than the distilled water. This influx of water causes the red blood cells to swell and eventually burst in a process known as hemolysis. This demonstrates how osmosis, a vital biological process, can result in cell damage when the external conditions are not balanced.

Notes:
Apart from the temporal bone, femur is considered as strongest bone in human body. It is the only bone located within the human thigh. It is both the longest and the strongest bone in the human body. It extends from the hip to the knee.

Notes:
Genes helps to determine the character of a cell. Gene is the basic physical and functional unit of heredity and are made up of DNA. Some of the genes act as instructions to make molecules called proteins.

Notes:
Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body and therefore it is non-caloric. Sucralose is approximately 600 times as sweet as sucrose (table sugar), twice as sweet as saccharin, and 3 times as sweet as aspartame. It is stable under heat and over a broad range of pH conditions. Therefore, it can be used in baking or in products that require a longer shelf life. The commercial success of sucralose-based products stems from its favorable comparison to other low-calorie sweeteners in terms of taste, stability, and safety. It is used because it is a no-calorie sweetener, and does not promote dental cavities, is safe for consumption by diabetics, and does not affect insulin levels.

Notes:
Rhizobium is a kind of symbiotic bacteria. Many legumes have root nodules that provide a home for symbiotic nitrogen-fixing bacteria called rhizobia. This relationship is particularly common in nitrogen-limited conditions. The Rhizobia convert nitrogen gas from the atmosphere into ammonia.