Biology MCQs

Notes:
White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells.

Notes:
Biotin also called vitamin H, vitamin B₇ or vitamin B₈ is a water-soluble B vitamin. It is also known as vitamin H. Biotin is not a used in the Digestion of food.

Notes:
The formation of Urea takes place in Liver. Urea which is also known as carbamide, is a waste product of many living organisms. It is the major organic component of human urine.

Notes:
Blood Pressure is expressed in two numbers. The higher number is known as Systolic Pressure, or the amount of force (as measured in millimetres of mercury) that is exerted against the artery walls during a heartbeat (contraction). The lower number in the Diastolic pressure, which does the force exist while the heart is resting between beats.

Notes:
Hyponatremia is a low sodium level in the blood. Mild symptoms include a decreased ability to think, headaches, nausea, and poor balance. Hypernatremia is an electrolyte imbalance under which we find high level of sodium in the blood.

Notes:
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of almost all vertebrates as well as the tissues of some invertebrates. Haemoglobin in the blood carries oxygen from the lungs or gills to the rest of the body.

Notes:
The five kingdom classification was proposed by R.H. Whittaker in 1969. The five kingdoms were formed on the basis of characteristics. It includes Kingdom Monera, Kingdom Protista, Kingdom Fungi, Kingdom Plantae, and Kingdom Animalia.

Notes:
Oxygen is a natural element which no animal can live without. Fish and other aquatic animals depend on oxygen gas dissolved in water as much as people depend on oxygen gas in air. Many people are surprised to learn that fish and other aquatic organisms don’t use oxygen from water molecules (H2O). This is because the single oxygen molecule (O) is bound to the two hydrogen molecules (H2) and is not useable in this form. Instead, aquatic organisms depend on dissolved oxygen gas (O2), a colorless, tasteless and odorless substance that enters the water from plants and the atmosphere.

Notes:
The hypothalamus part of the brain works with other parts of the body’s temperature-regulating system, such as the skin, sweat glands and blood vessels. Water evaporating from the skin cools the body, keeping its temperature in a healthy range.

Notes:
Mitochondrial DNA is the small circular chromosome found inside mitochondria. The mitochondria, and thus mitochondrial DNA, are passed almost exclusively from mother to offspring through the egg cell. Electron microscopy reveals mitochondrial DNA in discrete foci.