Tag: science & technology

The normal resting pulse rate for adults is 60-100 beats per minute. This is the standard medical reference range for healthy adults at rest. Options A and B are incorrect ranges, while D is too narrow.

French physicists Charles Fabry and Henri Buisson discovered the ozone layer in 1913 through spectroscopic methods. They observed that certain wavelengths of solar radiation were absorbed by atmospheric ozone, identifying this protective layer in the stratosphere.

Ozone is an allotrope of oxygen consisting of three oxygen atoms (O3). Unlike the more common diatomic oxygen (O2) we breathe, ozone is a powerful oxidizing agent found primarily in the stratosphere where it forms the protective ozone layer.

CFCs (chlorofluorocarbons) were widely used as refrigerants in refrigerators and air conditioning systems before their ozone-depleting effects were discovered. They were also used in aerosol sprays, but refrigeration was a major application.

The primary greenhouse gases are carbon dioxide (CO2), water vapor (H2O), nitrous oxide (N2O), and methane (CH4). These gases trap heat in Earth's atmosphere through the greenhouse effect. Options A, B, and D contain incorrect chemical formulas or non-greenhouse gases.

By 2009, after CFCs had been largely phased out due to the Montreal Protocol, nitrous oxide became the largest ozone-depleting substance emitted by human activities. N2O is both a potent greenhouse gas and contributes to stratospheric ozone destruction.

Andrologists are medical specialists who diagnose and treat disorders of the male reproductive system. This includes conditions affecting male fertility, sexual dysfunction, hormonal imbalances, and structural abnormalities. The term 'andrology' is derived from 'andro' (male) and 'logy' (study of), making it the male counterpart to gynecology (female reproductive medicine).

Dermatologists are medical doctors who specialize in diagnosing and treating conditions of the skin, hair, nails, and mucous membranes. They study skin structure, functions, and diseases ranging from acne and eczema to skin cancer. Dermatology encompasses both medical and surgical aspects, requiring knowledge of the skin's complex role as the body's largest organ and first line of defense.

Hematologists are medical specialists who study blood and blood-forming tissues, including bone marrow. They diagnose and treat blood disorders such as anemia, leukemia, lymphoma, clotting disorders, and other conditions affecting blood cells. Hematology requires understanding of blood components (red cells, white cells, platelets, plasma) and their functions in oxygen transport, immune response, and clotting.

Hepatologists are medical specialists who focus on diseases of the liver, gallbladder, biliary tree, and pancreas. They study conditions such as hepatitis, cirrhosis, fatty liver disease, and liver cancer. The liver's vital roles in detoxification, metabolism, and protein synthesis make hepatology an important field. Note that 'dieases' in the question is a typo for 'diseases'.