Tag: biology

Hepatitis is an inflammation of the liver tissue. Symptoms include yellow discolouration of the skin and whites of the eyes, poor appetite, vomiting, tiredness, abdominal pain, or diarrhoea. Hepatitis may be caused by viruses. There are five main types of viral hepatitis - type A, B, C, D, and E.. Hepatitis A and E are mainly spread by contaminated food and water. Hepatitis B is mainly sexually transmitted.  Both hepatitis B and C are commonly spread through infected blood such as may occur during needle sharing by intravenous drug users. Hepatitis D can only infect people already infected with hepatitis B.

Potable water is generally impure and requires treatment before use. It is first purified using sedimentation process which is then followed by chemical coagulation and flocculation which allows grouping particles together into flocs of bigger size. 

Coliform bacteria are microorganisms that primarily found in the intestines of warm-blooded animals and thus, present in animal's faeces. By testing for coliforms, especially the Escherichia coli (E. coli), one can determine if the water has possibly been exposed to faecal contamination; that is, whether it has come in contact with human or animal faeces.

Ascariasis is a disease caused by the parasitic roundworm Ascaris lumbricoides. Ascariasis does not spread directly from person to person. Infection occurs by eating food or drink contaminated with Ascaris eggs from feces. The eggs hatch in the intestines, burrow through the gut wall, and migrate to the lungs via the blood. There they break into the alveoli and pass up the trachea, where they are coughed up and swallowed. The larvae then pass through the stomach for a second time into the intestine where they become adult worms.

Poor people living in slum areas do not have access to clean drinking water or clean surroundings, this can cause infections among them. Education is a very important aspect to avoid causes of diseases. Therefore, (d) is the correct answer.

Several diseases specially diarrhea, gastroenteritis, typhoid, dysentery are very common in areas deficient in proper water supply.
At many places, water from hand -pumps and other sources is contaminated. At certain places, harmful mineral contents in water obtained through wells or
hand pumps cause health problems.

The relationship between oxygen levels and hemoglobin saturation is indicated by the oxygen-hemoglobin dissociation (saturation) curve at high partial pressures of O2 (above about 40 mm Hg), hemoglobin saturation remains rather high (typically about 75 - 80%). This rather flat section of the oxygen-hemoglobin dissociation curve is called the 'plateau'. 40 mm Hg is the typical partial pressure of oxygen in the cells of the body. Examination of the oxygen-hemoglobin dissociation curve reveals that, under resting conditions, only about 20 - 25% of hemoglobin molecules give up oxygen in the systemic capillaries. This is significant (in other words, the 'plateau' is significant) because it means that you have a substantial reserve of oxygen. In other words, if you become more active, & your cells need more oxygen, the blood (hemoglobin molecules) has lots of oxygen to provide When you do become more active, partial pressures of oxygen in your (active) cells may drop well below 40 mm Hg.

Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of the blood through the circulatory system.
Thrombocytes are also called 'platelets' and these are the blood cells, whose function is to stop bleeding.
Thrombin is the enzyme that converts fibrinogen to fibrin, and a reaction that leads to the formation of fibrin clot.
Thrombocytopenia is the disorder in which there is an abnormally low amount of platelets.
Thus, the correct answer is option (A).