नमस्कार मित्रांनो इयत्ता बारावी Biology या Subject च्या Practical मध्ये PART - B: Demonstration Experiments (Spotting) हा भाग Practical Exam च्या दृष्टीने फार महत्त्वाचा आहे. या Blog Post मध्ये आपण Spotting Practical Number 12: To identify common disease causing organisms like Plasmodium, Entamoeba, Ascaris and Ringworm with the help of permanent slides and or specimens. Comment on symptoms of diseases that they cause. ह्या Practical Experiment चे Answer पाहणार आहोत. खाली दिलेल्या उत्तरांमध्ये काही अडचण असल्यास आम्हाला comment करा किंवा तुमच्या संबंधीत विषय शिक्षकांशी चर्चा करा.
B. DEMONSTRATION EXPERIMENTS (Spotting)
12. To identify common disease causing organisms like Plasmodium, Entamoeba, Ascaris and Ringworm with the help of permanent slides and or specimens. Comment on symptoms of diseases that they cause.
1. Plasmodium (Disease-Malaria) :
1. Plasmodium vivax is an intracellular, blood parasite in humans and other vertebrates which causes malaria.
2. The life history of Plasmodium is completed in two hosts, partly in the definitive host, the man and partly in an intermediate host, the female Anopheles mosquito.
3. When an infected female anopheles mosquito bites a man, sporozoites are introduced in the blood stream from where they reach in liver cells and multiply to form merozoite.
4. After a few cycles in the liver, the merozoite enters the RBC and feeds on the contents of the RBC
5. After 2-8 schizogenous changes in the main blood stream, the merozoite assumes a different shape and is known as a gametocyte.
6. Gametocytes cannot develop further in the blood of humans therefore they wait for female anopheles mosquitoes to suck them with the blood.
7. When the gametocytes are sucked in by the female Anopheles mosquito they further undergo development.
Symptoms:
1. Symptoms of malaria include fever, shivering, caused by release of haemogoin arthralgia (joint pain), vomiting, anaemia (caused by hemolysis), hemoglobinuria, retinal damage and convulsions.
2. The classic symptom of malaria is cyclical occurrence of sudden coldness followed by rigor and then fever, sweating, lasting for four to six hours, occurring at 48 hrs or every two days.
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| Fig. 10.1 : Stages in the life cycle of Plasmodium in mosquito and human |
2. Entamoeba (Disease - Amoebiasis) :
Entamoeba histolytica is a parasite in the large intestine of man. It occurs in three stages:
i) Trophozoite ii) Pre-cystic stage and iii) Cystic stage
1. Disease is caused by the trophozoite form.
2. Cytoplasm is differentiated into ectoplasm and endoplasm
3. Ectoplasm forms pseudopodium.
4. Reproduction by binary fission and encystment.
Symptoms:
1. Entamoeba histolytica causes amoebiasis in man. Trophozoite lives in the mucosa and submucosa layer of the large intestine of man.
2. It causes amoebic dysentery, abscess in the liver, lungs and brain.
3. The common symptoms are the passing out of stool with blood and mucous.
4. Abdominal pains, nausea and bowel irregularity are common symptoms.
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| Fig. 10.2 : Entamoeba histolytica |
3. Ascaris (Disease - Ascariasis) :
Ascaris lumbricoides, also known as the giant intestinal roundworm, is one of the several soil- transmitted nematodes that are infectious to humans.
1. The body is elongated, cylindrical in shape, creamy white or pinkish in colour.
2. Sexes are separate and sexual dimorphism is well marked.
3. Male is about 15-31 cm in length, slender and shows penial setae. The posterior end is curved. The female is about average 20-35 cm in length, the posterior end is blunt and straight.
4. The body is covered with a cuticle.
Symptoms :
1. The disease caused by Ascaris is called ascariasis.
2. The common symptom is vague abdominal pain.
3. In more severe cases, the patient may experience restlessness, weight loss, anorexia, distended abdomen, intermittent loose stool and occasional vomiting.
4. During the pulmonary stage, there may be a brief period of whooping cough, dyspnea and sub-sternal discomfort. Most symptoms are due to the physical presence of the worm.
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| Fig. 10.3 : Ascaris |
4. Ring Worm :
It is caused by different fungi like Trichophyton spp. Microsporum audouinii and Epidermophyton etc.
1. Microsporum audouinii is commonly called a ring worm.
2. The fine mycelium of the fungus occurs in between the breaks in the dermis.
3. It infects hair and feeds on keratin, where hyphae emerge from the sheath and grow up and down.
4. The hyphae in the hair put out to the surface, fine filaments on which spores are born.
5. The spores are very small and are produced in enormous numbers. They are readily detached and spread in infection.
6. Ring worm causes dermotomycosis.
Symptoms of ringworm disease :
1. Red ring patches of vesicles on the skin.
2. Intense itching and scaly skin b sclap.
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| Fig. 10.4 : Ring worm (Microsporum audoinii) |
Sketch diagrams and comments
Questions
1. Which one is the infectious stage of Plasmodium for the human host?
Ans :- The infectious stage of Plasmodium for humans is the sporozoite, which enters the bloodstream through the bite of an infected female Anopheles mosquito.
2. Enlist at least two names of ringworm-causing organisms.
Ans :- i) Trichophyton
ii) Microsporum
3. Give names of any three endoparasitic animals.
Ans :- i) Ascaris lumbricoides (roundworm)
ii) Taenia solium (pork tapeworm)
iii) Fasciola hepatica (liver fluke)
4. What is the difference between pathogen and parasite?
Ans :- A pathogen is a microorganism that causes disease (e.g., bacteria, viruses). A parasite lives on or inside a host, deriving nutrition at the host's expense (e.g., tapeworms).
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