Biology Class 12 Lab Experiments

Comment on symptoms of diseases cause by Common disease causing organisms

Common disease causing organisms like Ascaris, Entamoeba, Plasmodium, any fungus causing ringworm through permanent slides, models or virtual images or specimens. Comment on symptoms of diseases that they cause

Aim: Common disease-causing organisms like Ascaris, Entamoeba, Plasmodium, any fungus causing ringworm through permanent slides, models or virtual images or specimens. Comment on symptoms of diseases that they cause

Material/Apparatus Required:

Preserved slides or specimens of disease-causing organisms like Ascaris, Entamoeba, Plasmodium and Ringworm

Procedure

Observe the specimens or slides and identify the organism on the basis of its features.

Observation:

A. Ascaris

Phylum: Aschelminthes

Class: Nematoda

Type: Ascaris lumbricoides

Ascaris exhibits the following characteristic features:

1. It has a long, cylindrical and unsegmented body.
2. The male and female organisms are separate.
3. It bears a mouth at the anterior end surrounded by three lips.
4. There is an excretory pore on the ventral surface slightly behind the anterior end.
5. A pair of penial spicules are present in the male worms close to the cloacal opening.
6. The female genitals are present at about one-third distance from the anterior end.

Ascariasis is the disease caused by Ascaris lumbricoides or roundworm.

Symptoms:

• Abdominal cramping
• Abdominal swelling
• Nausea
• Vomiting
• Fever

B. Entamoeba

Phylum: Protozoa

Class: Rhizopoda

Type: Entamoeba hystolytica

Following are the characteristic features of Entamoeba:

1. It is a unicellular organism with an irregular shape.
2. It consists of a few food vacuoles. The contractile vacuole is absent.
3. Cysts with four nuclei are present.
4. It consists of a nucleus located eccentrically in the cell.

Entamoeba histolytica is an organism found in the intestines of humans that is responsible for causing amoebic dysentery

Symptoms:

• Abdominal pain
• Watery diarrhoea with mucus, blood and pus
• Fatigue
• Fever
• Nausea
• Vomiting

C. Plasmodium

Phylum: Protozoa

Class: Sporozoa

Type: Plasmodium vivax

Plasmodium can be identified by the following characteristic features:

1. It is a unicellular endoparasite found within the red blood cells of the diseased person.
2. The parasite is mostly diagnosed at the "signet ring" stage where the parasite appears as a round body.
3. There is a big vacuole present inside the cell. The cytoplasm is accumulated at one place and contains the nucleus. Plasmodium vivax is a protozoan parasite that causes malaria in humans. The infected female anopheles bites a healthy person and transmits the sporozoite into the peripheral blood vessels of humans, thereby, causing malaria.

Symptoms:

• High fever
• Shaking chills from moderate to severe.
• Headache
• Vomiting
• Nausea

D. Ringworm

Kingdom: Fungi

Class: Deuteromycetes

Type: Trichophyton rubrum

Trichophyton or ringworm fungus has the following characteristic features:

1. This fungus feeds on the keratin of the skin of human beings.
2. The hyphae are waxy and can be smooth or cotton-like.
3. Hyphae that are not stained are yellowish-brown, reddish-brown or white in colour.

Ringworm is a communicable fungal infection of the skin.

Symptoms:

• Scaly, itchy skin
• Red and raised patches
• They are redder at the periphery than at the center and forms a ring-like appearance

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