Spot No. 7: XII Bio

General Instructions:

  • Copy the given assignment of practical in fair practical copy of biology.
  • Make the use of black pen for heading and sub-headings and blue pen for writing other content.
  • Work should be presentable.
  • Make well labelled and proper diagram as provided in this assignment.

Spot No.7

Aim: To study and identify Ascaris and symptoms of disease caused by it

Materials Required: Museum specimens of Ascaris, Compound microscope

Procedure: 

  1. Observe the museum specimen of Ascaris carefully.
  2. Draw a well labelled diagram of Ascaris observed.

Observations:

Classification

Phylum: Nemathelminthes

Class: Nematoda

Order: Ascaroidea

Genus: Ascaris

Species: lumbricoides

Comments:

  1. Ascaris is endoparasite of man found in small intestine.
  2. It is elongated, cylindrical, wormiform, yellowish or pinkish in colour and tapering at both the ends.
  3. Size.
  1. Male: 15-30cmX3-5mm
  2. Female: 20-40 cmX 6-8 cm
  1. Mouth is triradiated at anterior end and surrounded by 3 lips (1 mid dorsal + 2 ventrolateral).
  2. It possess 4 longitudinal epidermal lines in the entire length of the body (1 dorsal, 1 ventral and 2 lateral lines).
  3. Amphid (chemoreceptor) gustatory helps in feeding.
  4. Possess well marked sexual diamorphism,
  1. Tail is curved ventrally curved in males while straight in females.
  2. Male is smaller than females.
  3. Genital aperture in females is at mid ventral from anterior end.
  4. Penial spicule, cloaca, pre-anal and post-anal papillae are present in male but absent in female.
  1. Life span of Ascaris is 9-12 montghs
  2. It causes Ascariasis disease.

Mode of infection

  1. Food and water contaminated with embryonated eggs
  2. Second stage rhabditiform larva is infective stage of parasite.

Symptoms of Ascariasis

  1. Loss of appetite
  2. Insomnia
  3. Colic pain
  4. Abdominal discomfort
  5. Irregular bowel movement
  6. Occasional vomiting
  7. Anaemia

Prrecautions:

  1. Handle the museum Specimen carefully.