Lecture 7-8 - Classifying Animal Parasites

Question 1

Explain why hunter-gatherers have a lower risk of contracting diseases compared to humans after the agricultural revolution.

Answer 1

Hunter gatherers live in a nomadic lifestyle, leaving feces and parasites behind as they move. However, after the revolution, with the self-sustaining food growing and domestication of animals, people start to live in cities. Exposure to improper disposal of sewage as well with animals increases risk of disease transmission.

Question 2

Define zoonoses

Answer 2

Parasites that can jump to similar animal hosts.

Question 3

Describe the characteristics of flatworms (Phylum Platyhelminthes)

Answer 3

• Consist of three cell layers: ectoterm, mesoderm, endoderm
• acoelomate
• simple body structure

Question 4

Mention the two class members of the Phylum Platyhelminthes. Describe them and give an example

Answer 4

Trematode (Flukes):

• Suckers
• Branching gut
• Complex reproductive organs
• Most are hermaphrodites
• Transmitted through snails
• Exp. Fasicola hepatica

Cestode (Tape worms):
Scolex (head) with suckers and hooks
-  Made up of proglottids (segments)
-Transmission through uncooked meat
- Exp. Taenia saginata

Question 5

Describe the characteristics of the Phylum Nematoda.

Answer 5

• Ecdysozoan (Moult outer cuticle)
• 3 body layers
• pseudocoelom
• round body, tapers at both ends
  Exp. Ascaris, filarial worms

Question 6

Describe the characteristics of the Phylum Arthropoda.

Answer 6

• Ecdysozoan (Moult outer cuticle)
• True coelom
• possess outer exoskeleton
• jointed appendages

Question 7

Mention the two classes of Arthropods and differ between them.

Answer 7

Hexapoda (Insects):

• 3 pairs of legs
• 3 body sections: head, thorax, abdomen

Arachnida:

• 4 pairs of legs
• 2 body sections: cephalothorax, abdomen
• no antennae