Week Two: Nematodes an Intruduction (Chapter Three) Flashcards
What are nematodes and what are the three basic types?
Roundworms
- Free living
- Nematodes that parasitize plants
- Nematodes that parasitize domesticated animals, wild animals, and humans
What are the most numerous and diverse group of parasites on earth?
Nematodes
Where are nematodes found in the body?
- GI tract
- Circulatory system
- Respiratory tract
- Urogenital system
- Eye
What are plant nematodes responsible for?
10% loss of cultivated crops
What are some key morphologic features of nematodes?
- Multicellular
- Unsegmented
- Elongate
- Rounded on both ends
- Circular in cross section
- Bilaterally symmetric
What are some external morphologic features of nematodes?
- Covered by a thin cuticle which extends into all body openings (secreted by hypodermis)
- Lateral flattened expansions at anterior end
- Lateral flattened expansion at posterior end
What is the lateral flattened expansions at the anterior end of a nematode called?
Cervical alae
What is the lateral flattened expansion at the posterior end of a nematode called?
Copulatory bursa
What enables nematodes to move?
The somatic muscular layer beneath the hypodermis
What is the pseudocoelom?
Specialized muscles that line the body cavity to aid in feeding and reproduction
Describe the digestive system in a nematode
Explain the difference between male and female as well
Long, straight tube extending from mouth to anus
Females have a rectum
Males have a cloaca
What does dioecious mean?
Separate sexes
Explain the first stage of the life cycle of a nematode
- Female produces egg (single cell stage within egg shell)
- Original cell divides into 2, 4, 8, ect..
- Morula stage
- Tadpole stage
- Developed into a fully formed first stage larava within egg shell
Explain the second stage of the life cycle of a nematode
- Larva emerges from egg shell and molts
2. Develops into second stage larva
What happens between second and third stage of a nematodes (larva) life cycle?
Molts
