Important Points to Remember

• Vitelline glands or yolk glands secrete yolk cells.
• Fasciola is harmless to snail but it is pathogenic in vertebrate hosts including man. It causes “liver rot”.
• Cysticercosis is caused by incidental ingestion of onchospheres. These may settle in eye causing blindness, in case in brain, causes necrosis which may result in epilepsy, paralysis or death.
• Syncytial means when cell boundaries are not demarcated by cell membrane. Several nuclei live in the cytoplasm.
• Stomadaeum is anterior part of alimentary canal lined with epidermis.
• Proctodaeum is the last part of alimentary canal & is lined with epidermis.
• Fasciola gigantica is liver fluke of cattle.
• Fasciolopis (Fasciola buski) is a fluke that lives in human stomach & duodenum. It causes liver rot.
• The term heterogamy is used when larval forms reproduce asexually by parthenogenesis.
• Therapy means treatment of diseases.
• Prophylaxis means, prevention of infection of the disease by germs.
• Planaria has lateral polarity. If head is cut longitudinally into two or several parts along middle line, each part grows into a complete head thus forming a several headed planaria. This is heteromorphosis.
• Laurer’s canal is a muscular copulatory organ which serves as vagina during copulation.
• Mehlis glands or shell glands do not play any role in shell formation. Their secretion helps to lubricate the uterus for the smooth passage of eggs.

  Fig. A flame cell Fig. Echinococcus granulosus : Dog tapeworm

Further Reading :

1. Protozoa

2. Plasmodium

3. Polychaeta

4. Oligochaeta