Lecture on Flatworms and Reproductive Structures

These flashcards cover key concepts on flatworm anatomy, reproduction, and their life cycles, as discussed in the lecture.

What are the two main types of muscle layers found in flatworms?

Circular and longitudinal muscle layers.

What is the function of pedal waves in flatworms?

To propel the animal forward using a contraction that moves down its body.

What reproductive strategy do most flatworms practice?

Simultaneous hermaphroditism with internal fertilization.

What structures in flatworms allow for regeneration?

Transverse and longitudinal cutting of the body can lead to regeneration of head and tail.

What is hypodermic impregnation in flatworms?

A method where male reproductive structures can insert sperm into the female's body anywhere, often using barbs.

How do flatworm embryos develop differently based on their habitat?

Marine species may hatch as planktonic larvae, while terrestrial ones typically develop directly into flatworms.

What is the significance of the tegument in neodermata?

It is a syncytial outer layer that offers protection and is involved in nutrient absorption.

What are the primary and secondary hosts in the life cycle of trematodes?

Primary hosts are where sexual reproduction occurs, while secondary hosts are where asexual reproduction takes place.

What is a unique characteristic of the Schistosoma blood fluke compared to other trematodes?

They have separate male and female individuals that live together in a groove.

What is the digestive system like in parasitic flatworms?

It is often reduced or simplified, allowing them to absorb nutrients directly across their body surface.