Describe the main evolutionary trend in digestion across the phyla: Platyhelminthes, Chordata and Annelida

In platyhelminthes digestion is both intracellular and extracellular whereas in annelida and chordata digestion is completely extracellular.

JH

Related Biology A Level answers

All answers ▸

Why is ATP required for skeletal muscle contraction?


When a nerve impulse arrives at a synapse, it causes the release of neurotransmitter from vesicles in the presynaptic knob. Describe how.


Where are the Alpha and Beta cells of the Pancreas located and what are their functions in relation to blood glucose homeostasis?


The pancrease secretes protease enzymes. How do organelles within a cell work together to PRODUCE and RELEASE these protein molecules from the cell?