Compare and contrast the three phyla of worms. Which is considered to be the most evolutionarily advanced?
· Platyhelminthes are the flatworms. They are the simplest kind of worm. Some are parasitic, but most are free-living predators and scavengers. Flatworms are the first organism to have a primitive central nervous system. They also have small eyespots instead of a complex eye. Flatworms exchange gases through its skin because it lacks a true respiratory or excretory system.
· Nematodes are roundworms. They are the first worm to develop a digestive system. These worms are considered the most successful due to their representation in a variety of environments. They are especially successful in sediments. Most of these worms are free-living and microscopic.
· Annelids are segmented worms with a number of divisions. It allows for growth in the worm to occur in evenly spaced segments. Each segment contains its own circulatory, excretory, nervous, muscular, and reproductive system.
· Annelids are considered to be the most evolutionarily advanced worm.
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Life has been sustained on the earth
A. for approximately six billion years. B. since the time of the last impact of the meteorite. C. through millions of years of ice ages and long warming periods. D. since the human species has been around. E. because of renewable resources.
Which of the following terms refers to the friction of fluid flow?
A. compression B. viscosity C. convergence D. shear
The lowest infant mortality rate in Central Asia is found in:
A) Afghanistan B) Turkmenistan C) Uzbekistan D) Kazakhstan
Coral bleaching refers to
A) the process whereby coral change color to avoid detection by predators. B) the loss of algae from the coral. C) the killing of coral formations by chlorine bleach pollution. D) the replacement of normal, colored algae by white algae.