Bio Chp 27 Warm up 3
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Bio Chp 27 Warm up 3
Bio Chp 27
Never had it so GOOD :)
What is a meeting evolutionary innovation that occurred among cnidarians?
Extracellular digestion of food
What happens when food is trapped by a sponge chaonocyte?
it is directly taken to endocytosis and digested intracellularly.
Where in cnidarian's is food digested?
Extracellularly in a digestive cavity
What has been retained by all of the more advanced groups of animals?
Extracellular digestion of food.
What are a cnidarian's two basic body forms?
Medusae & Polyps
Describe the characteristics of a medusae?
Free-floating, gelatinous, contains lots of mesoglea, the mouth and tentacles face downward, and umbrella shaped
Describe the characteristics of polyps.
they are cylindrical, pipe shaped, have a little mesoglea, the mouth and tentacles face upwards
What does bilaterally symmetric mean?
Animals have left and right halves that mirror each other.
Name the 4 parts of a bilaterally symmetric animal?
Describe them Dorsal- top surface of animal, Ventral- bottom surface, Anterior- front end, Posterior-back end
Bilateral symmetry a major evolutionary advancement among animals?
It enables different parts of the body to become specialized different ways
What is cephalization?
The evolution of a head end
Animals with heads are often ______?______ and ______?______.
Active and mobile
They move through their environment headfirst with sensory organs concentrated in front so the animals can sense what?
Food, danger, and potential mates
What are the simplest of all the bilaterally to symmetric animals?
How many species of the flatworms exist?
Flatworms are the ___________ animals that have organs
What is an organ?
A collection of different tissues that work together as a unit to perform a particular function
Describe a flatworm
Soft body to animals that are flattened from dorsal-ventrally
What are flatworms sense organs called?
What can eyespots do?
Detect light but cannot focus
What is a flat worms digestive tube or gut surrounded by?
Tissues or organs
What are the organs?
Testes and ovaries
Why are flatworms called solid bodied worms?
They have no body cavity between their digestive track and skin
What is the solid-body construction called?
Acoelomate meaning "without" "body captivity"
Why must flatworms be thin?
Because of their acoelomate body design
Flatworms have no circulatory system so what and what can pass through the solid body by diffusion?
Oxygen and carbon dioxide
What is an advantage of a thin body of a flatworm?
Shortens distant that the gases must travel to reach each cell.
What is the only opening to the gut?
What enters and exits the mouth of a flatworm?
Food enters ; waste exits
Some flatworms are ____________ but many are ____________.
Free-living ; parasites
What is the magor advancement in fatworms?