Do bristle worms have direct or indirect development?
Indirect - they have a trochophore larval stage
What kind of circulatory system to arthropods have?
Open!
Contrast simple eyes with compound eyes.
Simple eyes: called occeli, can only detect light vs dark.
Compound eyes: composed of individual structures called ommatidia (hexagonal shaped).
What are the parapodia, and what might be found on them?
Appendages used for swimming and other activities ; and bunches of chetae
What is a cephalothorax?
A body form that has no abdomen - a fused head and thorax
What is the advantage of arthropods having jointed feet?
Allows are better motion with retraction and extension ; joints leverage motion by adding more force
During mating season
Which class hosts the LARGEST group of animals?
Class Hexapoda ; insects
How do spiracles and the tympanal organ benefit insects?
Spiracles: help with respiration and breathing
Tympanic organ: Allows the insect to hear
After pulling off a leech, you realize you lost a good amount of blood, but didn't feel much pain. How does the leech accomplish this?
It secretes vasodilators and anticoagulents to increase blood flow, but also seceretes anesthetics so that the area is numbed to sensation.
You find a long creature with a bunch of legs muching on a leaf. You have time to spare, and sit and count his legs - there are almost 100 legs!! What animal is this?
Millipedes!
Spiders have eight eyes, and lobsters have two. Which one is better at spotting their prey? Why?
Lobsters! They have compound eyes, whilst spiders have simple ones.
Describe the full process of earthworm motion.
Circular musicles contract on the anterior end of the word, thinning the worm and bringing it forward. Chetae lose attachment to the ground on the anterior end to extend the worm. Longitudinal muscles contract to thicken the worm to "bunch" the rest of the worm up and bring it forward.
Name each class of arthropods, and an organism from each one.
Chelicerata: ticks and scorpions
Crustacea: lobsters and barnacles
Hexapoda: Butterflies and beetles
Myriapoda: Centipedes and millipedes
Compare and contrast the mandible and the chelicera. Which classes have them?
Chelicera: only found in Class chelicerate (ticks, spiders). Often called "fangs", with most containing venom to pierce and kill prey
Mandible: Found in class Hexapoda, Myriapoda, and Crustacea. A strong jaw often lined with teeth to crush prey.