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Lab 9 Animal Diversity 2 Quiz Key
1. (1pt) List the names of the 3 main body segments of an insect.
• Head
• Thorax
• Abdomen
2. (1 pt) Parasitic leeches excrete an anesthetic and a substance called hirudin. What
does hirudin do?
Hirudin is a blood thinner.
.
3. (1 pt) What function does the clitellum perform?
A structure called the clitellum secretes a cocoon of mucus that picks up eggs and
then stored sperm during cross fertilization.
4. (1 pt) What type of circulatory system do annelids have?
Annelids have a closed circulatory system.
5. (2 pts) A a small ant can carry an object several times it’s own weight. If an ant
were much larger, would it be able to still carry an object several times it’s own
weight? Explain your answer.
Muscle cross sectional area determines an organisms strength. This is proportional
to the square of the muscle radius. While mass is proportional to the cube of an
objects radius. Therefore a much larger ant would not be able to lift as much relative to its body mass.
6. (1pt) What is the blood like fluid that circulates through the body cavity of an
arthropod called?
The fluid that circulates through the body cavity of an arthropod is called hemolymph.
7. (1 pt) Which arthropods do not have branched appendages?
Uniramians are arthropods that do not have branched appendages. Centipedes
(Chilopoda), Millipedes (Diplopoda), and Hexipoda (Insects and relatives) belong
to this group.
8. (1 pt) How many legs are attached to each body segment of a millipede?
Millipedes have two pairs of legs (4 legs) per segment.
9. (1 pt) Name an organism that has chelicerae. What are chelicarae?
Water scorpions (extinct), sea spiders, horseshoe crabs, and arachnids have chelicerae. Arachnids include scorpions, ticks, mites, and spiders. Chelicerae are claw
like feeding appendages.