Lab 10 Arthropoda, Nematoda, Tardigrades

Question 1

Nematoda: what are the characteristics? How do they move/compare to annelids? Why? Are they free living or parasitic? How do they grow? Difference between male and female?

Answer 1

• round body non segmented
• they wiggle since they only have 1 muscle, annelids have 2 muscles so controlled movement
• parasitic: causes elephantiasis
• they molt 3 times
• males have a curly tail, females have a straight tail

Question 2

Tardigrada: where do you find these organisms? What are the characteristics?

Answer 2

• marine sands and on water films of plants

- they have fleshy unjointed legs

Question 3

What traits are unique to the phylum Arthropoda?

Answer 3

• jointed appendages
• exoskeleton (not a shell)
• molt: sheds outer skin to grow
• tagmata: specialized body

Question 4

Tagmata

Answer 4

Specialized body regions to perform specific functions

Question 5

Chleicerata: what type of mouthparts do these organisms have? Are they used for grasping or chewing?

Answer 5

-chelicerae: used for grasping not chewing

Question 6

Class: xiphosura

Answer 6

-horseshoe crabs

Question 7

Class: arachnida: how many legs do they have? How many antennae do they have? How many tagmata do they have? What are they called?

Answer 7

• 8 legs
• no antennae
• 2 tagmata: cephalothorax and abdomen (reproduction)

Question 8

Mandibles vs chelicerae

Answer 8

Mandibles can chew

Question 9

Centipedes: how many legs per segment? Is the trunk flat or round? Are they hunters or detritivores? Are they venomous?

Answer 9

• subphylum: myripoda
• one pair of legs per segment
• flat body
• hunters
• all are venomous

Question 10

Millipedes

Answer 10

• subphylum: diplopoda
• round body
• 2 pairs of legs per segment
• dertitivores
• secrete noxious chemical from segments it venomous

Question 11

What structures tell you a barnacle is an arthropod and not a mollusk?

Answer 11

-barnacles have an exoskeleton and jointed appendages

Question 12

Difference between a male and female crayfish?

Answer 12

-females have soft and feathery swimmerets and males have hard and long swimmerets

Question 13

Structure in a crayfish stomach that aids in digestion

Answer 13

Gastric teeth/Gastric mill

Question 14

What type of circulation do crustaceans have?

Answer 14

• open circulation

- their heart has a hole (Ostia)