Endoskeletons of skates, rays, and sharks are made up mostly of:

Many Annelids have complex movement patterns using circular and longitudinal muscles. How is it that these musclęs, which need to contract against a rigid structure, is able to work for annelids which are soft bodied? O most annelids have a soft shell O most annelids have an endoskeleton O most annelids use a rigid cuticle O most annelids use a rigid bristles O most annelids use a rigid hydrostatic skeleton MacBook Pro 8.

Which group of animals have endoskeletons? Annelids and Mollusca O Cnidaria and Ctenophora Nematoda and Arthropoda O Echinodermata & Chordata

Describe the exoskeleton and examples of organisms with this type of skeleton Which is the main component of the exoskeleton of arthropods?

How are mammalian gaits related to the molecular structure of muscle?

Crayfish, unlike earthworms, do not have a hydrostatic skeleton. Instead, crayfish have a rigid exoskeleton. Give 2 advantages to the having the exoskeleton and 2 disadvantages.

What disadvantages associated with having exoskeletons did arthropods have to overcome to allow natural selection to favor this trait? How did they circumvent these problems?

1a. Aquatic ...…...……… go to 2 1b. Not aquatic ….....…….. go to 3 2a. Has gills ...…………. go to 4 2b. Does not have gills ..…..go to 5 3a. Walks on four legs .... go to 6 3b. Walks on two legs ....... go to 7 4a. Has a large, opaque, dorsal fin ....shark 4b. Does not have a large, opaque, dorsal fin …………………….....goldfish 5a. Has a solid colouration ...…..dolphin 5b. It distinctly patterned in white and black …… ...………………… killer whale 6a. Has hooves ...………. go to 8 6b. Does not have hooves ... …dog 7a. Has feathers ...………. ostrich 7b. Does not have feathers ... human 8a. Has horns ...…………… cow 8b. Has antlers (branching) ... ……………moose Which steps would you take in the dichotomous key above to classify the following organism:   Question 17 options:   1a, 2b, 5a   1b, 3b, 7a   1b, 3b, 7b   1a, 2a, 5a   1a, 2a, 4b

Contrast the structure's and or systems used by Leuconoid sponges, snails and earthworms to circulate materials throughout the body. In addition to describing the structure of the system also comment on the relative efficiencu of each system for the lifestyle of each organism

How do animals become multicellular organisms? Structural organization of animals? What structural protein is prevalent in animals?