EEMB 3: Animals - Arthropods Flashcards
What group of animals dominate the animal kingdom? Why?
AthropodsThey are the most successful and the most diverse
Athropods branch from what linage of animals?
Ecdysozoans
What is the key characteristic of arthropods?
the epidermis is made of a chitinous exoskeleton
Jointed appendages first appear in ___. What era?
trilobitesPaleozoic Era
What is the event that wiped out almost 90% of the species on earth?
Great Permian Extinction
3 key characteristics of arthropods
rigid exoskeletonsegmentationjointed appendages
Why are joined appendages so great?
they can be modified for different functions(specialization)
The major theme in arthropod evolution
specialization
The exoskeleton is ____ layered, made of ____ which is a polysaccaride
multi-layeredchitin
Jointed appendages are moved by ______
muscles attached to the rigid surface
Attributes of the exoskeleton that led to its large impact
Support on dry land (allowed to move to terrestrial environments)Waterproof
What is the scientific word for molting?
Ecdysis
Molting is under the control of ____ which is produced by what organ?
hormonesY-organ
The hormone that causes ecdysis is called
ecdysteroid
Two ways the old cuticle is disposed of
partially digested by enzymesbody swells and breaks out
Muscles in arthropods are smooth or striated?
striated
Arthropods have and open or close circulatory system?
open (heart)
What is diagnostic of arthropods in terms of the circulatory system?
the “heart with ostia”
What cell type carries oxygen in the blood of arthropods?
Hemocyanin
Gas exchange in arthropods happen through ___. Which type is the one exception and what does it use instead?
tracheaspiders- book lungs
The 4 major groups of arthropods
CrustaceaHexapoda (Insecta)MyriapodaChelicerata (Arachnids)
Which group is the most dominant marine arthropod?
Crustacea(Decapods, isopods, amphipods, cepepods, barnacles)
Crustaceans are divided into what 3 parts
headthoraxabdomen
What structure covers the head and thorax of the crustaceans
the carapace
Crustaceans have _____ larvae
naupilus
T/F: crustaceans don’t have chromatophores
False!
What may be the most abundant animal on the planet?
Copepods (zooplankton)
Where does “marine snow” come from?
poop of copepods
Most successful isopods?
Rolly pollies (sow/pill bug)
Barnacles are _______ and have a very large _____
hermaphrodtic long penis
First animals to develop flight
hexapods
Hexapods have 3 pairs of _____ on the _____
appendagesthorax
Trachea maximizses _____ over which respiratory gas exchange and occur
body surface area
What are the openings on the surface on insects for respiration
spiracles
Insects equivalent of human kidneys (nephron tubes)
Malpighian tubules
How is the development in wingless insects
Babies look like mini adults
What are instars?
the molten shell of insects (just that the insect needs to molt a lot to develop)
Pterygote insects are what type of bugs?
winged insects
The development of Pterygote insects involve the ___ and adult stage
larval
Three groups of Pterygotes involve
ones that cannot hid wingsones that can but don’t go through complete metamorphasisones that can hide wings and do complete metamorphasis
The only insect that cannot fold its wings (common and scientific names)
dragonflies/damselflies (predators-aquatic larvae) Odontata
Most winged insects fall under which category of Pterygotes?
Ones that fold wings and undergo complete metamorphosis
Examples of the group Chelicerates
spiders, scropions, mites, horeshoe crabs, “sea spiders”
Distinct body regions for chelicerates
abdomen and cephalothorax
At the anterior of the cephalothorax, there are mouth parts called. They lack ____
cheliceraemandibles
Sea spiders fall under class
Pycnogonida
Describe sea spiders
small bodies with long legs, complete digestive system with a sucker for a mouth
In spiders, chelicerae are modified into ___ that have ___. Therefore all spiders are
fangspoison glandspredators
How do spiders make webs?
silk glands
How are spiders better at detecting motion?
They have simple eyes
The horseshoe crabs fall under what group chelicerates. What significance do they have?
MerstomataUsed for medical purposes for bacterial infections
What is different about the body plan of Myriapods
only two parts(head and trunk)
Myriapods have which two groups of arthropods?
Centipedes (carnivores) - 1 pair of legs per segmentMilipedes (scavegers/herbivores) - 2 pairs of legs per segment
Wings most likely evolved from ____
gills
How are wings ecologically successful?
escape, distribution, new frontiers
