intro to arthropoda

Question 1

What are phylum arthropoda’s defining characteristics?

Answer 1

• a hard, chitinous exoskeleton
• lack of cilia

Question 2

describe arthropodas chitinous exoskeleton

Answer 2

• made of chitin
• it is a hardened, jointed cuticle
• functions as a skeleton, for protection and for locomotion

Question 3

what is the haemocoel?

Answer 3

• the ‘functional’ second coelom in arthropods
• a blood cavity that can act as a water reservoir, hydrostatic skeleton, and open circulatory system

Question 4

What is tagmatization?

Answer 4

the fusion and specialization of each segment for unique functions

ex. head, for sensing environment, feeding, et
abdomen, for storing organs

Question 5

What is metamerism?

Answer 5

repeated organ systems in each segment

Question 6

what is ecdysis?

Answer 6

• the process of shedding non-living cuticle for the function of growth and development

Question 7

striated muscles in arthropods allow for

Answer 7

fast locomotion and movement

Question 8

What is sclerotization?

Answer 8

hardening of cuticle after ecdysis

Question 9

arthopods have what kind of circulatory system?

Answer 9

• open circulatory system
• means that blood is not always contained within vascular tissue

Question 10

compound eyes have collections of subunits called….

Answer 10

ommatidium

Question 11

What are ommatidium?

Answer 11

• collection of subunits within compound eyes
• contain lens, pigment cells, and light sensitive portion

Question 12

What is the difference between apposition vs. superposition eyes?

Answer 12

Apposition: Photopic eye, typical compound eye where pigment cells are opaque

superposition: scotopic eye, pigment migrates and pigment cells become transparent. Images overlap over each other results in blurry image