12 Phylum Arthropoda

Question 1

The most species-diverse phylum in the animal kingdom
(3/4th of all known species)
* Utilize all modes of feeding: carnivory, herbivory, omnivory,
and some parasitic
* Most widely distributed in all kinds of habitats, some
surviving in places where no other animal could survive
* Mainly characterized by having segmented bodies, and
having legs and appendages that are jointed
* Bilateral symmetry
* Triploblastic body
* Eucoelomate body cavity
* Level of complexity: Organ-system grade
* Definite cephalization

Answer 1

Phylum ARTHROPODA

Question 2

Segmented body is divided into functional groups called

Answer 2

tagmata

Question 3

(arthron = “ ” + podos = “ ”)

Answer 3

joint, foot

Question 4

The number of tagmatas depends on the subphylum:

Answer 4

Subphylum Myriapoda
Subphylum Hexapoda
Subphylum Crustacea

Question 4

2 tagmatas: Head and Trunk

Answer 4

Subphylum Myriapoda

Question 5

3 tagmatas: Heat, Thorax, and Abdomen

Answer 5

Subphylum Hexapoda

Question 6

2 tagmatas: Cephalothorax (a fusion of head and
thorax) and Abdomen

Answer 6

Subphylum Crustacea

Question 7

– a strong and highly protective covering that is also very flexible

Answer 7

Exoskeleton

Question 8

makes up the hard exoskeleton. It is mainly composed of a protein called chitin and sometimes calcium carbonate

Answer 8

Cuticle

Question 9

– the outer, thin layer that can harder to increase protective capability

Answer 9

Epicuticle

Question 10

the inner, thick layer that is flexible. It is
further divided into 2 layers:

Answer 10

Procuticle

Question 10

(secreted before molting)

Answer 10

Exocuticle

Question 11

(secreted after molting)

Answer 11

Endocuticle

Question 12

the process of shedding of the outer covering at
the cuticular exoskeleton as the arthropod grows.

Answer 12

Molting

Question 13

The process of molting terminates at the actual
shedding of the old exoskeleton (called )

Answer 13

ecdysis

Question 14

After molting, the arthropod has new but soft exoskeleton. In time, it will harden (the process of
hardening is called

Answer 14

schlerotization)

Question 15

abundant inside hollow limbs for rapid movement

Answer 15

Striated

Question 16

found in the organs (like in digestive system.

Answer 16

Smooth

Question 17

– has a long, straw-like proboscis to suck liquid food (ex. Butterfly, mosquito, etc.)

Answer 17

Sucking type

Question 18

– the tip of the proboscis contains grooves that sponges up liquid/semi-liquid food (ex. Housefly, bees, etc.)

Answer 18

Sponging/Lapping type

Question 19

(lays eggs)

Answer 19

oviparous

Question 19

– their mouthparts contain powerful, horizontally cutting mandibles/jaws to cut
solid food (ex. Beetles, grasshopper, spiders, crabs, cockroaches, etc.)

Answer 19

Chewing type

Question 20

(lays eggs inside body and
births larva/young)

Answer 20

ovoviviparous

Question 21

(gives birth directly to
larva/young)

Answer 21

viviparous

Question 22

Many arthropods pass through metamorphic changes, including a larval form that is morphologically
different from the adult

Answer 22

metamorphic changes

Question 23

(the “blood” of
arthropods)

Answer 23

hemolymph

Question 23

– type of excretory and
osmoregulatory system consisting of branching tubules extending from the alimentary canal.

Answer 23

Malpighian tubule system

Question 24

The respiratory system of most insects; it consists of cuticle-lined air tubes
that branches throughout the body and open in tine holes in the abdomen called spiracles.

Answer 24

Tracheal system

Question 25

a series of highly vascular plates (that are arranged like pages of a book) that
serves as respiratory system in arachnids (spiders, scorpions, etc) and crustaceans (crabs,
lobsters, etc.)

Answer 25

book lungs

Question 26

– the “blood” of most arthropods, which is white and fatty

Answer 26

Hemolymph / Hemocoel

Question 27

(not enclosed in vessels and are found throughout the body cavity)

Answer 27

Open circulatory system