General characteristics of Arthropods Flashcards
1
Q
General charactersitics
A
- Exoskeleton
- Bilateral symmetry
- Specilization
- Open circulatory system
- Respiration by spiracles+trachea, or gills
- Brain and ventral nerve cord
- Complete digestive system
- Excretory system
2
Q
Functions of exoskeleton
A
- Support body & maintain form
- Provide surface for muscle attachment
- Sclerotized regions provide structural rigidity while membranous regions permit movement and flexibility
- Contains color pigments and patterns important for defense, courtship, intraspecific recognition, and thermoregulation
2
Q
Types of colour pigments
A
- Pigmental: Derived from plants or from pigment deposition
- Structural: Derived from cuticle and its irregularities
2
Q
Structure of exoskeleton
A
- Cuticle: Secreted by epidermis, acellular, multilayered.
- Epidermis: Cellular layer that secretes the cuticle & forms external sensory receptors
- Basement membrane: Acellular, thin, separates hemocoel from epidermis
3
Q
Cuticle
A
- Epicuticle: Protection and impermeability (contain wax layer)
- Procuticle: Procuticle further differentiates into exocuticle (sclerotized) and endocuticle (soft)
3
Q
Bilateral symmetry
A
Body divided into 20 primitive segments or metameres & grouped into 3 distinct tagmata:
* Head: 6-segmented
* Thorax: 3-segmented
* Abdomen: 11-segmented
4
Q
Tagmosis
A
The organization of the body into major units
5
Q
Specialization
A
- Head: Sensory & feeding
- Thorax: Locomotion
- Abdomen: Reproduction
- Jointed appendages: Modified into numerous specialized organs
6
Q
Molting
Definition
A
Process of preparing for, undergoing, and recovering from ecdysis.
7
Q
Ecdysis
A
Process of shedding the old cuticle
8
Q
Ecdysone
A
Hormone to activate epidermal cells to secrete new exoskeleton.
9
Q
Exuvia
A
Old cuticle
10
Q
Apolysis
A
Separation of the old cuticle from the epidermis.
11
Q
Teneral
A
A soft, newly emerged insect
12
Q
Tanning or sclerotization
A
Stiffening and darkening of the cuticle
