Review Sheet -- Test 1 (Week 2)         Biology 1224 -- Entomology; James Adams

Basic Biological Concepts:
    Life:
        Cells -- with a cell membrane
        DNA -- genes
        Metabolism -- all the chemical reactions in the body that keep the body alive
                Requires nutrients (carbohydrates, proteins, lipids) for:
            Growth
            Cellular Respiration -- captures energy in ATP
    Evolution -- Change in genetic frequencies in populations through time
            Natural Selection
    Ecology -- all the interactions with living and non-living things in the environment
            The relationships an organism has with everything around it that make up the role that
                    organism plays in the "circle of life"

External Anatomy of Insects -- The Insect Body (Chapter 2)
        See "Entomological Terms" handout
Directional Terms (page 20)
Exoskeleton -- with Cuticle
        Sclerites -- on tergum, pleuron, sternum
        Setae (hairs)
        Spines and spurs
        Muscle Attachments
        Sutures
Segments -- the basic body ground plan (page 23)
    Appendages early on in the evolutionary history of arthropods, with at least one pair on many
        segments (including antennae/mouthparts in head); neural function concentrated forward
    For hexapods (insects), locomotion (legs/wings) ultimately concentrated in thorax

Head -- total number of segments debatable (page 23)
        Prostomium
        One segment for antennae, likely another behind that (crustaceans have two pair ant.)
        One segment each for mandible, maxillae, and labium
    Eyes -- compound with ommatidia, ocelli
    Head regions
    Antennae -- scape, pedicel, flagellum
    Mouthparts -- mandibles, maxillae, labium

Thorax -- three segments: pro-, meso- and metathorax (page 35)
    Larger sclerites often subdivided into distinct smaller sclerites by sutures
    Notum = tergum in thorax
        Each notum has an anterior part (scutum) and a posterior part (scutellum)
    Pleurites -- with basal wing and leg (meron) processes (connections)
        divided into anterior episternum and posterior epimeron
    Sternites

    Legs: fore-, mid- and hindlegs
        meron, coxa, trochanter, femur, tibia, tarsus, pretarsus
    Wings: Veins and regions (See "Entomological Terms" handout)

Abdomen: usually 10 - 11 segments, but proturans add on with molts, springtails have 6. (page 43)
    No appendages (appendages gone), though some groups have cerci.
    External reproductive organs associated with segments 8 & 9 in most
        Aedeagus (male) and ovipositor (female)

The Integument -- also called the exoskeleton (Chapter 3, pages 51 - 56)
        Cuticle (with Epicuticle and Procuticle) with underlying cellular epidermis.
    Cuticle -- has pigments (such as the dark melanin) in it that give it its color
        Must be molted to grow -- process of molting called ecdysis
       
The epicuticle has several components, including a very tough (cement) outer layer, and a
            waxy (waterproof) layer
        The procuticle is softer, flexible and rich in both proteins and the carbohydrate chitin; the
            protein molecules are cross-linked (stuck together or "tanned") during the
            sclerotization (hardening) process of the exocuticle portion after molting; the chitin is
            further attached to the proteins to further strengthen and also maintain some flexibility
            of the sclerites.  At junctions between sclerites, however, no sclerotization occurs; only
            chitin-rich endocuticle is found at the joints between sclerites, giving the insect the
            flexibility at the joints it needs to move.
    Epidermis -- responsible for secreting the new cuticle after molting.
        As the new cuticle is laid down (initially under the old cuticle), the epicuticle is laid down
            first, followed by the procuticle.  Some of the old procuticle is digested and reutilized in the
            construction of the new procuticle (this also helps loosen the old procuticle so that it can
            be shed).  The epicuticle, however, is not hardened until after the old cuticle has been shed,
            and this is done by adding tanning (sclerotizing) agents to the epicuticle after the insect has
            expanded its body.  This means that there must be minute passageways (pore canals) from
            the epidermis to the surface for the tanning materials to get to the epicuticle.