Bio Ch 28

Front 1

Sessile

Back 1

firmly attatched to a surface

Front 2

cleavage

Back 2

series of mitotic cell divisions

Front 3

blastula

Back 3

hollow ball of cells

Front 4

gastrulation

Back 4

process of forming and segregating layers of tissue (germ layers)

Front 5

larva & metamorphosis

Back 5

a sexually immature form that may look very diffrent from the adult. Which goes thru metmrphss and becomes into a juvenile form

Front 6

2 classifications of animals

Back 6

Parazoa & Eumetazoa

Parazoa- no tru tissues. (sponges)

Front 7

Symmetry

Back 7

arrangement of body structures in relation to the body axis.

Radial or bilateral

Front 8

Radial symmetry

Back 8

body has the general form of a wheel or cylinder. Multiple planes can be drawn.

Front 9

Bilateral symmetry

Back 9

can be divided thru only one plane (midline).

Lead to evolutionary trend od cephalization

Front 10

Cephalization

Back 10

development of a head

Front 11

Diploblastic

Back 11

2 tissue layers.

Front 12

Ectoderm

Back 12

skin and the Nervous tissue

Front 13

Endoderm

Back 13

forms lining of digestive tube

Front 14

Triploblastic

Back 14

have three layers

Front 15

mesoderm

Back 15

muscles, skeletal structures, circulatory system.

Front 16

coelom

Back 16

body cavity in triploblastics. Fluid-filled space between the body wall & the digestive tube. hydrostatic skeleton

Front 17

blind-sac body plan

Back 17

single opening for mouth and anus.

Front 18

tube w/in a tube body plan (true coelom)

Back 18

the body wall, forms outer tube, is from ectoderm. tissues from endoderm lines the inner digestive tube.

Front 19

pseudocoelom

Back 19

"false coelom". occurs between endoderm and mesoderm.

Front 20

developmental trend in ceolomates

Back 20

protostomes & deuterostomia

Front 21

Protostomes

Back 21

-spiral cleavage-diagonal to the polar axis
-determinate cleavage-fate of daughter cells fixed
-blastopore becomes the mouth first
-mesoderm splits & widens into the coelom. "Schizocoely"

Front 22

Deuterostomes

Back 22

-Radial cleavage-parallel to the polar axis
-indeterminate cleavage-fate of daughter cells not fixed
-blastopore becomes the anus first
-mesoderm forms as "outpackets" , known as "enterocoely". The outpockets pinch off and become pouches.The cavity within the puches become the coelom.

Front 23

division of protostomes

Back 23

Lophotrochozoa & Ecdysozoa

Front 24

Ecdysozoa

Back 24

protostome animals that shed and replace their outer covering by molting or "ecdysis"

Front 25

Sponges

Back 25

phylum: porifera
evolved from: chaonoflagellates
have: choanocytes

Front 26

choanocytes

Back 26

collar cells-flagellate cells. make up the inner layer. create the water current that brings food and oxygen to cells and carries away CO2 and other wastes. Trap and phag food.

Front 27

spongocoel & Osculum

Back 27

In a sponge, water enters thru the central cavity, spongocoel, and flows out of the osculum.

Front 28

porocytes

Back 28

in sponges these form the pores. Regulate the diameter of pores by contracting.

Front 29

Spicules

Back 29

skeletal spikes. made by the amoebid cells. consist of calcium carbonate or silica.

Front 30

Amoebid cells

Back 30

secrete fibers for support. Transfer nutrients. Secrete spicules (hard) & spongin (soft).

Front 31

suspension feeders

Back 31

sponges are adapted for trapping & eating whatever food. food is trapped along the choanocytes. Food is either digested (collar cell) or tansferred to the amoebid cell for digestion and transport of nutrients to epidermal cells.

Front 32

Sponge reproduction

Back 32

-In asexual reproduction a fragment breaks off and forms a new sponge.
-Hermaphrodites: produces both egg & sperm. zygote develops into a larva. which attatches to an object for a sessile life.

Front 33

3 classes of Cnidaria

Back 33

-Hydrozoa (hydras)
-Scyphozoa (jellyfish)
-Anthozoa (corals)

Front 34

shape of cnidarians

Back 34

polyp and medusa

Front 35

cnidocytes

Back 35

stinging organelles. that contain stinging "thread capsules" known as nematocysts.

Front 36

blind sac of cnidarians

Back 36

diploblastic.
ectoderm- epidermis
endoderm- inner gastrodermis.

seperated by a mesoglea

Front 37

bicnidarian

Back 37

polyp give rise asexually to medusa. they reproduce sexually & the zygote develops into a larva, which turns into a polyp.

Front 38

class and shape of cnidarians

Back 38

class scyphozoa: medusa
class anthozoan: polyp

Front 39

planula

Back 39

fertilized egg of a polyp

Front 40

Ctenophora

Back 40

comb jellies. like medusa of cnidarians but without cnidocysts