bio unit 5 - protostome animals

coel

cavity (usually fluid filled)

ontogeny

development of an individual

choanoflagellates

closest living relatives to animals

collagen

protein that holds tissues and organs together, only in animals

4 types of tissue in animals

1. connective tissue

2. epithelial tissue

3. muscle tissue

4. nervous tissue

connective tissue

holds tissues and organs together

epithelial tissue

covering on and in organs made of tightly packed cells

muscle tissue

cells made of protein fibers for contraction (movement), only in animals

nervous tissue

made of neurons that transmit signals coming from environment (response), only in animals

cleavage

mitosis without cell enlargement

blastula

hollow ball of cells

blastocoel

fluid filled space inside blastula

gastrulation

developmental process that happens in the blastula involving invagination/ infolding on one end of the blastula

archenteron

becomes digestive tube in mature animal

blastopore

entrance (hole) to archenteron that either becomes mouth or anus of the digestive tube

endoderm

embryonic layer in gastrula that becomes digestive tube covering

ectoderm

embryonic layer in gastrula that becomes epithelium and nervous system

larva

immature stage of development after gastrula embryo that cannot reproduce and looks different and lives in different habitat than adults

what is the function of a larval stage?

eating for growth, usually in a more protected environment

metamorphosis

developmental change in juvenile/ adult stage of development

homeobox genes

highly conserved sequence of homeotic genes that regulate body part identity during development, only in animals

homeotic genes

master regulatory genes that control body development in all multicellular kingdoms

pores

holes in epidermis that pull in H2O with food particles

spongocoel

central body cavity that water is pulled into

osculum

hole at top of sponge where water exits

choanocyte

cells that line inside of spongocoel

what are the two functions of choanocytes?

1. directing the flow of water 

2. capturing food particles from water (with colllar of microvilli)

amoebocytes

move in a gelatinous layer (mesohyl) using pseudopodia

what are the 3 functions of amoebocytes

1. taking food particles from choanocytes (by phagocytosis) and distributing nutrients throughout sponge body

2. totipotent cells make other cell types and new sponges

3. make spicules

totipotent

cell with the ability to make new individuals and different cells

spicules

skeletal elements for support

fragmentation

fragments fall off of an individual and become new individuals

hermaphrodite

aka monoecious, one body can make both gamete types

economically important sponges

→ antibiotics (cribrostatin)

→ bathing sponges (spongin)

spongin

protein that makes spicules in some sponges

kingdom Metazoa (animal) S-D characteristics

1. internal digestion

2. collagen

3. no cell wall

4. gametic meiosis

5. multicellularity

6. homeotic genes

Eumetazoa S-D characteristics

1. true tissues from germ layers

2. gastrulation

3. Hox genes

germ layer

embryonic layer of cells in gastrula

2 germ layers in diploblastic animal

1. ectoderm

2. endoderm

Hox genes

control anterior - posterior identity during development

2 types of Cnidaria

1. polyps

2. medusa

polyps

sessile, attached to substrate on aboral end and oral end points up

medusa

motile, aboral end points up and oral end points down

gastrodermis

layer of cells that comes from the endodermis and functions in digestion

gastrovascular (GV) cavity

internal space lined by gastrodermis

what constitutes an incomplete digestive system?

only one hole for both ingestion and egestion

what are the 3 main functions of a gastrovascular cavity?

1. digestion

2. gas exchange

3. hydrostatic skeleton

hydrostatic skeleton

fluid-filled cavity that functions in flexible support and rigid structure for muscle contraction and attachment

cnidocyte

cells that line tentacles for helping capture prey with organelles called chidae

nematocyst

type of cnidia with venom

nerve net

diffuse network of neurons (nerve cells)

which two phylums do not have a central nervous system?

Porifera (sponges) and Cnidaria

how does the nerve net function in Cnidarians?

sensory cells function in detecting changes in environment and are connected to nerve cells which are connected to contractile extensions (muscle fibers that extend from epidermal cells that contract)

gonads

animal gametangia, ovaries (make egg cells/ ova) and testes (make sperm)

economically important Cnidaria

→ green fluorescence protein (GFP)

ecologically important Cnidaria

→ coral reefs (CaCO₃ exoskeleton)

→ zooxanthellae

zooxanthellae

dinoflagellate photosynthetic protists that form mutualism with corals

protist provides carbs

animal provides sunny place to live that is protected and fertilizer for protist (ex: ammonia)

Bilatera S-D characteristics

1. bilateral symmetry

2. triploblastic

triploblastic

3 germ layers in gastrula embryo

what are the 3 germ layers of a tribloblastic animal?

1. ectoderm = outer

2. endoderm = inner

3. mesoderm = middle

coelom

cavity lined by mesoderm

pseudocoelom

cavity lined by mesoderm AND endoderm

3 functions of coelom/ pseudocoelom

1. hydrostatic skeleton

2. cushion internal organs

3. gives internal organs freedom to move

Protostome development

1. spiral and determinate cleavage 

spiral- plane of cell division is diagonal

determinate- embryonic cell’s fate is determined early in development

2. coelom formed from tears/ rips in mesoderm

3. blastopore becomes mouth

trochophore larvae

in most Lophotrochozoa, ciliated ball (larva) that swims as zooplankton before becoming adult

lophophore

group of ciliated tentacles that are used for suspension feeding

protonephridia

excretory structures in Platyhelminthes and Rotifers that function in regulating osmotic balance

which 2 phylums has no coelom (acoelomate)?

Platyhelminthes (flatworm) and Rotifers

pharynx

muscular part of digestive system at anterior end behind mouth

what is the function of a pharynx?

pulling food further into the digestive system

central nervous system

nervous system with anterior brain attached to nerve cords

what does the central nervous system look like for most invertebrates?

brain + 2 ventral nerve cords

cephalization

evolution of a head that holds a brain

brain

detects changes in the environment and transmits information to the rest of the body using nerve cords

lateral flaps

detect chemicals (food) in the environment (similar to smell)

cestodes

parasitic tapeworms, live in digestive system of host (intestines), no digestive system because they steal nutrients directly through body surface

scolex

at anterior end, attaches tapeworm to host’s intestinal lining

proglottids

in Platyhelminthes, body sections that contain both gonads, self fertilize, proglottids loaded with fertilized eggs leave digestive system

trematodes

parasitic flukes, dioecious

alimentary canal

complete digestive system with mouth (anterior, ingestion) and anus (posterior, egestion), more complex and more efficient nutrient absorption

parthenogenesis

asexual reproduction because egg cell is made by mitosis and no sperm is involved

what are the 3 main body parts of Molluscs?

1. foot

2. visceral mass

3. mantle

visceral mass in Molluscs

including coelom, where internal organs are located

mantle

dorsal body layer that covers visceral mass and functions in secreting CaCO₃ shell

mantle cavity

fluid-filled in aquatic species, holds the lungs/ gills, exit for digestive system and excretory system

radula

feeding structure at mouth made of chitin with many tiny teeth usually used for scraping food off substrate

circulatory system

circulates fluid (blood) carrying O₂ and CO₂

open circulatory system

not enclosed in vessels

which phylums have open circulatory systems?

Molluscs, Annelids, Arthropods

hemolymph

circulatory fluid, blood cells and interstitial fluid

2 functions of metanephridia

1. regulate osmotic balance

2. remove nitrogenous waste

grazing radula

scrape algae off substrate for feeding in Chitins

what are the 4 classes of Molluscs?

1. Chitins

2. Gastropods

3. Bivalves

4. Cephalopods

sedentary

not sessile but sit on substrate

pen

reduced shell in Cephalopods, internal in most

closed circulatory system

blood/ circulatory fluid enclosed in vessels

worm

long, narrow invertebrate animal, body has high SA:V

metamerism

body divided into repeating segments, divided by septa

what is the function of metamerism?

more sophisticated movement because you can move different parts of the body independently

chaetae

bristles made out of chitin embedded in body wall in Annelids, function in locomotion by providing traction