choi organismal exam 3

What is the most abundant protein in human cell membranes?

Collegen

What protein in human cell membranes is NOT found in plants or fungi

Collegen

What is the ordering for cells and tissues?

Cells<Tissues<organs<organ system<organism

Human Reproduction cycle?

Zygote—>Cleavage(division without cell growth)—>blastula & blastocoel—-Gastrulation—>Gastrula

Gastrulation

One end of the embryo folds inward and expands. Results in Ecto, Meso, and Endoderm

Which layer of embryonic tissue is only found in bilateral animals?

Mesoderm

Which has a mesoderm Diploblast or Triploblast

Triploblast

Larval Stage

Sexually immature form that is morphologically distinct from the adult. Usually eat different food, different habitat

Hox Genes

Regulatory genes in the development of body segments and structures

Body plans

Morphological and developmental traits integration into a functional whole - the animal

Ectoderm

Outermost germ layer. Gives rise to outer covering(exoskeleton). In some phyla gives rise to nervous system

Ectoderm

Gives rise to lining of digestive tract/cavity and lining of organs

All bilateral animals have how many germ layers?

3. Triploblastic

Mesoderm

Between endoderm and ectoderm. Forms muscles nad some organs

Body Cavity

Almost all animals have one. Space between endoderm and ectoderm where mesoderm would be in bilateral animals. Structural support and transport of nutrients, gases, and wastes

Coelom

Greek for “hollow'“. Derived from mesoderm—>found in triploblastic. Enables internal organs to grow and move independently of outer body wall.

Hemocoel

Triploblastic. Between meso and endoderm. Contains hemolymph

Hemolymph

Analogous to human blood. Functions in internal transport of nutrients and waste. Circulated through open cavity by heart.

Why don’t some triploblastic animals have a body cavity?

Thin, flat bodies allows for diffusion of nutrients without a transport system.

Protosomes

Mouth develops from blastopore first

Deuterostome

Anus develops from blastopore first.

5 Things to know about animals within the phylogenetic tree

All share common ancestor(monophyletic)

Sponges are sister group to all other animals

Eumetazoa is a clade of animals with tissues(true animals)

Most animal phyla belong to clade Bilateria

3 major clades of bilaterian animals - Deuterostomia, Lophotrochozoa, Ecdysozoa

Deuterostomia

Hemichordates(acorn worms) invertebrate

Echinoderms(sea stars and relatives) invertebrate

Chordates vertebrate

Lophotrochozoa

Entirely invertebrates.

Members can have Lophophores - crown of ciliated tentacles that surround the mouth and function in feeding. Lophos - crest. Pherein - to carry

Ecdysozoa

Excrete external skeletons(exoskeletons)

Nematodes, athropods

Grows and molts out of exoskeleton via ecdysis

Phylum Porifera

Sponges. Sessile/sedentary(fixed in one place)

Filter feeds

Lacks true tissues. Not a true animal

Basal animals - diverged from other animals early in history of group

NOT eumetazoan

Hermaphrodites - both male and female

Amoebocytes

Phylum Porifera

Amoeba-like cells and move by pseudopodia

Totipotent - able to become other types of sponge cells.

Spongocoel

Central cavity of sponge

Osculum

Opening connecting spongocoel to environment

Choanocytes

Flagellated cells engulf bacteria and food by phagocytosis

Hermaphrodite

Both male and female producing sperm and eggs. Ex. Sponges

Cribrostatin

Kills cancer and penicillin-resistant strains of streptococcus spp. Produced by sponges

Phylum Cnidaria

Eumetazoan - true animal

Sessile and motile hydras, corals, jellies

Central gastrovascular cavity - mouth and anus

No Brain

What are the 2 variations in Cndarians?

Polys - large sessile. Hydras and sea anemones

Medusae - smaller, motile. Free-swimming jellies.

Some have both during their lifecycle

Cnidocytes

Special cells within tentacles. Protection+capturing prey. Contains Nematocysts

Nematocysts

Stinging thread that can penerate the body of prey. Within Cnidocytes.

What phylum of animal has no brain?

Cnidaria

What are the 2 clades of Cnidaria?

Medusozoans - produce a medusa

Anthozoans - only exist as polyps

Scyphozoans

Medusozoa. Jellies. Spends most of life in medusa stage

Cubozoans

Medusozoa. Box jellies. Spends most of life in medusa stage. Chironex fleckeri - one of the deadliest organisms known.

Hydrozoans

Obelia, siphonophores

Alternates between polyp and medusa

Most of life in polyp stage

Anthozoa

Sea anemones and corals

Only polyps

Secrete exoskeletons of calcium carbonate

Coral reefs

Coral Bleaching

Coral and Algae are symbiotic. Increase in temperature or pollution stresses algae. Algae leave and leave coral bleached and vulnerable.

Lophotrochozoa

Bilateral symmetry

Triploblastic

Most have digestive track with two openings

Lophophores

Phylum Platyhelminthes

Flat worm. Flukes, tapeworms. Not all parasitic though

Triploblastic but no body cavity

Eyespots to detect light. Prefers dark environments

Planarians

Platyhelminthes

Free-living flatworms found in ponds and streams

Feed on dead animals and move by cilia.

Non-parasitic

Asexual and sexual reproduction. Hermaphroditic

Trematodes

Platyhelminthes

Parasitic

Requires intermediate host before infecting final host

Asexual and sexual

Ex. Blood flukes—>snails—→humans

Tapeworms

Platyhelminthes

Adults live mostly in vertebrates

Acquired through undercooked meat

Lack mouth and cavity

Absorb nutrients in host’s intestine through body surface

Scolex

“sucker” for attachment to human intestinal lining. Tapeworm

Proglottid

Tapeworm. Long “ribbon” of units; consists of thousands of fertilized eggs. Released from posterior end of tapeworm and leaves in feces

Phylum Syndermata

Used to be Rotifera and Acanthocephala

Rotifers and Acanthocephalans

Rotifers

Phylum Syndermata

“Wheel-bearer”

Parthenogenesis - Asexual reproduction. Some species only have females that produce more females from unfertilized eggs.

Some reproduce sexually under certain conditions. i.e. high levels of crowding

Acanthocephalans

Sexually reproducing parasites in vertebrates(all). Lack digestive tract

Spiny-headed worms. Curved hooks on the anterior end

Triploblastic

Can manipulate behavior of intermediate hosts to reach final hosts better.

Phylum Ectoprocta

Lophotrochozoan.

Ectoproct - “outside anus”

Bryozoans - moss animals. resemble moss

Bilateral, lophophores, have a coelom

Brachiopoda

Lophotrochozoan

“Lamp shells” - resembles clams and hinged-molluscs

All marine

Bilateral, lophophores - opens shell to let water flow throuhg, coelom

Phylum Mollusca

Lophotrochozoans

Snails, slugs, oysters,clams, octopuses, squids (100,00 species)

2nd most diverse (behind arthropods)

Soft-bodied. Secrete shell made of calcium carbonate

Many are hermaphrodites

Mollusca - Foot

Muscular structure for movement

Mollusca - Visceral Mass

Contains internal organs

Mollusca - Mantle

Folds of tissue that secretes a shell. In many, the mantle extends beyond visceral mass creating mantle cavity - water-filled chamber.

Mollusca clade - Polyplacophora

Chitons

Marine

Oval-shape with 8 dorsal paltes

Mollusca - Gastropoda

Snails and slugs

~75% of all living molluscs

Marine but some in freshwater

Some adapted terrestrially

Gastropoda - Shell

Coiled shell - reduced surface area and better protection but heavier and slower movement

Operculum

“door” that seals the shell of mollusks

What do mollusks use to feed?

Radula

Gastropoda asymmetry is a result of what evolved trait?

Torsion to move the mantle cavity to the front

Bivalvia

Clams, oysters

Aquatic

sedentary/sessile

Shells divided into 2 halves

No distinct head and radula has been lost

Eyes and sensory tentacles along outer edge of mantle

Gills - feeding and gas exchange

Bivalvia - suspension feeders

trap small food particles in muscus. Cilia moves to mouth

TYPE of filter feeder

Cephalopoda

Marine predators

Squids, octopuses, cuttlefishes, chambered nautiluses

What is the only clade of molluscs that has a closed circulatory system?

Cephalopoda

Chromatophores

Squids use to camoflage

Annelida

Body resembles little rings

Segmented worms

Coelom but no hemocoel

Errantia

Sedentaria

Errantia

“traveling”

Mostly marine

Mobile and most predators

Parapodia

“beside feet” Used for locomotion. Cirri - fused bundles of cillia

Sedentarians

Less mobile than errantia

Some burrow through sediment or soil

Leeches

Sedentarians

Parasitic

Ectoparasite. Outside body

Secretes anesthetic

Hirudin - prevents blood coagulation

Earthworms

Sedentarian

Till and aerate soil

Improve water infiltration

Enriches soil

Cutaneous respiration(through skin

Hermaphrodite

Clitellum

Thick ring-like glandular band next to head of sexually mature worm

Ecdysozoa

Shed a cuticle as they grow

Ecdysis

Molting/shedding

Nematoda

Ecdyzoa

Most ubiquitous of animals

Do not have circulatory sytstem - Hemocoel

C. Elegans

Nematoda. Useful in research. Over 100 genes associated with human disease

Trichinella Spiralis

Causes Trichinosis

Raw or undercooked pork/meat

Arthropoda

Billion billion arthropods

Mostly insects

Arthropod - segmented ecysozoan with hard exoskeleton and jointed appendages

What kind of special respiratory system do arthropods have?

Tracheal system - branched air ducts lead into the interior of body from pore in the cuticle

Chelicerates

Sea spiders, horseshoe crabs, scorpians, ticks, mites, spider

Lack antennae

Simple eyes

Eurypterid - earlier species

Many are arachnids

How many appendages do Chelicerata have?

6 - Chelicerae, Pedipalps - sensing, feeding, defense, reproduction, 4 Pairs of walking pairs

Myrapodia

Centipedes and millipedes

Pancrustacea

Includes all crustaceans and insects

Crustaceans

Antennae - Only arthropod with 2 pairs

Mouthparts(hard mandibles)

Walking legs on thorax

Tail

Isopod

Pill bugs and wood lice

One of the largest groups of crustaceans

Decapods

Crustaceans

Loberster, crayfish, crabs, shrimp

Copepods

Many are planktonic crustaceans

Barnacles

Crustaceans. Sessile. Anchors to rocks and boat hulls

Insects

Hexapoda

Consumes lots of plant matter

Predators, parasite, decomposers

food chain

pollination

protein

Deuterostomia

Mouth second

Echinodermata

Spiky skin. Seastars, brittle stars, urchin, feather stars, sand dollars, sea cucumbers

Coelom

Unique water vascular system

Asteroidea

Sea stars

Grips due to adhesive chemicals

Sea daisies

Asteroidea

3 known species

Crinoidea

Sea lillies - attached to substrate by a stalk

Suspension feedrs

Feather stars

Holothuroidea

Sea cucumbers

no spines and reduced exoskeleton