DFF lecture 5

what are the 3 major animal clades

-lophotrochozoans -ecdysozoans -deuterostomes

what are mammals

amniotes that have hair and produce milk, mammary glands, sweat glands, 4 chambered heart, teeth varied

what are the most primitive tetrapods

amphibians - frogs (no tail as adults), caecilians (limbs lost), moist skin, require water for eggs (no shell), wet habitats

what is a blastula

an animal embryo at the early stage of development when it is a hollow ball of cells

what is a gastrula

an embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells

what are deuterostomes?

animals that develop the anus before the mouth; chordates and echinoderms

what are protostomes

animals that develop the mouth before the anus; arthropods and mollusks

what are diploblastic animals

animals that have 2 body layers; distinct organ system; central gastrovascular cavity; non-centralized nerve net; aquatic body supported by water

which animal phylum is the most successful

arthropods, most species-rich

what are ecdysozoans

arthropods, nematodes; shed exoskeleton to grow

what are tardigrades

arthropods; microscopic, when environmental conditions become unsuitable they pull in their limbs and head; allows them to withstand extreme temperatures

what are nematodes

arthropods; roundworms; no segmentation; can act as scavengers, predators, or parasites

advanced animals have...

bilateral symmetry

what are lophotrochozoans

bryozoans, molluscs, annelids; common larval form, feeding apparatus

what are jawed fishes

cartilaginous fish: sharks, rays; bony fish (ray-finned), lobe-fins

sponges inner surface is made up of

choanocytes; flagella beat to draw water through pores to central cavity

what is an example of a diploblastic animal

comb jellies, jelly fish, corals (ctenophores, cnidarians)

what species are considered arthropods

crustaceans (lobster), hexapods (grasshopper), myriapods (millipede), chelicerates (horshoe crab, spiders)

what is the endoderm

innermost germ layer

what are vertebrate innovations

internal skeleton, bone, jointed fins, nares, terrestrial limbs, amniotic eggs (dry conditions)

what are sponges

invertebrate animals that usually have no body symmetry, tissues, or organs

most animals are...

invertebrates

what are examples of chordates

lancets, tunicates, vertebrates

what are bryozoans

lophotrochozoans; colonial

what are rotifers

lophotrochozoans; have a ciliated corona- sweeps food into mouth; some species - only females

what are molluscs

lophotrochozoans; have a foot for locomotion; internal organs; mantle (secretes shell) -gastropods (snail) -bivalves (clams) -cephalopods (octopus)

what are flatworms

lophotrochozoans; simple bodies, most are internal parasites

what are annelids

lophotrochozoans; worms

earliest and simplest animals are...

marine

what type of symmetry do echinoderms have?

most are radially symmetric as adults; larvae are bilaterally symmetric; move and feed using tube feet

what are arthropods

phylum that is part of invertebrates that have an exoskeleton (external skeleton), a segmented body, and jointed appendages

what are types of mammals

prototherians (lay eggs) marsupials (newborns move to pouch) eutherians (more developed at birth)

simpler animals have...

radial symmetry

what are reptiles

scaly animals; turtles, tuataras, squamates (snakes, lizards), crocodilians, dinosaurs

what do simpler ecdysozoans do to grow

shed their exoskeleton

what is central gastrovascular cavity

single opening is both mouth and anus; tentacles trap prey and sweep into mouth

what are characteristics of lophotrochozoans

have a lophophore (feeding structure) and a trochophore (free-living larval stage)

what is a triploblast

3 germ layers; has an endoderm, ectoderm and mesoderm

what are characteristics of chordates?

dorsal, hollow nerve cord; a notochord; a tail that extends beyond the anus; and pharyngeal pouches

what are deuterostomes

echinoderms, hemichordates, vertebrates; mouth forms second

what is an animal

eukaryotic, multicellular, heterotrophic organism that obtains nutrients by ingesting food; motility attained through muscles, nerves, skeleton

what are amniotes

tetrapods that have a terrestrially adapted egg; reptiles and mammals

what is the ectoderm

the germ layer covering the embryo's surface

animals are monophyletic which means

they descended from a common evolutionary ancestor; thought to resemble colonial choanoflagellates