Bio Exam 3

What is an amimal?

6 things

Key things that make them such efficient consumers

Slides; Heterotrphic, tissues formed from layers of embyronic cells, process foods inside their bodies via digestive systems, nerve and muslce cells, motile(capture prey)

Notes; Eukaryotes, can breathe, OSPITHOKONTS

History of animals

Animals occured 565 million years ago in rock deposits, edicaran fuana, looked very different from animals today, began as soft bodies, taphineous

Animals arose in what period

These fossils typically include

Cambrain rocks preserved skeletons that can be related to

Cambrian period

Skeletons made of silica, calcium carbonate, calcium phosphate materials

Present-day phyla including mollusks and echinoderms

The Cambrian explosion marked

a time of rapid diversification

What is one of the primary reasons given to explain why there are very few fossils from the earliest (pre-edicaran animals)

The earliest animals were small and soft-bodied and did not have parts that could be fossilized easily

What two extinctions removed a large percentage of organims from the planet

Permian and Cretaceous

what classifies a mass extinction

events in which at least 75 percent of the existing species go extenct within a 2 million year period

First Mass Extinction

what moslty went extinct and due to what and moslty where

End- Ordovician

57 percent of Marine genera extinct, in tropical areas moslty

Causes: rapid glaciaiton/sea-level fall, climate cooling

Seocnd Mass extinciton:

what went extinct, due to what

End-Devonian

70 percent of marine invertebrates extinct

causes: occean anoxia, climate change, volcanism

3rd mass extinction

largest what

what went extinct

causes

what survived and therefore became dominant in the oceans

End Permian

largest mass extinction

95 percent of marine species extinct, 70 percent of terresterial species extinct

cuases:massive volcanism( Siberian traps), climate warming, ocean acidification, oxygen loss

Brachiopods, a diverse gorup present in Ordovician fossils surivved this extinction and became a dominant group in the oceans

4th mass extinction

what went extinct

what rised

causes

End triassic

52 percent of marine genera extinct

rise of dinosaurs

cuases:volcanism, c02 increase, cliamte warming

5th mass extinction

what went extinct

causes

End KPg

62 species extinct

all non-avian dinosaurs

Causes: asteroid impact(iridium) climate disruption( Deccan traps)

Dinosaurs dominated _ _ from 210 million years ago until the end of the Cretaceous

Mammalian lineages originated 210 million years ago, but were typically _ _ __ species

After the mass extinction of the dinosaurs, mammals radiated and became the first dominant vertebrates in _ _

teresterial ecosystems

small, nocturnal, tree-dwelling spcies

terresterial ecosystems

How many mass extinctions have occured, what did this lead to

5 times, lead to rapid decline of organisms then leads to complexity/diversity due to opening of niches

How did mass extinctions contribute to current patterns of biodiversity

Species that remained after each extinction were able to radiate, new adaptations arose, and these adaptations produced the divesity seen today

where is multicellularity blastula on phylogenetic tree

on branch that holds poriferia

whayt branch is multiple tissues gastrulation on

sister taxa branch of Cnidaria and bilateria

which branch is bilateral complex organs on

bilaterial symmetry complex organs

which organism on phylogenetic tree are single celled

Chonaflagelletes, at top

most primitve organism on phylogenetic tree

pniferia

The phylogney suggests animals are closely related to chonaflagelletes, however animals are different friom chonalflagelletes because they have three differences:

1. Persistent multicellulairty

2. Embryonic cell movement

3. Simple tissues

Poriferia(sponges)

Found where:

Lack:

how are cells organized:

resembles:

Found at bottom of ocean in bozz like coral reef systems

Lack true tissues

Simple organized cell fashion through whole basal body

flower vase , hard structure, many small pores along sides, larger opening at top

Pniferia(continued)

Suspesion feeders:

what allows nutrients in/out of

Suspension feeders> attatched to cessle, attatched to substrate on the sediment

Feed by drawing water containing food particles/dissolved organic material into interiors

Pniferia

chanoycytes

mesophyll

cells in sponge, water current creates coordinated beating pattern in systematic function, draws water into the body through pore sysmte, and outward through the vase openign, look like chonaflagelletes, all throughout epidermis tissue

Mesophyll has ambeosites which function in skeleton formation and disposal of nutrients, Skelton is made of silica, calcium carbonate

how do the choanyctes that line the cavity capture the circulating water that contains food particles and dissolved organic matter

Endocyotis

what acts as the sponge’s skin

tough cells on the outer surface of the sponge act as the sponge’s skin

what acts as the current that draws water into the cavity in the pniferia(sponge)

what acts as reproductive cells

what respond to external environment

flagelleated cells called chanoycytes

gel-like Mesophyll cells form spicules and generate reproductive cells

cells that line hte exterior sense and respond to the external environment

cells making up sponges retain much of the

Individulaity of chanoflagellete cells while having the benefits of multicellularity

Which statement correclty compares Poriferia, Cnidaria, and bilateria

Porifera lack true tissues, cnidaira have true tissues and radial symmetry, and bilateria have bilateral symmetry and three embryonic layers

Which of these correctly describe deuterostomes

they have three embyroonic tissue layers and the blastopore becomes the anus

Cnidaria

what group are they in a sister taxi with on on phylogenetic tree

contain what

what makes tissue and organ devlopment possible

what animals do they cointain

with bilateira as sister taxi

Contain true, well-defined tissues

These epethelial lined compartments make tissue and organ development possible( muscle cells for movement in jellyfish, well formed digestive system)

The phylum that contains jellyfish, sea anemones, corals

Cnidarian Body Plan

1. 
   

1. Mouth surronded by tentacles armed with stinging cells

1 continued

what are nematocysts in cnidarians

Specialized stinging cells located in the epidermis , harpoon like organelles, often contian powerufl nuerotoxins

1 contiuned

how do cnidarians get their prey

5 steps

1. Harpoon like nematocysts are coiled within epidermal cells

2. Contact triggers contraction of the nematocysts and ejection of the harpoon with its toxin-delivering tube

3. Nematocysts of some cnidarinas inject toxins into predators of prey

4. Prey is digested in gastric cavity

5. enzymes break down ingested food into molecules that can be taken up by the cell lining the cavity by endocytosis

Cnidarians body plan

2.

Closed internal gastric cavity of extracelular digestion and excretion, polyp and medusa

Cnidarian Body plan

3. 
   

Mesogia surronded by epidermis(outside) and endodermis(inside)

Mesogia is a gelantanious mass (water and collagen) that makes the jelly of jellyfisn and provides hydrostatic skeleton

Cnidarians:

Medusozoans vs anthozoans

Medusozoans- Medusa producing cnidarinas, life cycles alternate between stages

Anthozoans- polyp-only cnidairns, lack Medusa stage

how do cnidarinas reproduce to produce colonies

in soft corals :

Pneumataphore:

Produce asexually

in soft corals individual members of the colony are similar in form and function

gas filled float that sits on top of the organism fior buocancy, and the coolony sits below it

Portugese Man of war jelly:

members of colony differentiate to serve disticnt functions such as prey capture(dactylizooids) feeding(gastrozoids) and reproduction( gonozoids)

In the past, sponge and cnidarian species were referred to as lower or primitive animals. What suggests that the terms lower or primitive are not useful as descriptors for these organisms

These groups have been around for millions of years, therefore their evoltionary pathway has been succesfful in spite of limited complexity.

if you cut a sponge and cinadarian down the middle would they look the same

sponge- few cell times, not organzied into tightly coordinated tissues or organs, SO NO THEY ARE ASSYMETRICAL

Cnidarian- simple complex tissues but do not have complex organs, SO YES THIR BODIES HAVE AN AXIS THAT RUNS FROM MOUTH TO BASE RSDIAL SYMMETRY.

How do animasl with radial symmetry ( cnidarisns )move

Motile vs stationary

Motile cnidarisn move up and down in the water column by flexing muscles around their bell like bodies

Stationary cnidarians(sea anemones or corals) wave its ring of food-gathering tentacles in all one directions at once

Bilateria

Most animal species are

with cnidarians contain:

also contain

what does their anatomical complexity lead to

what symmetry do they have

most animal species are bilaterians

With cnidarians, cointain true, well-defined tissues

Contain complex organs that develop from a triplobnastic (three-germ layer) embryo

Anatomical complexity leads to unique types of movement, behavior, digestion, and gas exchange

Bilaterial symmetry

one plane of symmetry

bilaterial symmetry, if cut in different directions the halves would look the same

radial suymmetry

many planes of symmetry, cut these organisms in different directions havles would look the same, body axis that runs from mouth to base, many planes of symmetry around axis

Bilaterian bodies have a

disticnt front and back, top and bottom, right and left, single plane of symmetry runnng between right and left at the MIDLINE

Movement in animals with bi laterial symmetry

Animlas move in one horizontal direction to capture prey, find shelter, or escape from enemies

ie crab

Cephalization

nervous sytstem tissue, including specialized organs such as eyes, becomes concentrated at one end of body, notabel feature of many bilaterian animals includign cephalopod

cephalkization continuted

as the quality and amount of sensory information taken by an animla increases, their

examples of animals

brain size and complexity also increased

flatowrms , molluscuis, arthopods, and vertebrates each have a distinct head region with specialized sense organs

cehphalization is considered an adaption for what which does what

this is imporant for

locomotion, allows animlas to process sensory information from the environment quickly enabling them to maek a suitable response

adaption against predation- better detect and capture prey and can avoid predators as well

Segmenation

Segmentation is the organization of the body into repeated units along the anterior/posterior (head-tail) axis

arthropods, annelids, adn chorodates are three animal phyla known for a segmented body pain

true or false: all organimss with bilateral symetry also show segmentation

true

Biologists divide animals into two groups based on number of germ layers that devlop from teh blastula

diplobasts

triploblasts

Diploblasts- animals that devlop into embyros with two germ layers (enoderm and ectoderm) from which the adult tissues deveop CNIDARIANS

Triploblasts- animals that devlop from embryos with three germ layers(mesodermal lies between endodermis and ectoderm and develops into muscles and coonective tissues) BILATERIANS

According to the phylogenetic tree shiown, which answer correctly liusts the sequence in which multicellularity tissues and bilateral symmetry arose from oldest to most recent

multicellular, tissues, bilateral symmetry

Dueterosomes

blastopore becomes anus (echnioderms chordates)

prostostomes

blastopore becomes the mouth

annelids, molluscs

Molecular sequence data support the protosome-deutersome groupings of

bilaterina animals and show that protosome animals can be further divided into two groups:

lophotrochozoands-molluscs, annelkd worms

ecdysozoans- insdects and other arthopods

three forms of bilaterians based on the presence of absence of a cavity, coleum, in tissues surronding the gut

Coelom- fluid filled body cavity that cushions the internal organs against hard blows to the body and enables the body to turn without twistng organs

acoelmoates

no body cavity

hemocoel

body cavity that does not completely surrond internal organs

coelomates

with a body cavity only