Bio 102 Test 2 Prt 2

Front 1

Notochord

Back 1

a longitudinal flexible rod between the digestive tube and nerve cord This is present in all chordate embryos(and some adults) It provides support and muscle attachment In most vertebrates a jointed skeleton will eventually develop This in humans is the intervertebral discs

Front 2

Dorsal hollow nerve cord

Back 2

develops from the ectoderm that rolls into a tube Other animal phylum have solid nerve cords

This develops into the central nervous system (brain and spinal cord)

Front 3

Pharyngeal clefts

Back 3

a series of pouches separated by grooves along the pharynx In most chordates these grooves will develop into slits that open to the outside of the body These allow water to enter the mouth and pass out the body(without going down the

digestive tract) Some animals uses these for filter feeding, others have been modified into gills for gas exchange

=In Tetrapods(terrestrial vertebrates) these play important rolls into the developmmt of the ears and other structures

Front 4

Post-anal tail

Back 4

this skeletal and muscular extension provides a means of locomotion in aquatic animals In some species this is lost during embryonic development

Front 5

Urochordata Tunicates

Back 5

■ The 4 characteristics of chordates are present in its larval stage (which may only last a few minutes)

■ The larval form will swim until it finds a suitable substrate which it settles on It goes thuough metamorphosis, reabsorbing its tail and notochord while its nerve cord degenerates

The adults still maintains the pharyngeal slits for filter feeding The adults are commonly called sea squirts

Front 6

Cephalochordata Lancelets

Back 6

In the larval form these animals develop all 4 characteristics of chordates When it goes through metamorphosis into the adult form, these characteristics are retained (it doesn' t change all that much) The adult will bury into the bottom of the ocean and filter feed with cilia like tentacles

Front 7

Craniates

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are Chordates with a head The head consists of a brain, eyes and other sensory organs, and a skull These are different form other chordates because they have two clusters of Hox genes (the lancelets and tunicates have one cluster)

Front 8

The neural crest

Back 8

(which craniates have) is a collection of cells at the closing margin of the neural tube in the embryo These cells scatter throughout the body giving rise to teeth, some bones, the dermis of the face, different types of neurons, and Sensory capsules in the eyes

Front 9

Lampreys

Back 9

These are the oldest living lineage of vertebrates Most are parasitic, but they have no jaw Cartilage skeleton, with a layer of cartilage around the notochord with projections sticking out like vertebrae Larvae lives in feshwater, then migrate to the ocean

Front 10

Hagfish

Back 10

the least derived craniate lineage They do not have vertebrae or jaws(not vertebrates)

Front 11

Chondrichthyans

Back 11

Sharks and rays are the biggest and most successful vertebrate predators in the ocean Their skeleton is composed of cartilage with calcium deposits

They do have traces of bone can be found in their scales and at the base of the teeth.

Some also have a thin layer of bone on their vertebrae

Front 12

Shark buoyancy

Back 12

It gains buoyancy by having large quantities of Oil in its liver, but the animal is still very heavy causing it to sink when it stops swimming

Front 13

Sharks have three different methods of birthing

Back 13

●oviparous-lay eggs outside the mohers body

●ovoviviparous-eggs are retained in the oviduct, embryos arc nourished by an egg yolk, young are born after hatching

●viviparous-young develop within the uterus and obtain nutrients from the mother through a placenta

Front 14

Osteichthyes

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Bony fish-they have a endoskeleton of calcium phosphate These are the most abundant vertebrates They control their buoyancy in the water with a swim bladder, which they can fill with air to float up or empty to sink down

Front 15

There are two groups of bony fish

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Ray-Finned..... Most ot the fish we know The fins are supported by long flexible rays

Lobe-Finned Rod-shaped bones surrounded by a thick layer of muscle in their pectoral and pelvic fins

Two groups survive today Coelacanths (1938 found in Indian Ocean, 1999 found near Indonesia) Lungfishes (lives in stagnant freshwater swamps and ponds in Southern Hemisphere)

Front 16

Tetrapods

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Animals that have 4 feet This enabled them to colonize land and take on many new forms

Front 17

3 Groups of Amphibians

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Urodela- salamanders

Anura- frogs (have external reproduction The male grasps the female and stimulates her to release eggs while he releases sperm)

Apoda- limless Amphibians

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amphibian

Back 18

two Iives

Larval stage is aquatic(can be herbivore or carivore)

They lack legs and use their tail to swim

Gills are used for gas exchange

Once metamorphosis occurs,

the adults emerges from the water and typically has a terrestrial life stage

Tail is absent(in frogs)

Uses lungs (and skin) for gas exchange

Front 19

Amphibian decline

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is occurring at an alarmin grate ●Habitat loss

●Acid Rain

●fungal pathogens, specifically chytrid fungus

●Pesticides and herbicides

●Invasive species

●Climate change

●Pollution

Front 20

Amniotes

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Named for the amniotic egg with specialized membranes to protect the embryo Groups Include:

reptiles, birds, and mammals

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Reptiles

Back 21

have adopted several characteristics that enabled them to colonize and disperse over land, even in the most inhospitable environments

●Scales-create a water proof barrier which prevents desiccation

●They rely solely (for the most part) on lungs for respiration

●Eggs with a shell which prevents desiccadon

●International fertilization

Front 22

Tuatara

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Only occurs on islands off the coast of New Zealand Rats that came with humans during exploration devastated the populations

These lizard-like animals can live over 100 years

Differs from lizards because of skeletal structure.

Front 23

Lizards and snakes

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Lizards are the most numerous and diverse reptiles The smallest is 16 mm (this will fit on a dime) to the largest 3m (the Komodo dragon)

Snakes are legless lizards (some still have the remnants of hind limbs and pelvic bones)

All snakes are carnivorous and hunt(or sit and wait) for prey There are numerous adaptations snakes have for maximizing their hunting efforts

Front 24

Turtles

Back 24

All have a upper and lower shell fused to the vertebrae (typically the shell is hard) They are wide ranging from deserts, to the sea, to living entirely (almost) in ponds and rivers

Front 25

Alligators and Crocodiles

Back 25

Confined to warm regions of the earth They are largely adapted to aquatic habits Mainly freshwater Some venture in and occupy saltwater

Front 26

Birds (Aves)

Back 26

have undergone several modifications to enable

Flight Save on weight

-No urinary bladder

-Females have one ovary

-Gonads are small until breeding season

-Toothless

-Hollow bones (however, its skeleton is about the same weight as an equal size mammal)

-Wings and Feathers

■are endotherms They use their metabolism to maintain body heat

■They have the best eyesight of all vertebrates

■There are several species are flightless Emu, kiwi, rhea, ostrich, penguins

Front 27

Mammals

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●Mammary glands to produce milk ●Hair

●Fat layer under the skin ●Endothermic with high metabolic rates

●Diaphragm to ventilate lungs ●Large brains

●Differentiation of teeth

Front 28

Monotremes

Back 28

Platypus and Echidnas (spiny antcaters) Found only in Australia and New Guinea They are characterized as the only mammals that lay eggs They have hair, produce milk, but lack nipples Milk is produced by glands in the belly and clings to the fur

Front 29

Marsupials

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are born very early in development

■ It completes its embryonic develop while nursing in a pouch called a marsupium

■These include opossums, kangaroos, koalas, bandicoots, and others

■They are only found in Australia and North and South America

Front 30

Eutherians

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●Placental mammals

●They have a longer period of pregnancy than marsupials

●Embryonic development is completed within the uterus

Front 31

Primates

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They differ from other mammals

●Hand and feet for grasping

●Flat nails instead of narrow claws

●Skin ridges

●Larger brains

●Short jaws.

Front 32

Monkeys and apes

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are the only primates to have an opposable thumb

They can touch the ventral surface of all four fingers using their thumb

This can be used for gripping power and in humans

the bone structure has allowed precise control

■ The group hominoids consists of Mates called apes (gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans)

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Humans Homo sapiens

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differ from other hominoids by

●Standing and walking upright

●Larger brains capable of language, symbolic thought and use of complex tools

●Reduced jaw bones and jaw muscles

●Shorter digestive tract

■Despite these differences, their genome is 99% identical to chimpanzees

Front 34

Phylum Porifera

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Sponges marine and freshwater
Suspension feeders (filter feeder)
Food particles pass through body.
Are hermaphrodite produce both sperm and eggs

Front 35

Choanocyte (collar cells)

Back 35

Line the inside of the spongocoel (central cavity of the sponge)
Creates current to draw in water.
Food particles are ingested by phagocytosis.

Front 36

Amoebacyte

Back 36

Another specialized cell of the sponge which engulfs food particles to bring nutrients to other cells.

Front 37

Spicules

Back 37

The skeleton of the sponge.
Calcium carbonate
Silica (glass)
Spongin (protein)

Front 38

Cribrostatin

Back 38

Antibiotic produced by sponges
Can kill penicillin resistant streptococcus.

Front 39

Cnidaria

Back 39

Are the jellyfish and sea anemone.
Have tissue level organization. Are diploblastic with radial symmetry.
Have gastrovascular cavity(a sac with one opening)

Front 40

Polyp vs medusa

Back 40

Are attached to the substrate by their aboral end with oral surface and tentacles up waiting for pray(normally Sessile)
Free floating form with tentacles and mouth facing downward. Moving by current and contraction of body.

Front 41

Cnidocytes

Back 41

Specialized cells of Cnidaria function in both defense and capture of pray.
Some have
nematocysts.
Which are stinging capsules

Front 42

Platyhelmithes

Back 42

Flatworms
Bilateral symmetry
Triploblastic development.
Organ level of organization.
Has gastrovascular cavity

Front 43

Blood fluke

Back 43

Spend part of life cycle in snails and part in humans. They can live up to 40 years in a human host by releasing molecules that influence the immune system to tolerate them.

Front 44

Tapeworm

Back 44

Are parasitic Platyhelmithes
With a scolex head region with hooks that attach to the intestinal wall.
The eggs are contained in their proglottids which are release eggs during dedication.

Front 45

Rotifera

Back 45

Are about 50 microns to 2mm in size
Are pseudocoelomate and have a digestive tube with 2 openings (alimentary canal).

Front 46

Nemertea

Back 46

Proboscis or ribbon worms
Acoelomate but contain small fluid filled sacs
These are used hydraulically operating system which enables these worms to shoot out a proboscis which deliver toxin to pray
Has alimentary canal 2 openings and a closed circulatory system unlike flatworms

No heart Blood is pumped through vessels due to muscle contractions in vessel wall.

Front 47

Molluscs

Back 47

Has a foot for locomotion
Visceral mass which contains organs
Mantle folds of tissue over the visceral mass that secretes a shell
(Polyplacephora has an 8 plated shell)
Some have a mantle cavity that forms a water filled chamber containing the gills anus and excrete pores
Some have a radula that is used to scrape food.

Front 48

Gastropods

Back 48

Molluscs
Snails and slugs
Torsion is the twisting of the visceral mass that will have the anus and mantle cavity over the head.

Front 49

Bivalvia

Back 49

Molluscs clam oysters muscles and scallops
Shell is divided into two half and hinged with powerful Adductor muscle

Front 50

Cephalopoda

Back 50

Molluscs
Octopus squid cuttlefish and nautilus
Mantle covers visceral mass but squid it is reduced and not present in octopus
Nautilus is only Cephalopod today with a full shell
These are the only molluscs with a closed circulatory system well developed sensory organs and a complex brain.

Front 51

Annelids

Back 51

Segmented worms found in marine freshwater and terrestrial habitats

Front 52

Oligochoeta

Back 52

Few choeta bristles of chitin
Important for mixing soil
Are hermaphrodites but they cross fertilize
The clitellum secretes a mucus cocoon which slides down the worm picking up eggs.

Front 53

Polychoeta

Back 53

Most are marine worms they contain parapoda that functions in locomotion.

Front 54

Hirudinae

Back 54

Leaches ussually in fresh water
Many are predators but some are parasitic using blade like jaws to slit the skin and feed on blood. Produce anesthetic and an anticoagulant Hirudin to prevent clotting. Can be used in treatment of people.

Front 55

Nematodes

Back 55

These Round worms are nonsegmented and Pseudocoelomates and are found everywhere marine freshwater terrestrial living on plants and living in the body fluids of animals.
Many are important as decomposers but others are parasitic to animals and plants
Thrichinella spirals causes trichinosis.

Front 56

Arthropoda

Back 56

Most abundant organisms on earth.
Found in all environments and are most successful of all phylum.
Are segmented have an exoskeleton(made of chitin) and joints appendages.
Have open circulatory system.

Front 57

Advantages and disadvantages of exoskeleton.

Back 57

+Protection
+Atachment point for muscles
+Prevents desiccation retain moisture
+Allows Arthropods to colonize land as it can support itself out of a buoyant environment.

–Can't grow without shedding exoskeleton energy expensive
–when freshly molted are vulnerable

Front 58

Chelicerforms

Back 58

Named after claw like feeding appendage chelicerae

Front 59

Myriapoda

Back 59

Centipedes
Are carnivorous with using poison on prey and have one pair of legs per segment.(chilapoda)
millipedes eat decaying plant matter
And have 2 pair of legs per segment
(Diplopoda)

Front 60

Hexapoda

Back 60

Insects most abundant organism
One reason for success is flight
Can escape predators and find food and mates
Disperse to New habitats much faster than crawling or walking animals.

Front 61

Complete metamorphosis of Arthropods

Back 61

Egg hatches into a larva that looks entirely different than adult
Upon growing it will enter a pupa stage
The adult emerges and is specialized for dispersal and reproduction.

Front 62

Echinoderms

Back 62

They have water vascular system that branches into tube feet. Involved in locomotion feeding and gas exchange. Egg and sperm are released into the water for fertilization.
Larvae has lateral symmetry and adults have radial symmetry.