Bio IIRupp

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VERTEBRATE—ANY ANIMAL WITH A BACKBONE

INVERTEBRATE—ANY ANIMAL WITHOUT A BACKBONE

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50 trillion cells in the human body

Cells need eachother and specialize

Cell junctions—connections between cells—allow tissue formation and communication

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Ingestion of food Breakdown of food

to release molecules essential to life

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Diploid zygote—first cell of a new individual (ploidy number)

Differentiation Specialization

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Ability to move comes from the unique relationship of two tissue types• Muscle• Nerve (neurons)

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First animals probably arose from the sea

Loosely connected flagellated protists

Division in labor allowed multicellularity

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Oparin’s theory on Early Earth

Miller-Urey Experiment

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Symmetry—a consistent overall pattern of structure

Simple organisms lack symmetry Patterns of symmetry

• Nonsymmetrical• Radial symmetry• Bilateral symmetry

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Cephalization Germ layers—

fundamental tissue types found in embryos of animals except sponges

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Similarities in structure allow biologists to classify—morphology• Multicellular, limited cell specialization =

sponges• Tissues in two layers = cnidarians and

ctenophores• Tissues in three layers and bilaterally

symmetrical = all other phyla from figure 34-5 page 672

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Invertebrates Chordates

• Notochord• Postanal tail• Pharyngeal gill pouches or slits• Dorsal, hollow nerve cord

Vertebrates

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Invertebrates Vertebrates

Symmetry Radial or bilateral --

Integument -- Usually to hold water in; specific functions

Segmentation Repeating subunits Ribs and vertebrae

Support of the body Exoskeleton Endoskeleton

Respiratory Gills Lungs

Circulatory Open Closed

Digestive/Excretory Gut or digestive tract Gut or digestive tract as well as filters like kidneys

Nervous Extraordinary diversity Highly organized brains and nervous systems

Reproduction/Development

Sexual and asexual, hermaphroditic, indirect development

Eggs released to water, eggs held internally, development internal or external, typically direct development

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SPERM EGG OR OVUM

Small Motile Head contains

chromosomes Tail is a flagellum

Large Cytoplasm and yolk Yolk size depends on

development length; longer development = big yolk

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Sperm membrane joins with egg membrane and sperm nucleus enters the egg cytoplasm

Sperm entry causes an electrical reaction to block more sperm from entering

Nuclei of sperm and egg merge to form a diploid zygote

DNA replication and mitotic division begins

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PREFORMATION EPIGENESIS

Organisms were preformed inside the egg or sperm

The organism in the egg or sperm needed only to unfold

Some claimed to see the organisms in sperm

Kasper Friedrich Wolff Said eggs do not contain

preformed organisms only the raw material to form organisms

Materials need to be activated

Basis for how things actually work

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Restores diploid number

Activates egg to develop

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Cleavage—divisions of the zygote

Exponential increase Cells get smaller with

each division As division occurs the

cells form a hollow ball called a blastula

Empty space in the blastula is the blastocoel

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Stage of development that follows blastula

Blastula indents or invaginates and the region becomes known as the blastopore

Invagination leads to a multilayered embryo

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Archenteron• Deep cavity of the gastrula• Becomes the gut• Throat, gills, lungs , liver, pancreas

Ectoderm• Outer layer• Skin, hair, nails, nervous system

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Endoderm• Inner layer• Epithelial lining of gut

Mesoderm• Middle layer• Skeleton, muscles, circulatory system

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Coelom—a body cavity lined with a mesoderm

Development can be based upon how the coelom forms, aka, patterns of cleavage

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PROTOSTOMES DEUTEROSTOMES

Blastopore forms the mouth

Mouth forms first Anus forms second Spiral cleavage

Blastopore forms anus Anus forms first Mouth forms second Radial cleavage

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DETERMINATE CLEAVAGE INDETERMINATE CLEAVAGE

The fate of the cells is determined at an early developmental stage

Separation of the zygote at the 4-cell stage results in cell death

The future of each cell is determined

The fate of each cell is not determined at an early developmental stage

Cells can be separated and survive (cloning)

The future of each cell is not determined

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SCHIZOCOELY ENTEROCOELY

Split body cavity Endoderm/ectoderm

junction cells divide to form mesoderm

Mesoderm is separated by the blastopore

Gut body cavity Cells that form the

archenteron begin to divided to form the mesoderm

“Mickey Mouse Ears”

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Acoelomate• No body cavity• Ectoderm and endoderm are connected by

mesoderm Pseudocoelomate

• False body cavity• Mesoderm lines the ectoderm• Gut is suspended in body fluid

Coelomate• True body cavity• Mesoderm provides support to ectoderm and

endodermic gut

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