Phylogeny, Taxonomy, Phylogeny, Taxonomy, Cells and TissuesCells and Tissues

Phylogeny, Taxonomy, Phylogeny, Taxonomy, Cells and TissuesCells and Tissues

Phylogeny & Taxonomy

• Phylogeny– Evolutionary relationship of animal groups– Established by comparative study of homologies

• Anatomical• Embryological• Molecular

• Taxonomy– Naming of groups– Based on phylogenic relationships and

homologies at Domain, Kingdom, Phylum level– Based on individual traits at Genus & species level

Taxonomic Groups

Domain

Kingdom Phylum

Class

Order

Family

Genus

Species

• Archae, Bacteria, Eukarya• Animalia, Plantae, Protista,

Fungi• 11 major & 9 minor phyla of

Animalia

• Genus species binomial nomenclature used to specifically identify organisms

Taxonomy of Humans

Domain EukaryaKingdom Animalia

Phylum Chordata

Class Mammalia

Order Primates

Family Hominidae

Genus Homo

Species sapiens

Phylogeny of Kingdom Animalia

Protostomes Deuterostomes4

Deuterostome development,EndoskeletonProtostome development 4

Mo

ll us c

a

5

Tissues1

Parazoa Eumetazoa1

No true tissues

Po

rife

ra(s

po

ng

es)

Radiata Bilateria2

Bilateral symmetryRadial symmetry 2

Rad

iat a

(C

nid

aria

and

Ct e

no

ph

ora

)Acoelomates Pseudocoelomates Coelomates3

Body cavityNo body cavity 3

Pla

tyh

elm

inth

es(f

latw

orm

s)

CoelomPseudocoel

Nem

ato

da

(ro

un

dw

orm

s)

Ro

tife

ra(r

oti

fers

)?

Lo

ph

op

ho

rate

s

Jointed appendages,Exoskeleton

Segmentation

Segmented

5

An

nel

ida

Ar t

hr o

-p

od

a

Segmented

Notochord,Pharyngeal arches, Dorsal nerveE

chin

od

erm

ata

Ch

ord

ata

Ancestral protist

Multicellularity

Two Types of Cells

• Prokaryotic– Domains bacteria and archaea

• No nucleus or membranous organelles• Typically small < 10m• Single circular chromosome

• Eukaryotic– Domain eukarya

• Have a nucleus (sometimes more than 1)• Have numerous membranous organelles• Larger than 20 m (usually >100 m)• Multiple, linear chromosomes within nucleus

Animal Cell

Nucleus• Houses chromosomes - DNA• Transcription – production of RNA from DNA• Key components

– Nuclear membrane– Nucleoplasm– Chromatin threads– Nucleolus

Nucleus

Gene Expression

DNA

transcribed

RNA

translated

Protein

DNA Genes Chromatin Chromosomes

Chromosome

• Each chromatid is a DNA double helix

• Aggregate of genes

Sister

Mitosis

Cell Membrane

• Encloses cell

• Regulates entry/exit of materials

Endoplasmic Reticulum

• Ribosomes – protein synthesis

• ER – processing of proteins

Golgi Apparatus

• Processing of proteins for secretion

Production & Secretion of Proteins

Mitochondrion

• Production of ATP

• ATP used to activate proteins

Cellular Organization

• Cells

• Tissues – similar cells are organized to perform common functions.

• Organs – tissues are assembled organs which perform specific functions

• Animal

Major Tissue Types

Muscle Tissue

• 3 major types– Cardiac– Skeletal (striated)– Smooth

• Major proteins– Contractile proteins

• Actin• Myosin

Muscle Tissue: Skeletal

• Multinucleated cells • Attached to bones

• Main function is movement

Muscle Tissue: Cardiac

• Striations, but unfused cells

• Located in heart• Function is

contraction the heart

Muscle Tissue: Smooth• Mononucleate• Located in GI tract, uterus, urinary bladder and

blood vessels.• Propulsion of materials

Connective Tissues

• Adipose – support, protection, conservation of heat and energy storage.

• Areolar – anchors blood vessels, nerves and organs.• Cartilage – flexibility and support• Bone – protection, support and muscle attachment• Blood – transport oxygen / CO2, clotting and immune

response

• Extracellular matrix– Collagen – forms cable-like fibers or sheets that provide tensile

strength.– Elastin – rubber like protein fiber that abundant in flexible

tissues.– Fibronection – promotes cell adhesion and anchorage.

Connective Tissue: Areolar

Connective Tissue: Adipose

Connective Tissues: Cartilage & Bone

Cartilage

Bone

Connective Tissue: Blood

• Erythrocytes – red blood cells

• Leukocytes – white blood cells

• Platelets

Epithelial Tissue

• Tightly connected cells

• Line exterior of body

• Line interior of cavities– Gut, blood vessels, lymph vessels, glands

• Secretion– Sweat– Digestive enzymes– Milk

Epithelial Tissues

Neural Tissue

• Composed of highly specialized cells called neurons that transmit electrical impulses across junction called synapses.

• Total number is fixed at birth.