Transcript Animal Cell

Phylogeny, Taxonomy, Cells
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 Eukarya
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Primates
Family Hominidae
Genus Homo
Species sapiens
Phylogeny of Kingdom Animalia
1 Parazoa
Eumetazoa
Bilateria
Radiata
2
3
Acoelomates
Coelomates
Pseudocoelomates
Protostomes
4
Segmented
Chordata
Annelida
Rotifera
(rotifers)
Porifera
(sponges)
Nematoda
(roundworms)
Segmented
Platyhelminthes
(flatworms)
5
Deuterostomes
Jointed appendages,
Exoskeleton
Notochord,
Pharyngeal arches,
Dorsal nerve
5 Segmentation
?
Protostome development
Deuterostome development,
Endoskeleton
Coelom
Pseudocoel
3
No body cavity
Radial symmetry
No true tissues
4
2
1
Multicellularity
Ancestral protist
Body cavity
Bilateral symmetry
Tissues
Two Types of Cells
• Prokaryotic
– Domains bacteria and archaea
• No nucleus or membranous organelles
• Typically small < 10m
• 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
DNA
Genes
Chromatin
Gene Expression
DNA
transcribed
RNA
translated
Protein
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
Bone
Cartilage
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.