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 < 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 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.