BIOL 3454 1nd EditionExam # 2 Study Guide Lectures: 11-15Lecture 11 (September 17)I. Chapter 8 Principles of development a. Hans Spemann and Hidle Mangold i. Tissue induction using salamander embryosii. Dorsal lip from salamander gastrula, implant it on a host salamander then will get a new salamanderII. Developmental biology a. Single cell becomes a multicellular organism b. Developmental biology fell behind – fusion of genetics, evolution, functional molecular biology has closed the gap of understanding III. Historical ideasa. Preformation – the entire organism was in a miniaturized version w/in a sperm or eggb. Epigenesis – origin upon or after; an egg contains building material, activated by spermc. Hierarchy of developmental decisions – cellular # and diversity arises sequentiallyd. A cell which has committed to a fate it is determined by one of two processes i. Specification ii. Induction – usually irreversibleIV. Oocyte maturation a. Morphogenetic derminants – transcription and inducing factors, direct activation and repress genes at the correct times b. At times fertilization occurs before the oocyte has undergone meiosisc. Prophase I – GVBD – metaphase I – metaphase II – pronucleusV. Fertilizationa. Male & female gametes unite to form zygote – combo restores diploid chromosomal status b. Timing of fertilization is highly veriable among organisms with regard to oocyte maturity c. Sperm not always required for egg activationd. Contact between egg and spermi. Species specific recognition proteins ii. Prevent fertilization by another species iii. Postmating prezygotic isolating mechanism iv. Esp useful for gametes in watere. Contact and prevention of polyspermy i. -n+n=2n / n+n+n….. =Xn (not good)f. Fast block – electrical potential charge change in the egg membrane g. Slow block – cortical rxn, thousands of enzyme capsules release their contents between the egg membrane and vitellene envelopeh. Creates an osmotic water rushes in sperm washed away. Later causes the vitellene membrane to harden and physically block spermVI. Sea urchin fertilizationa. Easy to find cheapb. Fertilization external easy in labc. Embryo transparent easy to see development d. Very historic, Aristotle VII. Cleavage and early development a. Blastomeres – small maneuverable cells b. No growth just a big mass dividing to a group of normally sized cells c. Polarity established (animal pole & vegetal pole)Lecture 12 (September 19)I. Yolk distributiona. Isolecithal – very little yolk, evenly distributedb. Mesolicithal – moderate amount of yolk at vegetal pole c. Telolecithal – lots of yolk at vegetal pole d. Centrolecithal – large centrally located yolkII. Cleavagea. Meroblastic – lots of yolks cells sitting on top of undivided yolkb. Holoblastic – cleavage furrows extend completely though the eggIII. Direct vs indirect development a. Direct development – embryo to a miniature adultb. Indirect development – multiple developmental stagesc. Either can be shortcut by matrotrophy where the mother nourishes the developing embryoIV. Development following cleavagea. Blastula – cluster of cells, usually hollow, space is the blastocoel, one layer of germ cells (one tissue layer)V. Gastrulation & the formation of two germ layersa. Gastrulation – the conversion of the spherical blastula into a two or three layered embryob. Archenteron – the internal pouch formed in gastrulation c. Blastopore – the opening to the archenteron VI. Developmental layers a. Three primary germ cell layers: triploblastic i. Ectoderm – most exterior becomes integument & nervous system ii. Endoderm – most of the GI tract, most of the internal organsiii. Mesoderm – most connective tissues, fluids and muscles VII. Development of Ectoderm a. Nervous system b. Thickens to form neural plate above notochord to form neural platec. Nerve cells grow & develop by cues external to the cell like a road mapVIII. Development of endoderm a. Digestive systemb. Alimentary canal emerges from te primitive gutc. Lungs liver pancreas all emerge from the gutd. Gill arches & their derivative (jaw & ears) emerge from endodermIX. Development of mesoderma. Forms musclesb. Repeated segments of somites c. Muscular organs like heartLecture 13 (September 22)Chapter 9I. Animal architecture II. Hermit crabs – steal/find own shellIII. Grades of organisms complexity a. Protoplasmic – unicellular organisms, protoplasm divided into organelles b. Cellular – division of labor among aggregated cells that are functionally different c. Cell tissue – aggregations of similar cells into patterns or layers specialized for a commonfunctiond. Tissue organ – tissues combined with other types of tissue to form a structure with a more complex function than a single tissue e. Organ system – organs working together for a common higher function across the spatialand temporal dimensions of the organism IV. Phylogenetic constraint a. Where you start has a great effect on where you finish b. Animal body plans are phylogenetically constrained i. Binolcular vision b/c primate ancestors swung through trees & needed depth perception c. Major examples in animalsi. Symmetryii. Number of germ layersiii. Number of body cavities d. Symmetry i. Spherical –c ut any way & will always be mirror imagines ii. Radial – 2 similar halves longitudinal axis iii. Front is different than back iv. Biradiale. Its good to be radial if environment meets needs on all sides f. Optimize shape to move = bilateral V. Coelems a. Coel – any hollow or open spaceb. Aceoelmatec. Pseudoceolomated. CoelomateVI. Extracellular componentVII. Epithelial tissues a. Covers outside of body b. Tight junctions c. Basal side attached d. Simple = 1 layere. Cuboidal = cubed shaped f. Columnar = g. Pseudo stratified ciliated columnar – mucus membranesh. Simple squamous – diffusion i. Stratified squamous – durable j. Transifional – stretching VIII. Connective tissuea. 6 types of connective tissuei. Loose connective tissue ii. Cartilageiii. fibrous connectiveiv. Adipose v. Blood vi. Bone b. 3 types of connective tissue fiberi. Catagenous fibersii. Elastic fibersc. 2 major cell types found in connective tissue i. Fiberblastsii. Macrophagesd. Older you get the less cartilage – wears down chondrocytes – chonderoitin sulfate – cushion between disk jointse. Adipose – few cells ; when get big add fat to a cell don’t increase of decrease # of cells f.