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Bio 316 Exam 1 Study Guide | Questions And Answers Latest {2024- 2025} A+ Graded
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Homunculus - representation of a human being inside reproductive cells at start of development Preformation - debunked concept that an organism's reproductive cells CONTAIN microscopic versions of adults Epigenesis - theory of individual's final form is through a series of progressive changes How was preformation debunked? - use of microscopic studies of chick/egg development proved epigenesis Sperm and Egg cells are - single cells Stages of Embryogenesis - Fertilization, Zygote, Cleavage, Blastula, Gastrulation, Neurula (embryo) Organgenosis, Larval Stages(metamorphosis-some), Maturity Fertilization - fusion of sperm and oocyte (egg) Cleavage - cell division withOUT growth Gastrulation - 3 germ layers form (differentiation) Neurulation - neural tube forms Organogenesis - organs form Larval Stages - gonad development
Maturity - capable of reproduction (gametogenesis) LIfe Cycle of an Organism - Gamete - > Zygote - > Embryo - > Larvae - > Adult Cellular Life Cycle - ONE gamete - > join ONE zygote - > MANY cell embryos - > VERY many cell types Germ Line Concept Cell types - Reproductive cells (sperm and egg) and Somatic Cells (every other body cell) Heritable mutation rates and Germ Line Concept - rates are reliant on when and where the mutation occurs in germ line in either primordial cell or somatic cell Primordial Cell mutations - all gametes will have mutation Somatic Cell mutation - not affect germ line and will NOT be passed on Major Types of Cleavage - Holoblastic AND Meroblastic Holoblastic Cleavage (COMPLETE) types - Isolecithal and Mesolecithal Cleavage Isolecithal Cleavage - Sparse, evenly distributed yolk Isolecithal Cleavage types - Radial, Spiral, Bilateral, Rotational Mesolecithal Cleavage - moderate vegetal yolk disposition Mesolecithal Cleavage types - Displaced radial cleavage
Ventral - belly side Lateral - far from midline Medial - toward midline Anterior (Rostral) - front Posterior (Caudal) - Back Body Axes - Anterior, posterior, dorsal, ventral, lateral, medial Body planes - sagittal, horizontal, transverse Sagittal plane - left and right Horizontal plane - up and down transverse - cross section First body system to develop in verterbrate embryo is - nervous system Fate Map - determine where and what type of cells will be Types of Fate Maps - Vital dye, Fluorescent, Transgenic, Genetic Markers (Lineage) Vital Dye Stain - short lasting dye to alive cells to track
Fluorescent Dye Stain - long lasting and localized; needs special microscope that weakens dye each time used due to light exposure Transgenic DNA method - virus infected into gene to alter with another gene that encodes fluorescent protein development in infected cells Genetic Markers - transgenesis (using some factor present in a cell to another cell and seing if it'll grow) Von Baer's Laws - General features - > Specialized features - > Limbs/Bones appear - > All embryos share similar initial characteristics Embryonic Environment (EE) - conditions experienced that influence survival EE types - External, Internal, E.R.P (environmental regulation pathway) External environment - light, temp, humidity, predators Internal Environment - chemical (hormones, caffeine, nicotine) and competitors (litter-mates) Environmental Rregulation Pathway - external stimulator triggers signaling event in embryo that stimulates embryonic pathway and changes developmental pathway Differentiation - multi step specialization process preceded by commitment Commitment - involves specification and determination Specification - autonomous differentiation when placed in non-neutral ENVIRONMENT (reversible) Determination - autonomous differentiation when placed in a REGION (reversible)
