Presentation on theme: "Do Now Download Development Honors Notes off of my website"— Presentation transcript:
1 Do Now Download Development Honors Notes off of my website Where’s my money?!?!?!Hand in Meiosis Pictures Lab
2 Something to think about as your open up your notes Humans have approx trillion cells and these cells are all different types (hair, skin, liver, stomach cells, etc.).How can you explain all these types of cells if humans only start as a single cell?
4 EmbryologyThe study of theEmbryoAn organism in the
5 IMPORTANT! RECOMBINATION Sperm = DNA (haploid) : one version of each type of chromosome.Egg = DNA (haploid): same as aboveThe combination of one sperm with one egg will unite and make .If another sperm or another egg unite, a human would result.
9 Oogenesis Unequal meiotic divisions unequal distribution of cytoplasm What is the advantage of this development system?OogenesisUnequal meiotic divisionsunequal distribution of cytoplasmeggpolar bodiesMeiosis 1 completedduring egg maturationovulationMeiosis 2 completedtriggered by fertilizationPut all your egg in one basket!
12 1) Cleavage Repeated of zygote 1st step to becoming cellular unequal divisions establishes body plandifferent cells receive different portions of egg cytoplasm & therefore different regulatory signals
13 Cleavage zygote m b establishes future development blastula zygote gastrulationmorulablastula
14 2) Gastrulation Establish 3 cell layers E M gastrulation in primitive chordates2) GastrulationEstablish 3 cell layersEouter body tissuesskin, nails, teethnerves, eyes, lining of mouthMmiddle tissuesblood & lymph, bone & notochord, muscleexcretory & reproductive systemsinner liningdigestive systemlining of respiratory, excretory & reproductive systemsectodermmesodermendodermprotostome vs. deuterostome
15 Testing…In a study of the development of frogs, groups of cells in the germ layers of several embryos in the early gastrula stage were stained with five different dyes that do not harm living tissue. After organogenesis (organ formation), the location of the dyes was noted, as shown in the table below.Tissue StainBrain RedNotochord YellowLiver GreenLens of the eye BlueLining of the digestive tract Purple
16 Neurulation Formation of notochord & neural tube develop into system develops into CNS (brain & spinal cord)Neural tubeNotochorddevelops into vertebral column
20 Testing…All of the following correctly describe the fate of the embryonic layers of a vertebrate EXCEPTA. neural tube and epidermis develop from ectodermB. linings of digestive organs and lungs develop from endodermC. notochord and kidneys develop from endodermD. skeletal muscles and heart develop from mesodermE. reproductive organs and blood vessels develop from mesoderm
23 3. Growth and Differentiation As embryo develops, the # of cells continues toDifferentiationcells becomeDifferent sections of DNA are , some are turned .Certain cells act as organizersThese cells influence other cells to become certain cells, tissues
24 STEM CELLS Omnipotent = have the potential to be type of cell. If mitosis is done, all cells are identical.FACT: all of your cells contain the (because of mitosis)
25 HOW DO WE GET DIFFERENT CELLS? Differentiation: some DNA is turned off and only some directions are read, for example:Skin cells: all DNA directions are turned off, except for how to make skin.