BIO 302 Study Guide - Midterm Guide: Morphogen, Blastomere, Organogenesis
Differential Gene Expression: process by which different types of cell arise, leading to cells
with specific structures and functions.Multiple proteins interact to determine developmental
programmed cell death (apoptosis), morphogen gradients provide positional information.
Stages of Development:
Oocyte -> cleavage -> blastula(hollow ball of cells) -> Gastrulation -> Organogenesis
Cleavage: After fertilization, the sperm and egg become a zygote, which then begins a number
of cell divisions called ‘cleavage’
Blastulation: blastulation is initiated during early cleavage stages, and formation of the
definitive blastula is thought to terminate cleavage and to initiate gastrulation; formation of a
cavity
Gastrulation: The three germ layers—ectoderm, mesoderm, and endoderm—form.
• Ectoderm - Outermost layer, epidermis, nerve tissue
• Mesoderm- Middle layer, notochord, muscles, skeleton, circulatory system
• Endoderm- Innermost layer, liver, pancreas, lungs, lining of digestive tract
Organogenesis: when individual organs develop within the newly formed germ layers.
Cell Labeling: Mark cells with fluorescent dye/staining and watch development
Fate Mapping: A territorial diagram of embryonic development that displays the future
derivatives of individual cells and tissues ( fluorescent peptide tracers )
Autonomous Specification:certain regions of egg cytoplasm contain specific morphogenetic
determinants. As cell cleaves, determinants end up in different blastomeres. An isolated
blastomere will then become the type of cell dictated by the determinant in it (its original location
w/in egg)
Conditional Specification: Cells are programmed by the local conditions around them, if cell is
removed surviving cells can be altered to replace it; this regulatory development is characteristic
of vertebrates
Morphogen: Substance that governs tissue development (protein or mRNA)
Trans. Factor: A protein that binds to specific DNA sequences, thereby controlling the rate of
transcription of genetic information from DNA to messenger RNA.
Cell-Cell Signaling: Cells have proteins called receptors that bind to signaling molecules and
initiate a physiological response.
Fertilization:
• Sperm-Egg Attraction: Chemo attraction ( soluble molecules secreted by egg)
• Blocks to Polyspermy:
o Slow:The formation of the fertilization envelope and other changes in an egg's
surface that prevent fusion of the egg with more than one sperm. The slow block
begins about 1 minute after fertilization
o Fast: The depolarization of the egg plasma membrane that begins within 1 to 3
seconds after a sperm binds to an egg membrane protein. The depolarization
lasts about 1 minute and prevents additional sperm from fusing with the egg
during that time
• Ca++ signaling:
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Differential gene expression: process by which different types of cell arise, leading to cells with specific structures and functions. multiple proteins interact to determine developmental programmed cell death (apoptosis), morphogen gradients provide positional information. Oocyte -> cleavage -> blastula(hollow ball of cells) -> gastrulation -> organogenesis. Cleavage: after fertilization, the sperm and egg become a zygote, which then begins a number of cell divisions called cleavage". Blastulation: blastulation is initiated during early cleavage stages, and formation of the definitive blastula is thought to terminate cleavage and to initiate gastrulation; formation of a cavity. Gastrulation: the three germ layers ectoderm, mesoderm, and endoderm form: ectoderm - outermost layer, epidermis, nerve tissue, mesoderm- middle layer, notochord, muscles, skeleton, circulatory system, endoderm- innermost layer, liver, pancreas, lungs, lining of digestive tract. Organogenesis: when individual organs develop within the newly formed germ layers. Cell labeling: mark cells with fluorescent dye/staining and watch development.
