cmmb midterm(question n answers)graded A+ 2024/2025

cmmb midtermRTK pathway and FGFs - correct answer Ligand, RTK, GEF, RAS, RAF, MEK,ERK, TF, Transcription morula, blastula, gastrula blastomere - correct answer morula: cleavage stage embryo, no cavityblastula: cleavage stage, when there is a cavity in the embryogastrula: embryo undergoing gastrulationneurula: embryo as neural tube is formingblastomere: any cell of a cleavage stage embryo cleavage - correct answer rapid cell divisions divide the zygote cytoplasm into many smaller cells with no increase in volume metamorphosis - correct answer process controlled by thyroid hormones, changes in structure and limbs main cleavage patterns - correct answer holoblastic: entire egg is cleaved into cellsmeroblastic: only part of egg is cleaved into cells, inhibited by the yolkcentrolecithal: type of meroblastic cleavage where yolk centered in cell gastrulation - correct answer when three germ layers, ectoderm, mesoderm, and endoderm are formed and nervous system is induced the primitve streak forms around day 15 key outcome of gastrulation in chordates - correct answer formation of notochord, mesoderm structure, induces the nervous systemnotochord instructs ectoderm above to become nervous system, somites (mesoderm) on either side of notochord will form ribs, vertebrae, skeletal muscles 2 basic embryo cell types - correct answer 1. Epithelial cells: attached in a sheet2. Mesenchymal cells: individualized cells, can migrate can undergo EMT cell movement in gastrulation - correct answer - invagination: infolding of sheet/epithelium cells, sea urchin endoder- involution: inward movement of expanding outer layer that spreads over internal surface of remaining external cells, amphibian mesoderm- ingression: migration of individual cells to embryos interior, cells become mesenchymal, sea urchin mesoderm, drosophila neuroblasts- delamination: splitting of one cellualr sheet into 2+ parallel sheets, forms new epthilelial sheet of cells, hypoblast formation in birds/mammals- epiboly: movement of epithelial sheets spreading as a unit to enclose deeper layers of the embryo, ectoderm in sea urchin, turnicates, amphibians ectoderm, mesoderm, endoderm structures - correct answer ectoderm: nervous system, epidermal skin cellsmesoderm: notochord, bone tissue, RBC, tubule kidney cellsendoderm: stomach cell, thyroid cell, lung cell germ cells - correct answer precursors of sperm and egg, don't form from particular germ layer fate map, when can you find a fate map for an embryo - correct answer fate: cell's future path of differentiation in undisturbed embryo (under normal conditions), statistical likelihood - when fate depends on speciescells that form notochord occupy central/dorsalneural system precursors are anterior to itneural ectoderm surrounded by less dorsal ectoderm to form epidermis of skin stages of cell committment during development - correct answer specification - determination - differentiationpotency decreasesspecification: cell ocmmitted to fate, can still be reversed, differentiate along certain path unless signals or environment changes, restricteddetermination: committment to given fate is irreversible, cell will differentiate along path regardless of locationdifferentiation: developement into specialized cell type, cell is overtly a certain type at bchem and functional level cellular commitment definition - correct answer state in which a cell's developemental fate has become restricted even though it's not yet displaying overt changes in cell bchem and function cell fate 2 stages of specification - correct answer in neutral environment specification can be tested by isolating cells and culturing in a basic medium that has no effect on developmentdo cells differentiate to specific cell type? if so they are specifiedball of mixed cells, isolate/seperate two cell cultures, continues cell type specialization 2. cell fate, determination - correct answer when a cell can differentiate autonomously and its fate connot be reversed by neighbouring signals determined cell will develop autonomously in isolation but differs since commitment irreversible even in different environment- it will follow its determined path even if moved to another part of embryo harder to demonstrate determination than specification