Developmental Bio 351 Exam 1 Questions and Answers 100% Pass

Developmental Bio 351 Exam 1 Questions and Answers 100% Pass Commitment - A cell's developmental state has been restricted (even though its not overtly displayed) Specification - first stage of commitment (reversible) cells can differentiate in a neutral environment determination - the second, irreversible step of commitment WILL BECOME DETERMINED CELL TYPE DESPITE ENVIRONMENT differentiation - the generation of specialized cell types from committed precursors what are the two types of specification? - autonomous specification conditional specification autonomous specification - cells achieve fate by factors received from parent cells without receiving external signals example: Progenitor trochoblast cells in snail Patella can be removed to a dish 2COPYRIGHT © 2025 BY SOPHIA BENNETT, ALL RIGHTS RESERVED • They will divide and then differentiate and make cilia in the correct developmental time conditional specification - cells achieve fate on factors/ interaction from surrounding cells can be signals, cell - cell contact, physical environment example: moving cells from back tissue to belly resulting in back cells expressing as belly cells what is the correct order of developmental steps differentiation, specification, determination - 1. specification mination rentiation At what stage do you find embryonic stem cells? - Blastula stage what are stem cells? - an undifferentiated cell of a multicellular organism that is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation. what are the two main characteristics of stem cells - ferentiated or unspecialized cells that can give rise to one or more specialized cells 2. capable of self renewal over long periods of time (division asymmetrically or symmetrically) 3COPYRIGHT © 2025 BY SOPHIA BENNETT, ALL RIGHTS RESERVED what is potency or potential? - The ability of a stem cell to differentiate into different cell types. asymmetric division - Single cell asymmetry - stem cell can self renew or commit Population asymmetry -stem cell becomes two committed cells -but when added with another stem cell can result in two new stem cells Adult stem cell lineage -multipotent stem cell can self renew or commit -committed cell can renew or turn into progenitor cell - which can then only turn into differentiated cells self renewal - process of giving rise to indefinitely more cells of the same cell type totipotent - capable of becoming any cell type (zygote) pluripotent - capable of becoming several cell types (ES cell from blastocyst) multipotent - capable of becoming more than one cell type 3 types of stem cells - Embryonic or ES cells Adult or somatic- undifferentiated cell, found among differentiated cells in a tissue or organ that can renew itself iPS or induced pluripotent stem cells- adult cells that have been genetically reprogrammed to an embryonic stem cell 4COPYRIGHT © 2025 BY SOPHIA BENNETT, ALL RIGHTS RESERVED Embryonic Stem Cells - pluripotent (can become several different cell types) Derived from inner cell mass of blastocyst cultured indefinitely in an undifferentiated state (committed but not differentiated) adult stem cell - Many organs contain monopotent or multipotent (more than one cell type) stem cells even in adults Give rise to limited set of adult tissue cell types • Often have a low proliferation rate, • Cells are difficult to isolate and identify example: satellite cell (muscle tear -- active proliferation) -bone marrow & homeopathic stem cells (Hsc) self renewal and can become B&T cells Pluripotent (iPS) stem cells - iPS cell comes from an ES cell originally but one can turn an adult somatic cell into an iPS cell and THEN reprogram it to create new cell types such as (mesoderm, endoderm, ectoderm) can be reprogrammed to cure human disease 5COPYRIGHT © 2025 BY SOPHIA BENNETT, ALL RIGHTS RESERVED how do you induce Pluripotent stem cells? - Induced pluripotent stem cells from expression of just 4 transcription factors in adult cells Pou5tf (Oct4) Myc (c-Myc oncogene) Klf4 (kruppel-like factor 4) Sox2 (SRY-box gene 2) These genes are also important in the development of the early blastocyte stage embryo. Endosteal niche interactions endosteal osteoblast secretes wnt signal binds to _______. interaction is important for __________. - Frizzled; Self renewal Endosteal niche interactions Angiopoietin-1 is secreted by endosteal osteoblast and binds to _______. interaction is important for ________. - Receptor Tie2 (RTK); maintaining potency Signaling between endosteal osteoblasts and hematopoietic stem cells (HSC) in the niche are necessary for which of the following? A. Differentiation of myeloid cells only. B. T and B cell differentiation 6COPYRIGHT © 2025 BY SOPHIA BENNETT, ALL RIGHTS RESERVED C. Maintenance of HSC potency and proliferation D. Angioblast specification - C. Maintenance of HSC potency and proliferation Which of the following statements is FALSE? a.Cell fates are reversible after specification. b.During autonomous specification, cells require communication with surrounding cells for commitment to a particular cell fate. c.Differentiation involves changes in gene expression, morphology, and function. d.Cell fates are irreversible after determination. - b.During autonomous specification, cells require communication with surrounding cells for commitment to a particular cell fate. in situ hybridization - detection of gene expression - provides temporal and spacial info by detecting mRNA Antisense mRNA complementary to specific mRNA -- antisense - binds specif