Cell Differentiation Flashcards
Sperm and egg come together to for a ____, a diploid cell.
Zygote
The zygote, then gives rise to a cluster of daughter cells called _____ which are transformed into Totipotent cells
Blastomeres
Three biological processes create the new individual:
Cell proliferation
Cell migration
Cell differentiation
The first observable event were cells begin to adopt different fates during embryogenesis, is the formation of the _____ and ___ ___ ___.
Trophoblast
Inner cell mass
Trophoblast cells will form the ____ membranes and most of the ____.
The inner sell mass cells will proliferate and differentiate to give rise to all of the cells of the ___.
Extraembryonic
Placenta
Body
The central mechanism by which cells adopt distinct fates during embryogenesis involves ____ ___ ____, where genes are turned off or kept active diverge
Differential gene expression
Cells that begin to pursue different fates do this by two general mechanisms: ___ ___ ___ and ____.
Asymmetric cell divisions
Induction
In asymmetric cell division, specific factors, such as mRNAs, and miRNAs are partitioned ____ among daughter cells during cell division. This process leads to a _____ pattern of development.
Unequally
Mosaic
In induction, cells are initially the same, but could be separately influenced by other cells, or other types of ___ ___. Cells are not ‘ born different’ but instead become different by receiving distinct signals. This leads to a _____ pattern of development, which is how most human development occurs.
Environmental signals
Regulative
Diagram of two mechanisms of differentiation:
Monozygotic or identical twins are produced from a ____ fertilized egg. This results when blastomeres exhibit reduced ____ and separate from each other. The later the separation occurs the greater risk for ____ ___.
Single
Adherence
Conjoined twins
The timing of blastomere separation determines whether separate ____ or ____ form, or whether they are shared or not.
Amnions
Chorions
The later, the separation, the more likely, the twins will share the same amnion and chorion. this is referred to as _____/____ pregnancies which is riskier because of the increased possibility of umbilical cords, becoming entangled
Monoamniotic/monochorionic (Mo-Mo)
Monozygotic twinning demonstrates that the fate of cells in the embryo are not determined until after the ____ ___ ___ and ____ ____ stages. This observation leads to the concept of ___ ___.
Inner cell mass
Early epiblast
Cell potency
The inner cell mass cells normally no longer produce trophoblast cells, and are therefore called _____.
Pluripotent
The epiblast forms all of the cells and body parts of the embryo an adult and are therefore also _____
Pluripotent
The process of ____ gives rise to the three basic germ layers, and now each a germ layer is a significantly more restricted in the types of cells and tissues they can form. Cells of each germ layer are referred to as ____.
Gastrulation
Multipotent
Review:
____ cells gain a general type of identification, such as neuromuscular, epidermal, etc. but the precise cell type is not yet defined
Committed
Commitment is usually followed by determination, and typically gives rise to a hierarchical pattern of organization. Early development is this characterized by a ___ ____ of cell fate.
Progressive restriction
Major signaling pathways involved in induction:
The ____ model (1950) of cell fate envisions that cells acquire specific fates as they roll down and enter different valleys
Waddington’s
Major early developmental cell differentiation events:
Diagram and summary of first decision:
Beyond specific cell fates: establishment of the body axes (dorsal/ventral, cranial/caudal, left/right)
Key points:
