Embryogenesis Flashcards
What is the difference between Preformationism and Epigenetic in theory
People who believed in preformationism thought that an origin of organisms development and growth were predeterminded only by its genetic material whereas epigenetic believes that an organisms development is shaped by the interaction of genes with environmental factors
What are the different steps in embryogenesis
- Fertilization
- Cleavage
- Gastrulation
- Organogenesis
During cleavage, will the cell become bigger?
No, the cleavaged cell will not become bigger. The cleavage forms blastomeres, and after genome activation, the blastomere will form into a blastocyte what will implant in the uterus lining
What are the differences of mitosis and meiosis
- Purpose: Mitosis is used for asexual reproduction, cell growth and tissue repair whereas meiosis is used for sexual production
- Number of daughter cells: Mitosis gets 2 identical daughter cells with the same number of chromosomes whereas meiosis gets 4 non identical cells with half the number of chromosomes
- Chromosome replication: Mitosis replicated once before cell division whereas meiosis replicates twice: once before first meotic division and once before the second meotic division
- Chromosome distribution: Mitosis distributes them equally to the daughter cells whereas meiosis distributes them randomly so there is genetic diversity
- Stages: Mitosis: Prophase, Metaphase, Anaphase, Telophase (PMAT)
Meiosis: PI II, MI II, AI II, TI II, Cytokinesis I II
What is the symmetry breakage after fertilization
After entry of the spermcell, the fertilized cell loses symmetry. The cell figures out what’s going to be the front and the back of the organism already.
Where the sperm enters: proteins are remoddeled (ex. the ECM).
What cells contains a blastocyst
The Inner Cell Mass (ICM) which are pluripotent stem cells and the thropoblast (will form placenta)
What regulates the cells to become ICM or Trophoblasts?
Position of the blastomeres (On top or in the middle of the cell) and signaling of the cells.
Cells that are lining external in the blastomere are usually going to be part of the trophoblast whereas internal cells will develiop into ICM
Name the difference in Hippo pathway ON/OFF and name their outcome
Hippo pathway OFF:
- Yap is in the nucleus
- Oct4 is not expressed
Blastomere becomes trophoblast
Hippo pathway ON:
- Yap retains in cytoplasma
- Oct4 is expressed
Blastomere becomes ICM
So the Hippo pathway regulates ICM/Trophoblast cell fate
In what state will the firtilized zygote implant in the uterus lining?
Blastocyst
What cells contains the Gastrula (so during gastrulation)
- Ectoderm: will give rise to epidermal, central nervous system and neural crest (outerlayer of the Gastrula)
- Endoderm: will give rise to gut tube, appendages: lung, pancreas, liver (Internal layer of Gastrula)
- Mesoderm: will give rise to muscle, connective tissue, blood, kidney (middle layer of Gastrula)
What is the role of hippo pathway in cancer?
the Hippo pathway is crucial for maintaining tissue homeostasis and preventing cancer by controlling cell proliferation, apoptosis, and organ size. Dysregulation of this pathway can lead to the development and progression of cancer by promoting cell growth, invasion, survival, and chemoresistance.
What is Neurulation
The process of formulation of the neural plate (by ectoderm cells) and neural crest. During this, a group of cells from ectoderm undergo EMT and form the neural crest cells
What is EMT
Epithelial to Mesenchymal Transition. This is a process in which epithelial cells lose their cell-cell adhesion and polarity + acquire a Mesenchymal phenotype, characterized by increased mobility + the ability to invade surrounding tissue. This is key event for formation Mesoderm
What is Organogenesis
Process of forming/developing organs in a developing organism. It involves the formation of specific tissues and the differentiation of cells into specific cell types, leading to the formation of functional organs
