3.5.2 Morphogenesis

• Morphogenesis is the biological process responsible for shaping an organism during its development
• Order the four crucial components involved in morphogenesis

  1️⃣ Cell growth

  2️⃣ Cell differentiation

  3️⃣ Cell migration

  4️⃣ Programmed cell death
• What happens during cell growth in morphogenesis?

  Increase in size and number
• Cell differentiation in morphogenesis involves the specialization of cells into specific types
• The processes in morphogenesis are interconnected and coordinated.
• What is the term for programmed cell death in morphogenesis?

  Apoptosis
• Match the component of morphogenesis with its description:

  Cell Growth ↔️ Increase in size and number

  Cell Differentiation ↔️ Specialization into different cell types

  Cell Migration ↔️ Movement to correct locations

  Programmed Cell Death ↔️ Elimination of unwanted cells
• Cell movements are fundamental to morphogenesis, enabling cells to reach their designated locations
• What type of cell movement involves individual cells moving to new locations?

  Migration
• Cell sheets involve the movement of entire layers of cells together.
• Which cell movement elongates the structure by moving cells towards a central axis?

  Convergent extension
• Match the type of cell movement with its function:

  Migration ↔️ Colonizing different regions

  Cell Sheets ↔️ Forming layers of tissue

  Convergent Extension ↔️ Shaping the body axis

  Involution ↔️ Formation of germ layers

  Epiboly ↔️ Covering the embryo
• What drives cell differentiation in morphogenesis?

  Differential gene expression
• In muscle cell differentiation, proteins like myosin and actin are produced under the influence of growth factors
• Match the level of cell differentiation with its capability:

  Totipotency ↔️ Can form all cell types and a complete organism

  Pluripotency ↔️ Can differentiate into all cell types of the three germ layers

  Multipotency ↔️ Can differentiate into a limited range of cell types
• Growth factors and the extracellular matrix provide a supportive environment for cell differentiation.
• What are the two states of a gene during morphogenesis?

  Activated and repressed
• During limb development, Hox genes regulate the formation of limb structure
• What are the three major signaling pathways in morphogenesis?

  Wnt, Hedgehog, TGF-β
• Match the signaling pathway with its key components:

  Wnt Pathway ↔️ Wnt ligands, Frizzled receptors, β-catenin

  Hedgehog Pathway ↔️ Hedgehog ligands, Patched receptor, Smoothened protein

  TGF-β Pathway ↔️ TGF-β ligands, TGF-β receptors, SMAD proteins
• Wnt ligands bind to Frizzled receptors, activating β-catenin which promotes gene expression.