Differentiation: a developing cell gains a particular role
הוצג| English | משמעות |
|---|---|
| differentiation/ˌdɪfəˌrenʃɪˈeɪʃn/ | התמיינות |
| repair/rɪˈpeə/ | תיקון |
What would explain this observation?
- A developing organism needs cells with different tasks. Producing more cells is not the same as making those cells become specialized.
Build the model
- Differentiation 分化 is the process by which a cell becomes specialized.
- As it develops, the cell acquires particular sub-cellular structures suited to its function.
- Most types of animal cell differentiate early in development.
- Many plant cells retain the ability to differentiate throughout life.
- differentiation: The process by which a cell becomes specialized.
- repair 修复: Restoration of damaged tissue through appropriate cellular processes.
What distinguishes differentiation from mitosis?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
Differentiation changes what a cell is - its structures and role - while mitosis changes how many cells there are. Differentiation removes no genetic material; the genome stays complete.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- In a mature animal, cell division mainly supports repair and replacement.
- Differentiation and mitosis have different roles: division increases cell number, while differentiation changes the functional type.
- Cells in a growing root can continue producing new plant tissues because developing cells can still specialize.
In the lab: Use a model lineage that distinguishes division arrows from differentiation arrows. Label an undifferentiated starting cell, the increase in number, and the later cell functions. Compare plants and animals without claiming that no adult animal cell can divide or that every adult cell can form every tissue.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: one model precursor divides into two, then each divides once more, giving four cells.
- If two become one tissue type and two another, cell number remains four during the stated specialization step.
- Four cells were produced by division; the later differences are explained by differentiation.
Your turn: One precursor completes three rounds of model division before differentiation. How many cells result?
One precursor completes three rounds of model division before differentiation. How many cells result?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 8 cells. Known: one precursor; three rounds of division, each doubling the cells. Final number = 1 x 2^3 = 8 cells. Differentiation afterwards changes their roles, not their number.
Check the conclusion and its limits
- Differentiation does not mean a cell simply gets larger, and it does not usually mean the cell receives a completely new genome.
- Mature animal repair still depends on some cells dividing, even though most differentiated cells have restricted roles.
Not true: Differentiation always doubles cell number. Differentiation assigns roles; division produces cells. One cell differentiating is still one cell - numbers change only through division.
- Differentiation is the process by which a cell becomes specialized.
- In a mature animal, cell division mainly supports repair and replacement.
- Watch for: differentiation does not mean a cell simply gets larger, and it does not usually mean the cell receives a completely new genome.
Differentiation always doubles cell number.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
Differentiation assigns roles; division produces cells. One cell differentiating is still one cell - numbers change only through division.
The process by which a cell becomes specialized: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
differentiation means The process by which a cell becomes specialized.