20: Cellular Mechanisms of Animal Development Flashcards
Module 4, Lesson 3
The process by which a single-cell fertilized egg becomes a fully-formed adult is called…
Development
Development is regulated by…
Changes in gene expression over time
List the four major processes in development.
- Cell division
- Differentiation
- Pattern formation
- Morphogenesis
Which two developmental processes continue into adulthood?
Cell division and differentiation
Scientists often use ____ to study development.
Model organisms
List two benefits of using model organisms in developmental research.
- They are usually less complex
- They avoid ethical concerns surrounding manipulation of human embryos
C. elegans, a species of roundworm, is a model organism often used to study…
Cell division and differentiation
A ____ shows all cell divisions over an organism’s lifetime, describing the fate of each cell in the body.
Cell lineage map
Through studies on C. elegans, scientists learned about…
Cell division and how cells are assigned a particular fate
Fruit flies are a model organism used to study…
Pattern formation in embryos
Studies on fruit flies demonstrated that…
Development is driven by changes in gene expression
African clawed frogs are a model organism used to study…
Cell division and morphogenesis
Why were African clawed frogs ideal for studying morphogenesis?
They undergo a change from tadpole to adult
The most obvious developmental process is…
Cell division
During development, ____ transfroms a unicellular zygote into a multicellular organism.
Cell division
At what point in an organism’s lifetime does cell division occur the fastest?
Early embryonic stage
How is the early embryonic cell cycle different from the regular cell cycle?
(three)
- Only inclues S and M phases
- No cell growth occurs between divisions
- No G1 or G2 phases
The purpose of early embryonic cell division is to…
Split the zygote’s cytoplasm into smaller volumes
The early embryonic cell cycle is also called…
“Cell cleavage”
How does the later embryonic cell cycle differ from the early embryonic cell cycle?
(three)
- The cell cycle becomes longer
- Cell growth occurs
- Includes G1 and G2 phases
The production of specialized cells is called…
Differentiation
Differentiated cells arise from the division of undifferentiated…
Stem cells
Any cell which has not adopted a particular cell fate is a…
Stem cell
What happens to the daughter cells produced by stem cells when they divide?
- One cell gives rise to differentiated cells
- One cell replaces the original stem cell
The process by which the original stem cell is replaced by one of its daughter cells is called…
Self-renewal
Over time, differentiation causes gene expression to be…
Gradually altered
True or false:
Over time, the number of fates that a cell descended from a stem cell can adopt is restricted.
True
Differentiation occurs over ____ cell division(s).
Multiple
Stem cells are categorized by their…
Potency
A stem cell’s ____ represents the range of possible cell fates that the descendant cells may have.
Potency
List the four levels of stem cell potency.
- Totipotent
- Pluripotent
- Multipotent
- Unipotent
A(n) ____ stem cell can form all tissues in an organism, including those needed for embryonic development.
Totipotent
True or false:
A single totipotent stem cell can develop into a complete organism.
True
List two examples of totipotent stem cells.
- The zygote
- Blastomeres
____ are cells that result from the first few divisions of the zygote.
Blastomeres
A(n) ____ stem cell can form all tissues in an organism except those needed for embryonic development.
Pluripotent
True or false:
A single pluripotent stem cell can develop into a complete organism.
False
It has the potential to do so, but cannot form the tissues needed to support an embryo