BIO351 – MODULE 4 EXAM 4 QUESTIONS WITH
CORRECT ANSWERS
Mesodermal cells at the site of the limb buds respond to beads soaked in FGF8 and grow out along the
proximal-distal axis. If beads expressing FGF8 are placed under the epithelium of the back there is no
outgrowth. This experiment demonstrates which of the following?
- Permissive induction
- Proliferation
- Competence
- Gastrulation
- Differentiation - CORRECT ANSWER-✔✔✅- Competence
LEC 1.3 Slide 6
"Competence: a cell's ability to respond to an inductive signal."
Think about this: the soaked Fgf8 beads are transplanted 'under the epithelium of the BACK ... [and]
there is NO outgrowth."
Because there is no outgrowth when this is translated, this means the cells of the back are not
competent. Meaning, their signals are there/present from Fgf8, however, the cell's (of the back)
ability to comprehend and exact the goals of the Fgf8 signal is inadequate or incompetent.
textbook:
Cells of the responding tissue must have both a receptor protein for the inducing factor and the ability
to respond to the signal. The ability to receive and respond to a specific inductive signal is called
competence (Waddington 1940).
, Researchers were examining the role of SHH on patterning the digits in the limb bud. They predict a
gradient of SHH along the rostral/caudal axis is required to pattern the digits (left panel). Ablation of
the Zone of Polarizing Activity (ZPA) lead to the SHH concentrations in the right panel. Based on this
model, which pattern of digits (A-E) is expected.
-C
-D
-E
-A
- B - CORRECT ANSWER-✔✔✅- D
LEC 1.3 Slides 14, 17-18
As can be seen in the 'real' image (not depicted here), there are 2 thresholds for red, white, and blue
for particular digits.
The gradient depicted is a straight, horizontal line quite low on the morphogen gradient. Because of
this, red is the only color to be expressed.
Somites are derived from which of the following embryonic tissues?
- Endoderm
- Presomitic mesoderm
- Lateral plate mesoderm
- Ectoderm - CORRECT ANSWER-✔✔✅- Presomitic mesoderm
LEC 1.4 Slide 14
"Presomitic mesoderm generates somites-anlagen of the musculoskeletal system..."
CORRECT ANSWERS
Mesodermal cells at the site of the limb buds respond to beads soaked in FGF8 and grow out along the
proximal-distal axis. If beads expressing FGF8 are placed under the epithelium of the back there is no
outgrowth. This experiment demonstrates which of the following?
- Permissive induction
- Proliferation
- Competence
- Gastrulation
- Differentiation - CORRECT ANSWER-✔✔✅- Competence
LEC 1.3 Slide 6
"Competence: a cell's ability to respond to an inductive signal."
Think about this: the soaked Fgf8 beads are transplanted 'under the epithelium of the BACK ... [and]
there is NO outgrowth."
Because there is no outgrowth when this is translated, this means the cells of the back are not
competent. Meaning, their signals are there/present from Fgf8, however, the cell's (of the back)
ability to comprehend and exact the goals of the Fgf8 signal is inadequate or incompetent.
textbook:
Cells of the responding tissue must have both a receptor protein for the inducing factor and the ability
to respond to the signal. The ability to receive and respond to a specific inductive signal is called
competence (Waddington 1940).
, Researchers were examining the role of SHH on patterning the digits in the limb bud. They predict a
gradient of SHH along the rostral/caudal axis is required to pattern the digits (left panel). Ablation of
the Zone of Polarizing Activity (ZPA) lead to the SHH concentrations in the right panel. Based on this
model, which pattern of digits (A-E) is expected.
-C
-D
-E
-A
- B - CORRECT ANSWER-✔✔✅- D
LEC 1.3 Slides 14, 17-18
As can be seen in the 'real' image (not depicted here), there are 2 thresholds for red, white, and blue
for particular digits.
The gradient depicted is a straight, horizontal line quite low on the morphogen gradient. Because of
this, red is the only color to be expressed.
Somites are derived from which of the following embryonic tissues?
- Endoderm
- Presomitic mesoderm
- Lateral plate mesoderm
- Ectoderm - CORRECT ANSWER-✔✔✅- Presomitic mesoderm
LEC 1.4 Slide 14
"Presomitic mesoderm generates somites-anlagen of the musculoskeletal system..."
