Early Neuronal Development

Question 1

Why is asymmetry important in development?

Answer 1

Without asymmetry, there would be no way of getting different kinds of cells. There needs to be some heterogeneity and this is only possible through asymmetry

Question 2

Inductive signaling from one cell to another can occur in a gradient, why is this important?

Answer 2

Signaling from one cell to another can direct cells to a new developmental pathway

Question 3

What are the 5 essential processes by which an embryo is constructed

Answer 3

1. Cell Proliferation
2. Cell Specialization
3. Cell Interaction
4. Cell Movement
5. Cell Death

Question 4

Development proceeds from a ______ to a more ______ form.

Answer 4

1. general
2. specialized

Question 5

What is the universal mechanism of animal development?

Answer 5

Different species often use similar molecules to develop the organism

Question 6

Stages of development:

Answer 6

1. Blastula
2. Gastrula
3. Neurula

Question 7

During neurulation, the ectoderm has to decide its fate:

Answer 7

1. Epidermal
   or
2. Neural

Question 8

How does the neural tube and neural crest form?

Answer 8

1. The neural plate begins to change shape (think cytoskeleton)
   a. Microtubules cause the cells to become elongated and conical (columnar)
   b. Actin filaments cause contraction

Question 9

What is the difference between determination and differentiation?

Answer 9

• Determination: a cell is committed to a particular fate, but it does not yet exhibit any distinguishable features
• Differentiation: a cell expresses differentiated properties

Question 10

What happened when the animal cap of a pre-gastrula embryo was isolated and plated in culture? How was this different than the gastrula stage?

Answer 10

1. Cells became epidermal cells
2. However, when the cap was isolated during the gastrula stage the cells of the animal cap differentiated into neural cells