Exam 2: Development of a Body Pattern

In vertebrate nervous system development, what would happen to the neural tube if the notochord was removed? What would happen if a second notochord was transplanted to another part of the neural tube? What does this suggest about the function of the notochord?

As vertebrate development proceeds, the hindbrain becomes segmented into eight swellings called

If the anterior-posterior axis of the spinal cord is disrupted, what can you conclude happened in development?

In vertebrate nervous system development, what system is responsible for sharpening the homeobox gene expression boundaries between rhombomeres? How does this system work with respect to what the key players are, where they are located, how they interact, and how they influence gene expression and rhombomere boundaries? What does this mean for the fate of the cells that make up each rhombomere?

Describe the possible reasons why embryonic structure across species is so similar.

Which developmental signal is also a powerful teratogen?

Which is the first class of Drosophila regulatory genes to use cell-cell signaling across the membrane?

If scientists implant an acrylic bead infused with fibroblast growth factor into the middle of a developing chick embryo brain,

Refer to the graph. Where is the highest concentration of hunchback protein expressed in the Drosophila embryo, and how do the antagonistic actions of maternal polarity genes bicoid and nanos result in sharper boundaries of hunchback gene expression?

In normal vertebrate development, the hindbrain is distinguished from the forebrain and midbrain by the differential expression of

Ephrins are _______ that affect gene expression by _______.

Which class of genes directly influences the expression of pair-rule genes?

Refer to the figure. A normal wild-type mouse is shown in (A), a mutant mouse with enlarged rostral cortex centers is shown in (B), and a mutant mouse with enlarged caudal cortical centers is shown in (C). What specific mutations might (B) and (C) have?

In the evolution of the human brain there were four crucial steps; which event was the first?

The homeobox gene _______ is only expressed in the posterior portion of the midbrain and marks the boundary between midbrain and hindbrain.

What is a potential benefit of a random mutation that leads to a duplication in a gene?

Exposure to _______ prevents the posterior neural plate cells from becoming epithelial cells by making those cells _______ sensitive to BMP signaling.

If bicoid mRNA is injected into the middle of a bicoid-deficient Drosophila egg syncytium, the embryo will develop a

Which statement regarding homeobox and Hox genes is true?

Which class of genes initially establishes the anterior-posterior axis of the body plan?