Exam 20: Genes and Development

The question of whether animal eyes have evolved independently in different organisms or have evolved once from a single organism and then diverged over time is still being actively investigated by scientists.

Maternal-effect genes:

Which of the following statements is TRUE regarding ligand-receptor pairs?

Maternal-effect genes code for _____ present in the egg.

Maternal-effect genes:

Several genes involved in the early stages of development are conserved across many types of organisms.

Stem cells are cells that are capable of:

Many valuable horticultural varieties of plants, including roses, rhododendrons, junipers, geraniums, and so on, are commonly propagated by inducing roots to form on cuttings taken from branch tips. This method involves cutting a few inches from the tip of a branch and inserting the cut end into moist sand or other substrate. Under the right conditions, roots may form from the cut end, giving a new plant generated from the stem cutting. In what way could this phenomenon be used to argue for or against the "genome reduction" hypothesis for cell differentiation?

Signal transduction is mediated by _____ interaction.

Human development begins with fertilization, but the fertilized egg does not begin to divide until after it implants in the uterine wall.

Individual cells in the human blastocyst begin to grow at each cell division after:

Which of the following statements is TRUE regarding AP3 and PI (the protein products of APETALA-3 and PISTILLATA, respectively)?

In the graph shown here, the dashed line shows the level of mRNA for a certain protein, Prot1, at various positions along the anterior-posterior axis of an insect embryo. The solid lines portray the levels of two regulatory proteins, A and B, that control translation of the Prot1 mRNA. If both A and B repress translation of the Prot1 mRNA, then which graph BEST approximates the expected level of Prot1 across the embryo?

Which of the following statements is TRUE regarding C. elegans?

Which of the following are multipotent cell types?

Regenerative medicine is a field that aims to use the natural processes of cell growth and development to replace diseased or damaged tissue. This approach may be used to treat:

Regenerative medicine refers to novel:

A cell that has the capacity to differentiate into a limited number of related cell types is a _____ stem cell.

Review Figure 20.19. Which floral organ develops from whorl 4 in Arabidopsis?

What floral organs would develop in Arabidopsis flower whorls 1, 2, 3, and 4 (in that order) in a mutant in which activity B was expressed in all four whorls?