Becker's World of the Cell (9th Edition)
9th Edition
ISBN: 9780321934925
Author: Jeff Hardin, Gregory Paul Bertoni
Publisher: PEARSON
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Chapter 23, Problem 23.5PS
The Eyes Have It. For this question, please consult Figure 23-21. Recall that each ommatidium in the compound eye contains a photoreceptor cell, R7, that must receive a signal from a neighboring cell, R8, to differentiate. This pathway depends on the Ras signaling pathway. Also, recall that mutants provide insight into this pathway. For each of the following situations, indicate whether the R7 cell would be expected to differentiate. In each case, clearly state your reasoning, based on your understanding of the molecular pathway involved.
- (a) R7 cells are mutated so that their Sevenless receptors lack the SH2-binding domain.
- (b) R7 cells are mutated so that they lack functional Sos but contain a constitutively active, dominant mutation in Ras.
- (c) R7 cells are mutated so that they have no functional MAP kinase.
- (d) R8 cells are mutated so that they produce too much of the Bride of sevenless ligand, and R7 cells lack Sevenless.
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Chapter 23 Solutions
Becker's World of the Cell (9th Edition)
Ch. 23 - One effect of the hormone insulin is to cause...Ch. 23 - You are working on a new species of sea urchin...Ch. 23 - The Ca2+ concentration in unstimulated cells is...Ch. 23 - Prob. 23.3CCCh. 23 - Prob. 23.4CCCh. 23 - Prob. 23.5CCCh. 23 - Chemical Signals and Second Messengers. Fill in...Ch. 23 - QUANTITATIVE Pure agony. Agonists are drugs that...Ch. 23 - Heterotrimeric and Monomeric G Proteins. G...Ch. 23 - Calcium Chelators and Ionophores. In addition to...
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