a) What is the role of the Hox genes in animal development and what types of phenotypes do you see in mutations of Hox genes? Provide an example of a mutant phenotype of a Hox gene in Drosophila. 3mrks The Hox genes are known to act in combination. Panel A in figure below shows the normal expression patterns of the bithorax complex, and segments that align with the expression patterns. Panel B shows the segmental phenotypes in mutants for both abdominal - A and Abdominal - B, panel C shows the phenotypes in mutants for Abdominal - B, and panel D shows the phenotypes in mutants for Ultrabithorax. b) Describe how the segmental phenotypes illustrate the combinatorial action of Hox genes (you can ignore A9 as it is patterned by the terminal patterning system). 4mrks A) Parasegments 11 12 13 14 B) D) 10 11 12 13 14 Segments A2 A3 A4 A5 Abdominal-B abdominal-A Ultrabithorax T1 12 13 A1 11 12 12 12 A2 A3 A4 A

Please answer question 10

Developmental abnormalities can result from: 1. Under expression of some genes 2. All of these choices are correct 3. Inappropriate interaction among gene products that were expressed in the wrong amounts and wrong time 4. Over expression of some genes 5. corrupted timing of the normal time genes are expressed

Below are data from Jimenez et al (2022) depicting cellular expression patterns of the tumor suppressor transcription factor p53 (a gene commonly mutated in cancers). They explored oscillating expression patterns found in a mutated human cell line. Panel D shows measurements of changes in p53 mRNA levels measured using two different approaches; figure E shows measurements of protein levels from the same samples. The numbers on either side indicate the observed fold change (FC) in relative abundance of these molecules (note that any difference in values obtained between the two methods are not relevant for this question). Answer part b as pictured in the question