\"You are a graduate student in Gregor Mendel’s lab researching the inheritance
ID: 260069 • Letter: #
Question
"You are a graduate student in Gregor Mendel’s lab researching the inheritance pattern of pea pod shape. You have obtained two sets of true-breeding plants – one that has full pods and one that has constricted pods, with the full pod phenotype being dominant. Write out your experimental plan for an F1 cross indicating the following: parental genotypes and phenotypes, progeny genotypes and phenotypes (including ratios for both)"
DNA sequencing reveals that the gene in the question above encodes the protein tubulin, the subunit of microtubules which provide structural support to cells. For the plants with constricted pods: Briefly describe how one type of point mutation could lead to the absence of tubulin and Briefly describe one way in which regulation of gene expression, excluding alternative splicing, could lead to the absence of tubulin
Explanation / Answer
Let full pods be dominant and constricted be recessive in nature.
Genotype for full pea pods.=PP
Genotype for constricted pods.=yy
Breeding YY×yy
F1- Yy Yy both have full pea pods.
F2-Yy×Yy
YY, Yy ,Yy, yy
Where only yy is constricted remaining full pea pods.
Ratio of full:constricted =3:1
A point mutation in tubulin could lead to the disruption in microtubule dynamics, polymerization --depolymerization at one of the end may get affected . The tubulin protein may attain a structure that is not thermodynamically stable , has higher entropy and gets degraded due to the point mutation. Thus tubulin may become absent.
Correct Spatiotemporal regulation of tubulin is important for functionality of tubulin. Incorrrect RNA splicing due to defect in recognition of many splicing proteins to RNA may effect the gene expression per se. Also defect in recognition by spliceosome due to mutation may also affect tubulin gene expression.
For eg: if mutation is in the splicing region say exon 10 then pathologies may be introduced into the sysyem.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.