1. Describe two cellular mechanisms that lead to changes in cell fate in an early cleavage embryo (2-3 sentences).
2.You found a strain of mutant fruit flies (Drosophila) living on the rotten bananas in your dorm room. You notice that many of the larvae have abnormal abdominal segments. You want to know if the “abdoless” mutation is a maternal effect gene. Describe an experiment you would do to determine this, and the results that would support and contradict the notion that the abdoless gene encodes a maternal determinant. (6-8 sentences or less)
3.You discover that zebrafish contain a gene that has a similar sequence to Drosophila abdoless. Describe TWO experiments you would do to test for a similar function. (no sentence limitation)
4.Describe the two specific experiments that strongly demonstrated the role and importance of egg intracellular calcium for proper fertilization. Please explain your rationale and the consequences of each experiment: (5-7 sentences or less)
5.Describe the definitive experiment that showed the totipotent nature of the nuclear genome and revealed the concept of genomic equivalence. Explain how your description supports the two concepts. (3-5 sentences).
6.Describe one of the two experiments discussed in the class that demonstrated the role of DNA ratios controlling maternal to zygotic transition. (one sentence)
7.As a scientist, you want to conduct a rescue experiment that requires allocating mRNA to the posterior end of the Drosophila egg. You have decided to generate a construct that will express your gene of interest. Please describe the elements necessary in your construct that will direct expression of your gene in the posterior end of the Drosophila egg. (2-3 sentences)
8.How would level and localization of hunchback protein and mRNA be affected in a Drosophila embryo with the genotype of Bicoid +/- derived from a Bicoid -/- mother? Why? (3-5 sentences).
9.Two fraternal twins were developing in the womb during the first trimester; however, by the end of the trimester, one twin absorbed the other. Please identify an appropriate characteristic for the surviving developing fetus; explain your rationale: (2-4 sentences)
10. What cellular phenomenon contributes to a directed and maintained path of differentiation? Please describe the phenomenon: