A maternal effect gene called OSKAR is needed for the formation of posterior segments in Drosophila larvae. In a cross of an osk-/osk- male with an osk-/+ female, what can one expect among the F1 embryos?

The figure below depicts a snapshot of a circular DNA molecule early in the process of theta replication. A replication bubble has opened at the top of the molecule. Various landmarks are labeled around the DNA molecule with capital letters (A through M). Only the parent (template) DNA strands are shown in this diagram! It is your job to infer how and where the new, synthesized DNA strands are being made. You will use the capital letter landmarks (A through M) to indicate *where* the molecules listed below will be located on the parent DNA.   For each item below, fill in the blank with all the letter locations that apply. For example: if helicases are acting in more than one location on the DNA, you must indicate all locations for full points. Points will be deducted for listing incorrect locations, though, so don’t just write every letter in every blank. If you list multiple letters, please separate each of them with a comma. Location(s) where helicase is acting [helicase] Location(s) where topoisomerase is acting [topo] Location(s) where the replisome (DNA polymerase) is acting [replisome] Location(s) where you would find dnaA boxes [dnaA] Location(s) where you would find a termination site [termination] Location(s) where you would find Okazaki fragments [Okazaki] Location(s) where you would find leading strand(s) [leading]

In general, what is the difference between the default state of prokaryotic genes vs. eukaryotic genes?

The amino acid sequences shown in the following table were obtained from the central region of a particular polypeptide chain in the wild-type (WT) and several mutant bacterial strains (the whole protein is not shown, just an internal segment of it). Each mutant strain has a point mutation in the gene that produces the polypeptides listed in the table. Each mutant strain depicted contains only one mutation. A blank box indicates no amino acid codon exists in that position.   For each of the mutants, fill in the table below indicating what kind of mutation has occurred: missense, nonsense, synonymous, or frameshift, and in which codon (1-9) the mutation occurred. You do not need to distinguish between conservative and nonconservative missense mutations. Type of mutation Codon where mutation occurred Mutant 1 [answer1] [answer2] Mutant 2 [answer3] [answer4] Mutant 3 [answer5] [answer6] Mutant 4 [answer7] [answer8] Mutant 5 [answer9] [answer10]

From one F+ strain of E. coli, three distinct Hfr strains were derived (Hfr1, Hfr2, and Hfr3). All three Hfr strains were independently crossed to an F- strain. The first five markers transferred during these matings were:                          Hfr1: AFCED                            Hfr2: CEDBH                            Hfr3: AGHBD Which of the following must be the order of the genes on the bacterial chromosome?

For the mutant described in the last question, what is the fewest number of supplements you could provide to this mutant that would allow it to grow?

Despite high rates of spontaneous mutation at the sites described in the last question, E. coli continue to engage in cytosine methylation at these sites, indicating that methylation of this site is more important to cell survival than the potential damage of DNA mutation. Briefly, explain why you think E. coli do not abolish this methylation activity.

A linear DNA molecule has “n” number of EcoRI sites. How many DNA fragments will be produced after digestion with EcoRI? (note: “digestion” means being cut)

Gene H encodes an important protein involved in detecting sound. Individuals with an hh genotype have normal hearing. Individuals with an Hh genotype have an 85% lifetime risk of developing sudden, complete hearing loss. The H allele can be said to be….

A fragment of DNA has been submitted for Sanger sequencing and sequencing gel is shown below. What must have been the sequence of the original (template) strand of this fragment?