#Question id: 2265
#Unit 2. Cellular Organization
Passage through pores in the nuclear envelope is restricted primarily to
#Question id: 4767
#Unit 8. Inheritance Biology
Neurofibromatosis is a condition in humans which is generally inherited in a dominant fashion. Assuming this disorder is 90% penetrant, what is the chance that a single child born to a father with neurofibromatosis and a mother known not to carry the mutation will have the disorder?
#Question id: 26844
#Unit 10. Ecological Principles
#Question id: 4780
#Unit 8. Inheritance Biology
In chickens, comb shape is determined by alleles at two loci (R, r and P, p). A walnut comb is produced when at least one dominant allele R is present at one locus and at least one dominant allele P is present at a second locus (genotype R_ P_). A rose comb is produced when at least one dominant allele is present at the first locus and two recessive alleles are present at the second locus (genotype R_pp). A pea comb is produced when two recessive alleles are present at the first locus and at least one dominant allele is present at the second (genotype rrP_). If two recessive alleles are present at the first and at the second locus (rrpp), a single comb is produced. Which of the following cross would produce ½ walnut and ½ pea comb ?
#Question id: 4267
#Unit 3. Fundamental Processes
The 3D structure of the complete Escherichia coli ribosome with bound mRNA and tRNAs revealed that the very amino terminus of one protein (L27) does reach into the active site. This finding suggested a role for this protein in catalysis. To test this possibility, the nine amino acids at the L27 amino terminus that were in close proximity to the active site were eliminated by mutation. The following possible outcomes were found to be correct as
A. The resulting cells produced ribosomes with reduced but detectable peptidyl transferase activity
B. Region of the L27 protein contributes to peptidyl transferase activity
C. The mutant ribosomes, didn’t synthesised wildtype levels of cells
D. Vast majority of this increase in peptide bond formation is retained, even without the presence of L27 in the active site
E. The most likely role for L27 is to correctly position one or more of the RNA components of the active site