Flashcards in Miscellaneous Category Deck (33):
During embryogenesis, oocytes are halted in what phase?
Prophase of meiosis I before puberty.
In what stage does the secondary oocyte halt in meiosis?
In what meiotic state does a secondary oocyte remain until fertilization?
What do homeobox genes encode for?
DNA binding transcription factors that alter the genes expressed in morphogenesis.
What is morphogenesis?
The proper formation and placement of tissues, organs and structural elements of the body
What does 'degenerate' mean in terms of the genetic code?
More codons than amino acids
What is the monospot test?
Used to test for mononucleosis- A positive test involves agglutination of sheep erythrocytes.
What is detected by a southwestern blot?
DNA binding protein
What is used to detect DNA binding proteins in western blots?
Double stranded DNA probes.
What are c-Jun and c-fos?
DNA binding proteins that bind DNA via a leucine zipper motif.
What types of proteins are detected by Southwestern blots?
Transcription factors, nucleases, histones.
What is the 16S rRNA and where is it found?
Found in the 30S subunit of prokaryotes. It contains a sequence complementary to Shine Delgarno sequence on mRNA; their binding initiates protein translation.
How is the polyA tail transcribed?
Added as a posttranscriptional modification downstream of a consensus sequence; it is not transcribed from DNA
What is the poly A tail consensus sequence?
What are the stop codons and what factors recognize and release them to terminate protein synthesis?
Releasing factors 1 and 3; they are UAA, UAG, UGA
Name two properties of drugs with high intrinsic hepatic clearance?
High lipophillicity and high volume of distribution.
What is the primary role of the liver vs the kidney in excretion?
Kidney- primary site of elimination; Liver- biotransformation to prepare for elimination.
Describe the difference in location between enhancers/repressors and promoters in eukaryotic transcribed genes.
Promoters are located 25-70 bps upstream of their associated genes; enhancers/repressors can be located anywhere.
What types of viruses are capable of genetic shifts through reassortment?
Viruses with segmented genomes (orthomyxoviruses, rotaviruses, etc.)
What is the difference between genetic drift and genetic drift in terms of genome information alterations?
In genetic drifts, there is a single point mutation; in shifts, there is transfer of an entire segment of genome.
What is expression cloning?
A type of DNA cloning where the signals necessary for transcription and translation are included in the cloned DNA; it allows bacteria to produce large amounts of a protein of interest.
Name six types of proteins that can bind DNA and thus can be detected by DNA binding probes.
Transcription factors, steroids, thyroid proteins, vitamin D receptors, retinoic acid receptors, DNA transcription and replication proteins.
In Downs syndrome, maternal nondisjunction occurs most commonly in what phase?
What is phenotypic mixing?
Co-infection of a host cell by two viral strains, resulting in progeny virons that contain nucleotide capsid proteins from one strain and the genome of another strain. There is no change in genome so the next generation reverts to their original phenotypes.
What is viral interference?
Inhibition by one virus of the replication and/or release of a second virus that is infecting the same cell.
When is b-hCG detectable in maternal serum after ovulation?
Only after the blastocyst successfully implants. Implantation generally occurs on day 6 after ovulation thus b-hCG is usually detectable about 8 days after ovulation but it may take up to 11 days.
What types of polymerases are used to by DNA to begin synthesis of daughter strands?
DNA dependent RNA polymerases.
What enzyme removes RNA primers in bacterial DNA synthesis?
DNA polymerase I
What is special about bacterial DNA polymerase I?
It is the only bacterial DNA polymerase with 5'-3' exonuclease activity.
Which histone proteins are not part of the nucleosome and are used to facilitate and package nucleosomes into compact structures?
What is the function of H1 histones?
To bind the segment of DNA that lies between nucleosomes and facilitate the packaging of nucleosomes into more compact structures.
In patients treated for allergic rhinitis, what type of receptor block causes facial flushing and pupillary dilation?
Muscarinic receptor blocking