Molecular Genetics — Flashcards

Flashcard 371: 5α-reductase deficiency = _____

Answer: 46XY

Extra:  https://onlinemeded.org/spa/obgyn?ref=anki 

Flashcard 372: What serum marker is characteristically elevated in choriocarcinoma? _____

Answer: β-hCG

Extra: β-hCG is characteristically elevated in choriocarcinoma, hydatidiform moles, and gestational trophoblastic disease. It is also used to monitor treatment response and screen for recurrence.

Flashcard 373: Chronic myeloproliferative disorders (except CML) are associated with _____ mutations - the mutation is in a gene encoding a(n) tyrosine kinase, which causes tyrosine hyperphosphorylation and hypersensitivity of progenitor cells to cytokines, prolonging cellular growth

Answer: V617F JAK2

Extra:   https://onlinemeded.org/spa/hematology-oncology/leukemia/acquire?ref=anki 

Flashcard 374: HbH and Hgb Barts = _____ thalassemia ↑ HbA2 and ↑ HbF = _____ thalassemia

Answer: alpha

Extra:  https://onlinemeded.org?ref=anki 

Flashcard 375: 34 y/o woman comes for breast examination. -Screening test was performed using Polymerase chain reaction (PCR) to amplify the target of exon. -Gel electrophoresis to assess the size of the exon compared to the wild type allele.What features must be known in order to perform the amplification part of this analysis?

Answer: The nucleotide sequence of the DNA regions flanking the target exon (required for primer synthesis).

Flashcard 376: Evaluate the following statements regarding **both** eukaryotic and prokaryotic DNA replication: - Continuous synthesis of the lagging strand - Energy-independent DNA unwinding - Multiple origins of replication - No proofreading of daughter strands - No requirement for RNA primers

Answer: All statements are **FALSE**. - **Lagging strand**: Discontinuous in both (Okazaki fragments). - **Unwinding**: Both require ATP-dependent helicase. - **Origins**: Prokaryotes typically have one; eukaryotes have multiple. - **Proofreading**: Both possess 3'→5' exonuclease activity. - **Primers**: Both require RNA primers synthesized by primase.

Flashcard 377: In a research study, small circular DNA molecules that resemble a bacterial chromosome are isolated from exocrine pancreatic cells. Further analysis shows that these molecules code for proteins, transfer RNA, and ribosomal RNA. From which of the following cellular structures did these DNA molecules most likely originate?

Answer: Mitochondria Mitochondria contain circular DNA chromosomes that resemble bacterial (prokaryotic) chromosomes. They are inherited maternally and encode their own proteins, transfer RNA (tRNA), and ribosomal RNA (rRNA).

Flashcard 378: A genetic researcher is comparing the DNA replication process of prokaryotic and eukaryotic cells. - E. coli and human cells are cultured in separate media containing tagged nucleotides and their rates of DNA replication are determined. - Eukaryotic DNA is much larger and more complex, but replication still occurs in a timely manner. - Which feature of eukaryotic replication best explains this observation?

Answer: Multiple origins of replication

Extra: Eukaryotic chromosomes are large and linear with multiple origins of replication, allowing simultaneous replication at many points. In contrast, prokaryotes (like E. coli) typically have a single circular chromosome with a single origin of replication (oriC). Despite prokaryotic DNA polymerases being faster, the multiple origins in eukaryotes allow for faster overall genome replication.

Flashcard 379: In an experiment, a protein mixture obtained from a cell culture is separated by gel electrophoresis and subsequently transferred to a filter membrane. -Labeled: Double-stranded DNA probes are used to detect a specific protein of interest in the sample. -What protein is most likely to be detected by this method? a.) Ras b.) C-Jun c.) B1- adrenoreceptor d.) S-100 e.) Adenylate cyclase

Answer: C-jun Other possible answers: c-Fos, or c-Jun & c-Fos because Double stranded DNA probes were use, which means they are using Southwestern blotting technique, (DNA - binding protein).

Flashcard 380: Describe these 2 genetics term? -Transition -Transversion

Answer: Transition: you replaced a purine by a purine, a pyrimidine by a pyrimidine. -Transversion: you replaced a purine by a pyrimidine. A pyrimidine by a purine.