Genetic Disorders and DNA Structure Quiz

Genetic disorders are illnesses caused by abnormalities in the genome, arising from heritable mutations or new defects in DNA.

DNA is packaged into chromosomes, which are structures composed of DNA and associated proteins.

Genes form only about 1.5% of the human genome.

<p>Exons contain the coding information for proteins, while introns are non-coding sequences that are typically removed during mRNA processing.</p> Signup and view all the answers

<p>Genotype refers to the alleles present in an individual, while phenotype is the visible or clinically apparent expression of those alleles.</p> Signup and view all the answers

<p>Genetic heterogeneity refers to a common phenotype that can arise from different genotypes.</p> Signup and view all the answers

<p>A mutation is an alteration in the DNA sequence that deviates from the normal genetic code.</p> Signup and view all the answers

<p>Certain cancers can arise from inherited genetic conditions, new mutations, or non-genetic causes.</p> Signup and view all the answers

<p>A proto-oncogene is a normal gene that regulates cell growth and can become an oncogene due to mutations.</p> Signup and view all the answers

<p>Examples of proto-oncogenes include RAS and MYC.</p> Signup and view all the answers

<p>The two mechanisms are quantitative, involving an increase in protein products, and qualitative, involving changes in nucleotide sequences.</p> Signup and view all the answers

<p>A missense mutation results in a change of a single amino acid, while a nonsense mutation changes a codon to a stop codon.</p> Signup and view all the answers

<p>They appear as recessive traits because one normal copy of the gene can produce enough enzyme for normal function.</p> Signup and view all the answers

<p>An insertion mutation involves the gain of a single base pair.</p> Signup and view all the answers

<p>Human chromosomes are composed of DNA packaged with proteins and consist of 23 pairs, including 22 autosomes and one pair of sex chromosomes.</p> Signup and view all the answers

<p>Haploid refers to a cell that contains a single set of chromosomes, which is the case for human gametes.</p> Signup and view all the answers

<p>A missense mutation.</p> Signup and view all the answers

<p>A 'dominant negative' effect occurs when a mutated gene product interferes with the normal protein's function, disrupting complex protein structures.</p> Signup and view all the answers

<p>Family history, dietary influence, smoking, and obesity are key factors.</p> Signup and view all the answers

<p>They deduced the double helical structure of DNA.</p> Signup and view all the answers

<p>A mutation in the fibrillin gene.</p> Signup and view all the answers

<p>Affected individuals are typically tall with long fingers, loose joints, and may have ocular issues and a risk of aortic rupture.</p> Signup and view all the answers

<p>Restriction enzymes are used to cut DNA into reproducible pieces for gene cloning.</p> Signup and view all the answers

<p>They demonstrated that pre-mRNA is processed by excising introns and splicing together exons.</p> Signup and view all the answers

<p>X-inactivation can lead to some genes being non-functional while others remain active, often causing females to be carriers without showing symptoms.</p> Signup and view all the answers

<p>Factor VIII is a blood clotting protein, and its activity levels determine the severity of hemophilia A, varying from mild to severe.</p> Signup and view all the answers

<p>The Human Genome Initiative was announced.</p> Signup and view all the answers

<p>The first draft was published in 2001.</p> Signup and view all the answers

<p>Reduced penetrance means the gene is present but does not always manifest as a phenotype in the parent, potentially skipping generations.</p> Signup and view all the answers

<p>Multifactorial inheritance refers to traits that result from the interaction of multiple genes and environmental factors.</p> Signup and view all the answers

<p>The Human Genome Project was completed.</p> Signup and view all the answers

<p>Leroy Hood developed the automated sequencing mechanism.</p> Signup and view all the answers

<p>The main types of chromosomal disorders are numerical and structural disorders. Numerical disorders involve changes in the number of chromosomes, while structural disorders involve changes in the structure of chromosomes.</p> Signup and view all the answers

<p>Down syndrome, or trisomy 21, is caused by an extra copy of chromosome 21, resulting in a total of 47 chromosomes. It is characterized by distinctive facial features, short stature, and varying degrees of intellectual disability.</p> Signup and view all the answers

<p>The standard recurrence risk for autosomal recessive conditions is 25%. This is because both parents must be carriers of the mutated gene for there to be a chance of having an affected child.</p> Signup and view all the answers

<p>Sickle cell anemia is an autosomal recessive condition caused by a point mutation in the beta globin gene. This mutation leads to the production of an abnormal beta globin chain, causing red blood cells to deform into a sickle shape under low oxygen conditions.</p> Signup and view all the answers

<p>Common chromosomal abnormalities include trisomy 13 (Patau syndrome), trisomy 18 (Edwards syndrome), and complex abnormalities like Klinefelter syndrome (47 XXY). Each of these conditions is characterized by specific physical and health-related traits.</p> Signup and view all the answers

<p>Prader-Willi syndrome is characterized by hyperphagia (compulsive overeating), mild to moderate mental retardation, short stature, small external genitalia, and hypotonia. It results from a deletion at chromosome 15.</p> Signup and view all the answers

<p>Mendelian inheritance patterns in chromosomal disorders manifest as autosomal recessive, autosomal dominant, or X-linked conditions. Each pattern affects the likelihood of offspring inheriting certain traits or disorders based on parental genotype.</p> Signup and view all the answers

<p>Aneuploidy refers to the presence of an abnormal number of chromosomes, such as monosomy or trisomy. An example is Down syndrome, which is the result of trisomy 21, where there is an extra chromosome.</p> Signup and view all the answers

<p>Nucleic acid probes are used to detect genetic information of a pathogen in a sample, thereby identifying diseases like TB.</p> Signup and view all the answers

<p>These assays help detect surface markers that may be absent or present in small amounts, indicating the presence of leukemia.</p> Signup and view all the answers

<p>The Philadelphia chromosome indicates the genetic abnormality t(9;22), which can be detected using specific probes for the c-abl-bcr gene rearrangement.</p> Signup and view all the answers

<p>Techniques include IHC, FISH, CISH, PCR, genetic mapping, and DNA typing.</p> Signup and view all the answers

<p>Therapeutic cloning involves extracting stem cells from embryos to treat various ailments.</p> Signup and view all the answers

<p>Gene splicing involves cutting DNA from one organism and inserting a gene, which is useful for recombinant technology to produce insulin and vaccines.</p> Signup and view all the answers

<p>DNA analysis, such as paternity testing, compares genetic markers between individuals to determine biological relationships.</p> Signup and view all the answers

<p>Identifying decomposed remains is challenging due to the degradation of DNA and tissue artifacts that may impede accurate matches.</p> Signup and view all the answers