Videos
A researcher was asked if his work on human telomere replication was related to any genetic disorders. He replied that one might think that any such mutations would be lethal during early development, but in fact a rare human genetic disorder affecting telomeres is known. This disorder, dyskeratosiscongenita (DKC), is associated with mutations in the protein subunits of telomerase, the enzyme responsible for replicating the ends of eukaryotic chromosomes. Initial symptoms appear in tissues derived from rapidly dividing cells, including the skin, nails, and bone marrow, and first affect children between the ages of 5 and 15 years.
How could such individuals survive?
To review:
The survivability of people with Dyskeratosis congenita (DKC).
Introduction:
Dyskeratosis congenital (DKC) is a rare genetic X chromosome-linked disease. Initial symptoms of this disease show up between the age of 5 to 15 years. People with DKC has the mutation on telomerase gene thus has non-functional telomerase. This disease affects the tissues with rapidly growing cells like skin, nails, and bone marrow.
Explanation of Solution
The tail region of the eukaryotic chromosome is known as the telomere. This region does not contain any functional genes but only guanine and a cytosine-rich tandem repeat of nucleotides. DNA (deoxyribonucleic acid) polymerase responsible for DNA replication cannot replicate the telomere region efficiently. Thus telomerase play a crucial role in replication of telomere. Here in case of persons withDyskeratosis congenita (DKC), after every successful cell division, a part of the telomere region gets lost in the newly divided cell. This problem is known as end replication problem.
The eukaryotic cells use telomerase to replicate telomere, which can successfully replicate the telomere region without losing any of its regions. The whole telomere region of the people with non-functional telomerase gets lost after a few early cell division. However, as this telomere region does not has any functional genes that could affect the cell functionality, early cell divisions can occur smoothly.
The patients can survive early development. Once the whole telomere region gets lost and functional genes present near the telomere region starts getting lost due to further cell division, only then, the patients show symptoms of DKC. That occursnormally between 5- 15 years of age.
Dyskeratosis congenita (DKC) appears among people who have mutated loss-in-function telomerase. Therefore, it can be concluded that the people with non-functional telomerase can survive early development. After that, they will start showing symptoms ofDKC, which includes nail dystrophy, abnormal skin pigmentation, and bone marrow failure.
Want to see more full solutions like this?
Chapter 10 Solutions
Essentials of Genetics (9th Edition) - Standalone book
- the direct output from molecular replacement is a coordinate file showing the orientation of the unknown target protein in the unit cell. true or false?arrow_forwardDid your intake of vitamin C meet or come very close to the recommended amount? yes noarrow_forwardWhich of the following statements about hydration is true? Absence of thirst is a reliable indication that an individual is adequately hydrated. All of these statements are true. Although a popular way to monitor hydration status, weighing yourself before and after intensive physical activity is not a reliable method to monitor hydration. Urine that is the color of apple juice indicates dehydration. I don't know yetarrow_forward
- Three of the many recessive mutations in Drosophila melanogaster that affect body color, wing shape, or bristle morphology are black (b) body versus grey in wild type, dumpy (dp), obliquely truncated wings versus long wings in the male, and hooked (hk) bristles versus not hooked in the wild type. From a cross of a dumpy female with a black and hooked male, all of the F1 were wild type for all three of the characters. The testcross of an F1 female with a dumpy, black, hooked male gave the following results: Trait Number of individuals Wild type 169 Black 19 Black, hooked 301 Dumpy, hooked 21 Hooked, dumpy, black 172 Dumpy, black 6 Dumpy 305 Hooked 8 Determine the order of the genes and the mapping distance between genes. Determine the coefficient of confidence for the portion of the chromosome involved in the cross. How much interference takes place in the cross?arrow_forwardWhat happens to a microbes membrane at colder temperature?arrow_forwardGenes at loci f, m, and w are linked, but their order is unknown. The F1 heterozygotes from a cross of FFMMWW x ffmmww are test crossed. The most frequent phenotypes in the test cross progeny will be FMW and fmw regardless of what the gene order turns out to be. What classes of testcross progeny (phenotypes) would be least frequent if locus m is in the middle? What classes would be least frequent if locus f is in the middle? What classes would be least frequent if locus w is in the middle?arrow_forward
- 1. In the following illustration of a phospholipid... (Chemistry Primer and Video 2-2, 2-3 and 2-5) a. Label which chains contain saturated fatty acids and non-saturated fatty acids. b. Label all the areas where the following bonds could form with other molecules which are not shown. i. Hydrogen bonds ii. Ionic Bonds iii. Hydrophobic Interactions 12-6 HICIH HICIH HICHH HICHH HICIH OHHHHHHHHHHHHHHHHH C-C-C-C-C-c-c-c-c-c-c-c-c-c-c-c-C-C-H HH H H H H H H H H H H H H H H H H H HO H-C-O H-C-O- O O-P-O-C-H H T HICIH HICIH HICIH HICIH HHHHHHH HICIH HICIH HICIH 0=C HIC -C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C-H HHHHHHHHH IIIIIIII HHHHHHHH (e-osbiv)arrow_forwardAnswer this as a dental assistant studentarrow_forwardbuatkan judul skripsi tentang parasitologi yang sedang trendinharrow_forward
- Dental assistantarrow_forwardO Macmillan Learning Glu-His-Trp-Ser-Gly-Leu-Arg-Pro-Gly The pKa values for the peptide's side chains, terminal amino groups, and carboxyl groups are provided in the table. Amino acid Amino pKa Carboxyl pKa Side-chain pKa glutamate 9.60 2.34 histidine 9.17 1.82 4.25 6.00 tryptophan 9.39 2.38 serine 9.15 2.21 glycine 9.60 2.34 leucine 9.60 2.36 arginine 9.04 2.17 12.48 proline 10.96 1.99 Calculate the net charge of the molecule at pH 3. net charge at pH 3: Calculate the net charge of the molecule at pH 8. net charge at pH 8: Calculate the net charge of the molecule at pH 11. net charge at pH 11: Estimate the isoelectric point (pl) for this peptide. pl:arrow_forwardBiology Questionarrow_forward
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Essentials of Pharmacology for Health ProfessionsNursingISBN:9781305441620Author:WOODROWPublisher:Cengage
Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning