Concept explainers
To review:
Whether the following examples are description of genetics at the molecular, cellular, organism or population level.
A. The HbS allele encodes a polypeptide that functions slightly differently from the polypeptide encoded by the HbA allele.
B. If an individual has two copies of the Hbs allele, that person’s red blood cells take on a sickle shape.
C. Individuals who have two copies of the HbA allele do not have sickle cell disease, but they are not resistant to malaria. People who have one HbA allele and one HbS allele do not have sickle cell disease and are resistant to malaria. People who have two copies of the HbS allele have sickle cell disease and this disease may significantly shorten their lives.
D. Individuals with sickle cell disease have anemia because their red blood cells are destroyed by the body.
Introduction:
The blood disease called sickle cell anemia is a heritable disease. The affected individuals do not have enough oxygen-carrying hemoglobin in their blood, which causes the red blood cells (RBCs) to shrink and acquire a sickle shape. This happens due to the defective β–globin gene.
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Chapter 1 Solutions
Genetics: Analysis and Principles
- The HbβS(sickle-cell) allele of the human β-globingene changes the sixth amino acid in the β-globinchain from glutamic acid to valine. In HbβC, the sixthamino acid in β-globin is changed from glutamic acidto lysine. What would be the order of these two mutations within the map of the β-globin gene?arrow_forwardAlzheimer’s is a progressive neurological disorder resulting in dementia and memory loss that occurs in 10% of the US population older than 65. In the 1990s, several researchers showed evidence that the allele of a cholesterol precursor gene, APO E4, increased risk of developing the disorder compared to APO E2 or APO E3. This was especially pronounced if patients carried two alleles of APO E4. However, not all people with APO E4 develop the disorder and some without it will present with Alzheimer's nevertheless. This suggests other genes influence development of the disease. Current research has elucidated dozens of genes that interact with APO E4 pathways in hundreds of ways. As many as 27 of the interactions are epistatic, with some as dominant epistasis and some as recessive epistasis. In addition, some of the gene candidates for non-APO E4 Alzheimer’s have other relationships such as dominant, codominant or incomplete dominant. No reliable cure currently exists for Alzheimer’s…arrow_forwardAlzheimer’s is a progressive neurological disorder resulting in dementia and memory loss that occurs in 10% of the US population older than 65. In the 1990s, several researchers showed evidence that the allele of a cholesterol precursor gene, APO E4, increased risk of developing the disorder compared to APO E2 or APO E3. This was especially pronounced if patients carried two alleles of APO E4. However, not all people with APO E4 develop the disorder and some without it will present with Alzheimer's nevertheless. This suggests other genes influence development of the disease. Current research has elucidated dozens of genes that interact with APO E4 pathways in hundreds of ways. As many as 27 of the interactions are epistatic, with some as dominant epistasis and some as recessive epistasis. In addition, some of the gene candidates for non-APO E4 Alzheimer’s have other relationships such as dominant, codominant or incomplete dominant. No reliable cure currently exists for Alzheimer’s…arrow_forward
- Alzheimer’s is a progressive neurological disorder resulting in dementia and memory loss that occurs in 10% of the US population older than 65. In the 1990s, several researchers showed evidence that the allele of a cholesterol precursor gene, APO E4, increased risk of developing the disorder compared to APO E2 or APO E3. This was especially pronounced if patients carried two alleles of APO E4. However, not all people with APO E4 develop the disorder and some without it will present with Alzheimer's nevertheless. This suggests other genes influence development of the disease. Current research has elucidated dozens of genes that interact with APO E4 pathways in hundreds of ways. As many as 27 of the interactions are epistatic, with some as dominant epistasis and some as recessive epistasis. In addition, some of the gene candidates for non-APO E4 Alzheimer’s have other relationships such as dominant, codominant or incomplete dominant. No reliable cure currently exists for Alzheimer’s…arrow_forwardThe gene known to be mutated in cases of Agammaglobulinemia 2 (which is inherited in an autosomal recessive pattern) is the immunoglobulin lambda like polypeptide 1 (IGLL1 ENSG00000128322). What is known about the gene is recorded here: http://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000128322;r=22:23573125-23580302 Please navigate to the link above to answer the following question: According to the web site above, how many phenotypes is IGLL1 associated with? ANSWER: IGLL1 is associated with Blank ... phenotypes.arrow_forwardThe gene known to be mutated in cases of Agammaglobulinemia 2 (which is inherited in an autosomal recessive pattern) is the immunoglobulin lambda like polypeptide 1 (IGLL1 ENSG00000128322). What is known about the gene is recorded here: http://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000128322;r=22:23573125-23580302 Please navigate to the link above and click, 'show transcript table', to answer the following question: What is the size in base pairs of the IGLL1 transcript named IGLL-202?arrow_forward
- The gene known to be mutated in cases of Agammaglobulinemia 2 (which is inherited in an autosomal recessive pattern) is the immunoglobulin lambda like polypeptide 1 (IGLL1 ENSG00000128322). What is known about the gene is recorded here: http://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000128322;r=22:23573125-23580302 Please navigate to the link above and click, 'show transcript table', to answer the following question: What is the size in amino acid residues of the IGLL1 transcript named IGLL1-203? NOTE: Please give your answer as a number, not a word, and do not type the units.arrow_forwardThe gene known to be mutated in cases of Agammaglobulinemia 2 (which is inherited in an autosomal recessive pattern) is the immunoglobulin lambda like polypeptide 1 (IGLL1 ENSG00000128322). What is known about the gene is recorded here: http://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000128322;r=22:23573125-23580302 Please navigate to the link above to answer the following question: Using the left-hand menu to view the sequence for IGLL1, what are the last 12 nucleic acid bases of exon 1?arrow_forwardA haplotype is a set of DNA variations, or polymorphisms, that tend to be inherited together. A haplotype can refer to a combination of alleles or to a set of single nucleotide polymorphisms (SNPs) found on the same chromosome. Each SNP represents a difference in a single nucleotide. For example, an SNP may replace the cytosine (C) with thymine (T) in a certain stretch of DNA. SNPs occur normally throughout a person’s DNA. They occur almost once in every 1,000 nucleotides on average, which means there are roughly 4 to 5 million SNPs in a person's genome. These variations may be unique or occur in many individuals; Most commonly, these variations are found in the DNA between genes. They can act as biological markers, helping scientists locate genes that are associated with disease. When SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene’s function. Nucleotide Position…arrow_forward
- The Hemoglobin gene has two very common alleles: HbS and HbA. Bob’s professor asks him to draw the chromosomes for an individual that is HbSHbA and label the alleles. Bob draws this (below). Explain why Bob is wrong and then draw it correctly. FOXP2 is a gene in humans; humans that have mutated copies of FOXP2 often have trouble speaking. It is on Chromosome 7, which is about 160 million base pairs long. FOXP2 is at position 115 million base pairs. Which of the drawings below appropriately diagrams the location of FOXP2? Why?arrow_forwardFamilial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior history of the disease. Consider the following pedigree (the darkly colored symbols represent affected individuals): a. Circle the individual(s) in which the mutation most likely occurred. b. Is the person who is the source of the mutation affected by retinoblastoma? Justify your answer. c. Assuming that the mutant allele is fully penetrant, what is the chance that an affected individual will have an affected child?arrow_forwardIn mice, the A allele causes agouti fur, the AY allele causes yellow fur and is dominant to the A allele. The homozygous AY AY genotype is lethal. Why is the AYAY homozygous condition lethal? The AY allele highly transcribes the merc gene which is lethal in a homozygous AYAY individual. None of the other answers are correct. The AY allele lacks an upstream merc gene which is required for normal embryonic development. The AY allele contains a null mutation in the A gene, which is required for normal embryonic development. The yellow pigment produced by A allele is required for survival.arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning