l5 SAQ Genetics Quiz

A haplotype is a set of polymorphisms that are grouped tightly together on a single chromosome and tend to be inherited together through many generations.

Microsatellites can be used as genetic markers to track haplotypes.

Linkage analysis is a method used to associate haplotypes with traits or map genes to characters.

<p>A gene is a biological determinant of a Mendelian character or trait.</p> Signup and view all the answers

<p>A haplogroup is a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation.</p> Signup and view all the answers

<p>Crossing over in meiosis I results in the exchange of genetic material between homologous chromosomes.</p> Signup and view all the answers

<p>Haplotypes are not separated by crossing over and tend to be inherited together through many generations.</p> Signup and view all the answers

<p>A haploid genotype refers to a set of polymorphisms that are grouped tightly together on a single chromosome and tend to be inherited together through many generations.</p> Signup and view all the answers

<p>SNPs, or single nucleotide polymorphisms, are genetic markers that can be used to define haplotypes.</p> Signup and view all the answers

<p>DNA/genetic signature refers to a combination of alleles or a set of single nucleotide polymorphisms that can be used to identify a specific haplotype.</p> Signup and view all the answers

<p>Genetic recombination is the process by which new combinations of genetic material are produced through the exchange of genetic material between different organisms. Gene mapping is the process of determining the relative positions of genes on a chromosome and the distance between them.</p> Signup and view all the answers

<p>Thomas Hunt Morgan proved the chromosome theory of heredity by studying the inheritance of traits in fruit flies. He observed sex-linked inheritance of recessive white eye color in mutant males and noticed that some genes were &quot;linked&quot; and inherited together. He theorized that crossing-over during genetic recombination was the reason for the occasional separation of linked genes.</p> Signup and view all the answers

<p>A chromosomal linkage map is a map that shows the relative positions of genes on a chromosome based on their likelihood of being inherited together. Genes that are closely linked, meaning they are located close to each other on the chromosome, are more likely to be inherited together.</p> Signup and view all the answers

<p>If related individuals with the same trait have a common haplotype, it can be assumed that the gene responsible for the shared trait is located in that area. By comparing the haplotypes of related individuals, scientists can narrow down the region of the genome to focus on for further investigation.</p> Signup and view all the answers

<p>Tandem repeat non-coding DNA sequences are series of nucleotides that are directly repeated within a DNA sequence. They are called tandem repeats because the repeats are adjacent to each other. These sequences are non-coding, meaning they do not contain instructions for making proteins.</p> Signup and view all the answers

<p>The three types of tandem repeats are satellite DNA, minisatellite DNA, and microsatellite DNA.</p> Signup and view all the answers

<p>Satellite DNA consists of very large arrays of non-coding tandemly repeating DNA. The length of the repeat unit is usually greater than 100 base pairs, and the sequences vary between individuals. An example of satellite DNA is alphoid DNA, which is found in centromeric heterochromatin.</p> Signup and view all the answers

<p>Minisatellite DNA is of medium size, with an array length ranging from 100 base pairs to 20 kilobases. The length of the repeat unit is typically 10-100 base pairs. Minisatellite DNA has a high mutation rate and high diversity in the population. Variable number tandem repeats (VNTRs) are a type of minisatellite DNA with 5-50 repeats of a 20 base pair sequence.</p> Signup and view all the answers

<p>Microsatellite DNA, also known as simple sequence repeats (SSRs) or short tandem repeats (STRs), consists of arrays usually less than 100 base pairs in length. The repeat unit is typically 2-4 base pairs. Microsatellite DNA is commonly used in genetic linkage analysis to locate genes or mutations associated with specific traits or diseases.</p> Signup and view all the answers

<p>Genetic markers, such as tandem repeat sequences, can be used to identify specific haplotypes. By analyzing the presence or absence of certain markers in an individual's genome, scientists can determine which haplotypes they possess. This information is valuable in studies of population genetics, disease association, and forensic analysis.</p> Signup and view all the answers

<p>Consanguinity refers to being descended from the same ancestor as another person. Consanguineous mating, such as first cousin marriages, can increase the risk for hereditary disorders because it increases the likelihood of inheriting two copies of a harmful recessive allele.</p> Signup and view all the answers

<p>Molecular 'bar coding' of haplotypes using microsatellites can be used to track hereditary disease in consanguineous lineages by analyzing the variations in microsatellite DNA sequences. These variations can serve as genetic markers, allowing researchers to trace the inheritance of specific alleles or mutations linked to the disease.</p> Signup and view all the answers

<p>The coefficient of relationship measures the genetic relatedness between two individuals, while the coefficient of inbreeding quantifies the probability of inheriting two copies of an allele from a common ancestor. Both coefficients are used to calculate the inheritance risk for autosomal recessive disorders in children of consanguineous couples.</p> Signup and view all the answers

<p>The Hardy-Weinberg principle states that in a large, randomly mating population, the allele and genotype frequencies will remain constant from generation to generation in the absence of evolutionary forces. The equation used to calculate allele and genotype frequencies is p^2 + 2pq + q^2 = 1, where p and q represent the frequencies of the two alleles in the population.</p> Signup and view all the answers

<p>In a population in Hardy-Weinberg equilibrium, the genotype frequencies can be used to calculate the probability of inheriting a specific genotype. For example, the probability of inheriting two copies of the recessive allele (q^2) represents the inheritance risk for autosomal recessive disorders.</p> Signup and view all the answers

<p>Consanguineous marriage is the matrimony (breeding) between two family members who are second cousins or closer.</p> Signup and view all the answers

<p>Consanguineous marriage is associated with an increased risk of autosomal recessive disorders.</p> Signup and view all the answers

<p>5% of children have consanguineous parents.</p> Signup and view all the answers

<p>The probability of having a child without a constitutional congenital defect is reduced from 98% to 96% in consanguineous marriages.</p> Signup and view all the answers

<p>The advantages of consanguineous marriage include preservation of identity, property, culture and tradition, partnerships with people from similar backgrounds, stronger family ties, financial advantages, and bride protection.</p> Signup and view all the answers

<p>The probability that Nasreen's sibling will be homozygous for the deafness-associated haplotype is 25%.</p> Signup and view all the answers

<p>The coefficient of relationship (COR) between full siblings is 50%.</p> Signup and view all the answers

<p>The coefficient of inbreeding (COI) for a person whose parents are half-siblings is 12.5%.</p> Signup and view all the answers

<p>Allele frequency can be calculated by dividing the number of times the allele of interest is observed in a population by the total number of copies of all the alleles at that locus in the population.</p> Signup and view all the answers

<p>The allele frequency is $\rac{40}{200} = 0.2$ or 20%.</p> Signup and view all the answers

<p>The Hardy-Weinberg principle, also known as the Hardy-Weinberg equilibrium, model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.</p> Signup and view all the answers

<p>The Hardy-Weinberg equation is (p + q)^2 = 1 or p^2 + 2pq + q^2 = 1, where p = frequency of allele 'A' and q = frequency of allele 'a'.</p> Signup and view all the answers

<p>A population remains in Hardy-Weinberg equilibrium under certain assumptions, including the absence of selection and random mating (a panmictic population).</p> Signup and view all the answers

<p>In clinical genetics, the frequency of heterozygosity (carrier frequency) is determined using the equation p^2 + 2pq + q^2 = 1 or f(AA) + f(Aa) + f(aa) = 1, where p + q = 1.</p> Signup and view all the answers

<p>If the frequency of allele R1 is 40% (p = 0.4), the proportion of the population with allele R1 can be determined using the equation (p^2 + 2pq + q^2) = 1. Therefore, (0.4)(0.4) + 2(0.4)(0.6) + (0.6)(0.6) = 0.16 + 0.48 + 0.36 = 1. Thus, 16% of the population are (R1,R1) homozygous and 48% are (R1,Rx) heterozygous. Therefore, 64% of the population has allele R1.</p> Signup and view all the answers