front 1 What are the 2 forms of dominance? | back 1 Incomplete and codominance |
front 2 What is incomplete dominance? | back 2 occurs when there is not a distinct dominant allele shown in the heterozygote. ex: a mix of a red and white flower making it pink |
front 3 What is codominance? | back 3 occurs when BOTH the dominant and recessive alleles are detectable in the heterozygous organism. ex: a brown and white cow makes a brown cow with white spots |
front 4 What are lethal alleles? | back 4 A gene is so mutated, that if an organism has two mutated copies, it will not survive to term |
front 5 What is a recessive lethal allele? | back 5 lethal alleles are naturally selected out of the population, as there
is no |
front 6 What are dominant lethal alleles? | back 6 lethal alleles still exist at low levels. This is because heterozygotes still carry the lethal alleles |
front 7 What can lethal alleles cause? | back 7 They can kill an offspring before it reaches term, or they can have a delayed age of onset |
front 8 What is happlosufficency? | back 8 means that with only one Wild type allele, you produce the
normal |
front 9 What is happloinsufficency? | back 9 means that only one Wild type allele can NOT produce the
normal |
front 10 What is a null (amorphic) mutation? | back 10 It is the COMPLETE loss of gene function as compared to wild type. ex: a pigment that was brown know no longer produces color. |
front 11 What is a leaky (hypomorphic) mutation? | back 11 A partial loss of gene function |
front 12 What is a dominant negative mutation? | back 12 When one mutation inactivates several parts of a protein complex |
front 13 What are the gain of function mutations? | back 13 hypermorphic and neomorphic mutations |
front 14 What is a hypermorphic mutation? | back 14 It occurs when a gene becomes more active than normal and it continues normal gene activity, but at a higher rate |
front 15 What is a neomorphic mutation? | back 15 It occurs when a gene takes on a NOVEL, or completely new function. |
front 16 What are sex limited traits? | back 16 They are on autosomes, but due to hormonal differences, are only expressed in one sex. |
front 17 What are sex influenced traits? | back 17 They occur on autosomes, are expressed in BOTH sexes, but
have |
front 18 True or false. Sex limited and sex influenced traits are different from sex linked traits | back 18 true |
front 19 What is penetrance? | back 19 It is the degree to which a genotype correlates with a phenotype |
front 20 What is fully penetrant traits? | back 20 The genotype always corresponds with the phenotype |
front 21 What are nonpenetrant traits? | back 21 They do not match genotypes and expected phenotypes. ex: when R is round and r is wrinkled, a rr plant is round |
front 22 What are incompletely penetrant traits? | back 22 Traits that sometimes match genotypes and phenotypes and sometimes don’t |
front 23 What is variable expressivity? | back 23 The same genotype can present in varying degrees. Ex: the NF1 traits with bumps |
front 24 What factors play a large role in certain genes being expressed? | back 24 Environmental and epigenetic factors |
front 25 What is gene environment interaction? | back 25 When the environment plays a role in regulating gene expression, which may contribute to this variable expressivity and incomplete penetrance |
front 26 What is pleiotropy? | back 26 where one genotype causes multiple different phenotypes at once. ex: sickle cell causing different symptoms |
front 27 What is polygenic inheritance? | back 27 occurs when multiple genotypes combine to code for one phenotype. ex: height being controlled by multiple gene interactions |
front 28 What are epistasis interactions? | back 28 when one gene alters the expression of another gene |
front 29 What are complementary gene interactions and its ratio? | back 29 Its when two genes together contribute to a given phenotype...(9:7 ratio) |
front 30 What are duplicate gene action and its ratio? | back 30 Occurs when two genes are redundant of one another and only one genotype is required to produce the same phenotype... (15:1 ratio) |
front 31 What are dominant gene interactions and its ratio? | back 31 occurs when a phenotype is present only when BOTH dominant
alleles |
front 32 What is recessive epistasis and its ratio? | back 32 when a homozygous recessive genotype in one gene masks the expression of the second gene, regardless of what it is...(9:3:4) |
front 33 What is dominant epistasis and its ratio? | back 33 when a dominant genotype in one gene masks the expression of the second gene, regardless of what it is...(12:3:1) |
front 34 What is dominant suppression and its ratio? | back 34 when one dominant allele suppresses another dominant allele...(13:3) |
front 35 What is genetic linkage? | back 35 It occurs when two genes are so close together, that their alleles segregate together instead of independently. It is a direct contradiction to Mendel’s law of independent assortment |
front 36 What are synthetic genes? | back 36 Genes on the same chromosome |
front 37 true or false. linked genes are always synthetic genes | back 37 true. (Genes that are closer together on the chromosome are typically more strongly linked together) |
front 38 Can synthetic alleles undergo crossing over? | back 38 yes |
front 39 What is nonrecombinant? | back 39 When the new chromosome contains the SAME alleles as originally (it looks like the parent chromosome) |
front 40 What is recombinant? | back 40 When the new chromosome contains DIFFERENT alleles than originally (it looks different than the parent chromosome) |
front 41 What is recombinant frequency? | back 41 It is how often linked genes recombine (undergo crossing over) |
front 42 true or false. The closer two linked genes are, the LESS they will crossover, and the smaller “r” will be | back 42 true |
front 43 is % r is equal to 1 map unit | back 43 yes |
front 44 what is the recombination frequency? | back 44 number of recombinants/ total number of progeny |
front 45 What organism do we use for test crossing? | back 45 a homozygous recessive organism. (important because only the recessive genes pass on) |
front 46 Under no genetic linkage what ratio should you see? | back 46 1:1:1:1 phenotypic ratio |
front 47 true or false. Under genetic linkage, you will see a much greater proportion of non-recombinant chromosomes | back 47 true |
front 48 What other factors affect recombination frequency? | back 48 species, age, sex, environment, temperature |
front 49 The homogametic sex has higher rates of what? | back 49 recombination across the WHOLE genome |
front 50 Recombination is favored by what? | back 50 natural selection (provides species with more genetic diversity) |
front 51 Does recombination happen at equal frequencies across the genome? | back 51 No (they have hotspots and coldspots) |
front 52 What are Variable Number Tandem Repeats (VNTR)? | back 52 a genetic marker short DNA sequences that repeat in a chromosomal region |
front 53 What are Single Nucleotide Polymorphisms (SNPs)? | back 53 It is one of the most common genetic markers. They are substitutions in a SINGLE base pair and each person has a unique set in their genome |
front 54 What are Restriction Length Fragment Polymorphisms (RFLP)? | back 54 genetic markers They are changes in where restriction enzymes cut DNA at SPECIFIC spots |
front 55 All of these genetic markers are inherited what? | back 55 codominantly |
front 56 Sometimes SNPs can be inherited together in a pattern known as a what? | back 56 haplotype (it occurs when the SNPs are linked) |
front 57 Why are haplotypes common in tracking ancestry? | back 57 Because a certain haplotype is more common in one ethnicity than another which is known as linkage disequilibrium |
front 58 What is lod score analysis? | back 58 the way we calculate the probability of two genes being linked |
front 59 The odds value is determined by what? | back 59 the likelihood CAUSED by linkage / likelihood by independent assortment |
front 60 What is the theta value? | back 60 the likelihood of linkage for recombination frequencies |
front 61 What does a theta value of 0 mean? | back 61 complete linkage |
front 62 What does a theta value of 0.5 mean? | back 62 complete independent assortment |
front 63 Scientist calculate a lod score form what? | back 63 the theta value |
front 64 If a lod score is >3, then what? | back 64 there is likely genetic linkage |
front 65 If a lod score is <-2, then what? | back 65 there is likely NOT genetic linkage |
front 66 If a lod score is <3 and >-2, then what? | back 66 the test is inconclusive |
front 67 What is a Genome Wide Association Study? | back 67 It finds influential genes across a genome (a gene that can influence a population) |
front 68 Why do we typically preform GWAs? | back 68 to look for known haplotypes across the genome |
front 69 GWAs are analyzed by what? | back 69 Manhatten plots (the higher a dot on a bar the stronger association between a gene and a disease) |
front 70 What are Mendelian genes? | back 70 They are caused by a single gene change. can be dominant or recessive, and is passed down through families. |
front 71 Chromosomal conditions results from? | back 71 changes in number of chromosomes, rearrangements, or changes in large sections of chromosomes |
front 72 Chromosomal conditions are caused by errors in what? | back 72 meiotic cell division |
front 73 What is carrier testing for? | back 73 Used in specific populations and for some prenatal tests. (those tested do not have symptoms) |
front 74 What is presymptomatic testing? | back 74 Testing for genetic conditions with late age of onset. Ex: Huntington’s Disease |
front 75 Newborn testing is required by who? | back 75 All US states and must be treated within a few weeks of life |
front 76 What does prenatal testing do? | back 76 detects genetic conditions in a fetus |
front 77 What are Chromosomal Territories? | back 77 The specific space in interphase where chromosomes are uncondensed and very active. |
front 78 What are Interchromosomal domains? | back 78 are spaces between territories where molecules like enzymes can move. Usually more gene rich chromosomes are closer to the nucleus |
front 79 Chromosome structure is visualized by what? | back 79 karyotypes |
front 80 Karyotypes identify chromosomes by what? | back 80 their size and shape. (p-short arm and q-long arm) |
front 81 How are banding patterns on chromosomes identified? | back 81 By Giemsa staining |
front 82 What are euchromatin? | back 82 Regions of chromosomes that are lighter stained. (they are less condensed and more active in gene transcription) |
front 83 What are heterochromatin? | back 83 Regions of chromosomes that stain darker. (They are less active in gene regulation and are more condensed) |
front 84 true or false. Chromatin can stay one or they other or can switch | back 84 true |
front 85 What is polyploidy? | back 85 occurs when there are 3+ sets of chromosomes in the nucleus of an |
front 86 What is autopolyploid? | back 86 occurs when there is a chromosomal set duplication within a species |
front 87 What is allopolyploid? | back 87 happens when chromosomes sets are combined from different species |
front 88 What does meiotic nondisjunction lead to? | back 88 diploid egg/sperm cells (results in a triploid organism) |
front 89 What does mitotic nondisjunction lead to? | back 89 doubles chromosome number |
front 90 What is hybrid vigor? | back 90 the increase in heterozygotes in hybrid lines. (Heterozygotes usually have better resistance to disease) |
front 91 true or false. Nondisjunction is different from polyploidy | back 91 true |
front 92 What does nondisjunction do? | back 92 It changes chromosome NUMBER, but not copies of chromosomes |
front 93 Nondisjunction in meiosis I does what? | back 93 creates a offspring that has monosomes or trisomies |
front 94 Nondisjunction in meiosis II does what? | back 94 only 2/4 gametes will be affected. 1 will be a trisomy, 1 will be
a |
front 95 Most nondisjunction in humans will not survive as humans, therefore they are sensitive to what? | back 95 gene dosage changes |
front 96 What is trisomy 21? | back 96 Down syndrome with 3 copies of chromosome. (Caused by the DSCR region of the chromosome) |
front 97 What is monosomy X? | back 97 Turner syndrome and there is only one X chromosome copy only found in females. There is Happloinsufficiency of SHOX gene |
front 98 How does uniparental disomy occur? | back 98 when both chromosome copies are from the same parent |
front 99 What is a break point on a chromosome? | back 99 when BOTH strands of DNA break at a given point |
front 100 Terminal deletions occur where? | back 100 At the end of the chromosome and include the telomeres |
front 101 Interstitial deletions occur where? | back 101 In the MIDDLE of a chromosome and require 2 break points |
front 102 Whenever a chromosome fragment loses its centromere it becomes what? | back 102 acentric |
front 103 Duplications and deletions can happen at what level? | back 103 micro and macro |
front 104 What happens at the Macro level? | back 104 whole gene duplication, section of a chromosome deletion |
front 105 What happens at the micro level? | back 105 single nucleotide deletion, gene fragment duplication. (the only possible detection is FISH staining) |
front 106 What does unequal crossing leave us with what type of chromosome? | back 106 one recombinant chromosome with a duplication and the other recombinant chromosome with a deletion |
front 107 When can inversions occur? | back 107 when a DNA sequence flips and is read backwards. Ex: the sequence ABCDE can become AEDCB |
front 108 What is paracentric inversion? | back 108 inversions that occur ONLY on one arm of the chromosome and do not involve the centromere |
front 109 What is pericentric iinversions? | back 109 They are inversions occurring across BOTH arms of the chromosome and involve the centromere |
front 110 What is Nonreciprocal Translocations? | back 110 happen when a piece of DNA from one chromosome breaks off and attaches to a different chromosome |
front 111 What is Reciprocal Translations? | back 111 occur when pieces of DNA from TWO different chromosomes swap placed. (can play a large role in infertility) |
front 112 What is Robertstonian Translocations? | back 112 occur when two chromosomes fuse together (therefore the total number of chromosomes in the cell will drop) |
front 113 In Eukaryotes, DNA is bound and organized by what? | back 113 histone proteins |
front 114 What are nucleosomes? | back 114 The complex the DNA wraps around a histone octomer to form |
front 115 What is the nucleosome core comprised of? | back 115 2 H2A proteins, 2 H2B proteins, 2 H3 proteins, and 2 H4 proteins |
front 116 What is a chromatosome? | back 116 When the H1 histone protein binds to the nucleosome DNA and the complex is formed |
front 117 What is linker DNA? | back 117 Chromatosomes that are separated by short pieces of DNA |
front 118 What is a solenoid? | back 118 When chromatin further condenses to form a 30nm fiber |
front 119 Why is the chromatin organization important? | back 119 Chromatin condensation helps regulate gene expression, and forming the chromosome shape helps equal chromosome separation in cell division |
front 120 What is metacentric? | back 120 the middle of the chromosome |
front 121 What is submetacentric? | back 121 the centromere is between the center and tip |
front 122 Arocentric? | back 122 the centromere is close to the end. "satellite" |
front 123 What is telocentric? | back 123 The centromere is at the tip of the chromosome and there is no p arm |
front 124 What are the histone proteins? | back 124 H1, H2A, H2B, H3, H4 H1 is not on the nucleosome |
front 125 BRCA1 and BRCA2 mutations increase the risk for what? | back 125 breast and ovarian cancer |
front 126 Bayeson analysis determines what? | back 126 probability of a certain genotype in a family |
front 127 What is a Mendelian condition? | back 127 caused by mutation of a single gene and has 6 patterns of inheritance |
front 128 What are the observed 6 patterns of inheritance? | back 128 autosomal dominant, autosomal recessive, X-linked
dominant, |
front 129 What is a chromosomal condition? | back 129 caused by an extra chromosome, a missing chromosome, duplication or deletion of a chromosome segment. Usually, a result of new mutation in meiotic division. An example is trisomy 21 (down syndrome) |
front 130 What are multifactorial conditions? | back 130 influenced by multiple genes along with environmental factors; diabetes is an example |
front 131 What are indicators for genetic testing? | back 131 previous child with a genetic or chromosome condition, family history of a genetic or chromosome condition, advanced maternal age or other indicator of elevated risk in pregnancy, fetal exposure to a toxic or harmful compound, prolonged infertility or repeated pregnancy loss, new diagnosis of a genetic or chromosome condition, consultation for pre- or -postgenetic or chromosome test risk assessment |
front 132 What are the goals of genetic counseling? | back 132 Provide comprehensive information before or after a genetic tests, explain risk recurrence, identify the beliefs, values, and relationships that are affected, and provide referrals to support groups or services. |
front 133 Four areas of investigation that are affected by the collection of personal genetic or genomic information. | back 133 Genetic Research, Genetic Health Care, Societal Issues of Genetics and Genomics, Legal, Regulatory, and Public Policy Issues |
front 134 Genetic Counseling and Ethical Issues | back 134 Prenatal genetic and chromosome testing, Newborn genetic screening, and Testing for genetic predisposition |