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Biotech quiz 1
Question | Answer |
---|---|
chromosome Theory of inheritance | mendellian genes have specific loci along chromosomes, and it is the chromosomes that undergo segregation and independent assortment |
wild type | phenotype fro a charecter most commonly observed in natural populations |
mutant type | traits that are alternative to the wild type |
which one of mendel's laws describes the inheritance of alleles for a single charecter? Which law relates to the inheritance of alleles for 2 charecters in a diihybrid cross? | The law of segregation for single charecter alleles The law of independent assortment for allle;es with 2 charecters |
sex linked gene | a gene located on either sex chromosome |
x linked gene | the 1100 genes on a x chromosome |
Duchenne Muscular therapy | x linked disorder that weakens muscles and causes loss of coordinaation |
hemophilia | prolonged bleeding caused by the absence of one or more proteins needed for blood clotting |
Barr body | inactive x in female cells |
linked genes | genes located near each other on the same chromosome tend to be inherited together in gentietic crosses. |
linked genes vs sex linked gene | 2 or more genes on the same chromosome vs a single gene on a sex chromosome |
genetic recombimnation | the production of offspring with combinations of traits that differ from those found in either P generation par |
parental types | inherit a phenotype that matches either of the phenotypes of the P (parental) generation originaliy crossed to produce the Fj dihybrid |
recombinant types | |
crossing over | a set of proteins orchestrates an exchange of corresponding segments of one maternal and one paternal chromatid |
genetic map | an ordered list of the genetic loci along a chromosome first done by sturtevant |
linkage map | a genetic map based on recombination frequencies |
when 2 genes are located on the same chromosome, what is the physical basis for the production of recombinant offspring in a testcross between a dihybrid parent and a double mutant recessive parent? | offspring with recombinant gametes arise from fertiliaztion of recombo gametes by homozygous recesive gametes from double mutant parent |
nondisjunction | members of a pair of homolougous chromosomes do not move apart properly during meiosis 1 or sister chromatids fall apart during meiosis 2. |
aneuploidy | |
monosomic | 2n-1 |
trisomic | 2n+1 |
deletion | chromosomal fragment is missing, a deletion removes a chromosomal segment Ex: abce |
duplication | a chromosomal segment from another chromosome is attached to a chromosome with that segment already in place causing a repition in the structure EX: aBCBCde |
inversion | a chromosomal segment is placed in a chromosome in the wrong order EX: aDCBe |
Translocation | nonhomologous chromosome exchange fragment EX: MNOcde ABpqrs |
Down Syndrom | anueploid condition caused by an extra chromosome 21 |
genomic imprinting | |
A man with hemophelia (recesive sex linked gene) has a daughter without the condition. She marries a man who does not have hemophelia. What is the probability that their daughter/son have hemophelia? If they have 4 sons? | |
dystrophy is an inherited disorder it is seen mostly in boys born to unaffectected parents and ussually results in death in early teens. Is this disorder caused by dominant or recisseive alllele? is it sex linked or autosomal? Why is it not seen in girls | |
a wild type fruit fly (hetero, gray, normal wings) fucks a black fly with tiny wings. | |
What charecteristic of the sex chromosome allowed MOrgan to correlate thier behaviour with that of the alleles of the eye color gene | |
why are males affected by xlinked disorders much more often than females | Males have only one X chromosome, along with a Y chromosome, while females have two X chromosomes |
why are specific alleles of 2 distant genes more likely to show recombination than those of 2 closer genes | Crossing over is a random occurrence, and the more distance there is between two genes, the more chances there are for crossing over to occur |
why are invesions and reciprical translocations less likely to be lethal than are aneuploidy, duplicaitons, deletions, and nonreciprocal translocations? | inversions: total genetic infromation stays the same so no phenotypic consequences |
Explain how genomoic imprinting and inheritance ofm mitochondrial and chloroplast dna are exceptions to standard mendelliian inheritance | |
sry | gene region present on the y chromosome that triggers male development |
wnt4 | gene region present on the x chromosome that triggers female development |
males are more often affected by sex linked traits than females because | males are hemizygous for the X chromosome |
3 genes at 3 loci are being mapped in a species. Each has 2 phenotypes, 1 which is markedly different from the wild type. The unusual allele of the first gene is inherited with either of the others 50% of the time. But the unusual alleles of the other 2 | the first gene is assorting independently from the other 2 that are linked |
if nondisjunction occurs in meiosis 2 during gametogenisis, what will be the result at the the completion of meiosis | 1/4 of the gametes will be n+1, 1/4 will be n-1, and 1/2 will be n |
a couple has a child with down syndrome. The mother is 38 years old at the time of delivery. What is the most probable cause of the child's condition | one member of the couple underwent nondijunction in somatic cell production |
Barr body is normally found in which kind of human cell | |