Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
mutations
biol 1210
| Question | Answer |
|---|---|
| mutation | any permanent change in an organism's DNA |
| different types of mutations | small-scale mutation (point mutations) - 1 or small # of base changes in DNA; alterations in chromosomes structures - large-scale changes in chromosome bases; alterations in chromosome # - non-disjunction during meiosis |
| causes of mutations | spontaneous mutations - errors in DNA replication or cell division; induced mutations - by mutagens (radiation or chemicals) |
| consequences of mutations | beneficial mutations increase fitness; neutral mutations do not effect fitness; deleterious mutations decrease fitness. Most are neutral or deleterious |
| fitness of an organism | refers to an organism's survival & reproductive success for viable offspring (viable - can also reproduce) |
| base-pair substitution mutations | occur when a mistake during DNA synthesis or DNA repair results in different base at a particular location on the gene |
| silent mutation | substitution mutation, no effect on the amino acid produced by a codon due to the redundancy of the genetic code (ex. same 1st 2 codons, if change 3rd base it doesn't have effect) |
| missense mutation & 2 examples | substitution mutation, code for different amino acid. Ex. sickle cell, changes Glu (A) -> Val (T) in hemoglobin, deleterious & Himalayan mice & minks, changes HIs -> Arg or Gln |
| nonsense mutation | substitution mutation, changes an amino acid codon into a stop codon |
| truncated polypeptide | results from nonsense mutation. Almost all r nonfunctional & unstable |
| insertion/deletion mutation | small-scale mutation - additions/losses of nucleotide pairs in a gene. Have disastrous effect on resulting protein (worse than substitutionts) |
| frameshift mutation | an alteration to the codon reading frame due to some insertion/deletion mutations that drastically changes the protein produced |
| does insertion/deletion mutation always result in frameshift mutation? | no, if a nucleotide triplet is removed/added in the correct reading frame then it would add/delete one whole amino acid from the polypeptide |
| chromosome alteration - inversion | a segment of a chromosome breaks off, flips around & rejoins the same chromosome |
| chromosome alteration - translocation | a section of a chromosome breaks off & becomes attached to another chromosome, often as a reciprocal translocation (like crossing over) |
| chromosome alteration - duplication | a segment of a chromosome is present in multiple copies. duplication & divergence results in formation of new genes from duplications of old ones |
| gene family | a group of genes with related functions, may stem from multiple rounds of duplications & divergence, ex. olfactory receptors in animals |
| chromosome alteration - deletion | a segment of a chromosome is lost |
| chromosome # alteration - nondisjunction | occurs if both homologs or both sister chromatids move to the same pole of the parent cell (most impactful during meiosis). Results in gametes that contain an extra chromosome (n + 1) or lack a chromosome (n - 1) |
| is nondisjunction more impactful if it occurs during meiosis I or meiosis II? | meiosis I - results in 4 mutated gametes and hence a higher probability of monosomy/trisomy |
| trisomy | occurs with fertilization of a n + 1 gamete |
| monosomy | occurs with fertilization of a n -1 gamete |
| aneuploid | refers to cells with too many or too few of a chromosome (autosome or sex chromosome) |
| genetic origin of down syndrome & represent for male & female | autosomal disorder. F - 47, XX, +21. M - 47, XY, +21 |
| describe results of fertilization of gametes (egg + sperm): O + Y, O + X, XX + Y, XX + X. Which are monosomy, which are trisomy? | YO - Not viable (miscarriage), XO - Turner syndrome, XXY - Klinefelter syndrome, XXX - Triple X syndrome. Monosomy - YO, XO, trisomy - XXY, XXX |
| genotype + phenotype for phenylketonuria | recessive mutation in phenylalanine metabolizing gene. Impaired brain function w mental & physical retardation |
| genotype + phenotype for albinism | recessive mutation in melanin synthesizing genes. Lack of pigmentation in skin, eyes & hair |
| genotype + phenotype for Tay-Sachs disease | recessive mutation in ganglioside metabolizing gene. Severe & lethal neurodegeneration |
| genotype + phenotype for Huntington's disease | dominant mutation in a gene of unclear function. Neurodegeneration w motor & cognitive impairment |
| genotype + phenotype for Down syndrome | 47, XX, +21 or 47, XY, +21. Mental & physical retardation, sterility |
| genotype + phenotype for Turner syndrome | 45, XO. impaired sexual development, sterility |
| genotype + phenotype for Klinefelter syndrome | 47, XXY. Impaired sexual development, sterility |
| polyploidy & Ex. describe the process | more than 2 chromosome sets in the genome of an organism. Ex. plant exposed to chemicals that induce total nondisjunction in meiosis -> diploid gametes fertilize -> tetraploid plant is produced |
Created by:
AntBanana
Popular Biology sets