MUTATIONS, CHROMOSOMAL ABBERATIONS, ETC. Flashcards
Involves a whole set of chromosome, homologous chromosomes, single chromosomes, or segments of a chromosome
CHROMOSOMAL MUTATIONS
affects genome structure or chromosome structure
CHROMOSOMAL MUTATIONS
Changes that involves the whole genome or entire set of chromosomes
EUPLOIDY
Organism with cells containing 3 or more sets of chromosomes
POLYPLOIDS
Polyploidy is due to multiplication of one genome
AUTOPOLYPLOID
Involves multiple sets of genome that are not identical
ALLOPOLYPLOID
Occurs when one or more chromosomes of a normal set are lacking or are present in excess
ANEUPLOIDY
Trisomy 21 is an example of ———–, having an excess chromosome in chromosome no. 21
CHROMOSOMAL ANEUPLOIDY
The failure of tetrads to separate during anaphase I leads to
Nondisjunction in Meiosis I
The failure of sister chromatids to separate during the anaphase II
Nondisjunction in Meiosis II
Loss of a segment of the chromosome
DELETION
A single break on the terminal ends of the chromosome
Terminal deletion
The loss of the segments in between the chromosome; two breaks and reattachment of the outer pieces
INTERSTITIAL DELETION
When a section of the chromosome is in excess of the normal amount
Duplications or repeats
The rotation of a chromosome segment to a full 180 degrees
INVERSIONS
When one segment of a chromosome becomes attached to a different chromosome or to a different part of the same chromosome
TRANSLOCATION
Occurs when a single piece of chromosome is attached to another chromosome
SIMPLE TRANSLOCATION
fertile, because the potential exists for equal segregation of homologs during meiosis
EVEN-NUMBER POLYPLOIDS
Have unpaired chromosomes; rare balanced gametes; sterile
ODD-NUMBER POLYPOIDS
caused by natural processes in cells
spontaneous mutation
caused by interaction of DNA with a mutagen
Induced mutation
bases that are similar enough to the standard bases to be incorporated into nucleotides during DNA replication
Base analogs
It causes point mutations
Chemical mutagen
TRUE OR FALSE
5-bromouracil is an analog of A
FALSE, it is an analog of T
TRUE OR FALSE
2-aminopurine is an analog of A
TRUE
Intercalation causes insertion during DNA replication
Intercalating agents
UV radiation, Ionizing radiation and heat are characterized as
Physical mutagen
mobile pieces of DNA that can move from one location in a genome to another
Transposons or transposable elements
Changes in genetic material - changes in DNA code - thus change in a gene
Mutations
the DNA code will have a base(or more) missing, added, or exchanged in a codon
gene mutations
TRUE OR FALSE
Only mutations in gametes (egg and sperm) are passed onto offspring.
TRUE
TRUE OR FALSE
Mutations in body cells only affect the organism in which they occur and are not passed onto the offspring.
TRUE
Occurs when a base sequence of a codon is changed.
POINT MUTATIONS
3 TYPES OF POINT MUTATIONS
Substitution
Deletion
Insertion
A single nitrogen base is substituted for another codon. It may or may not affect the amino acid or protein.
SUBSTITUTION MUTATIONS
A nitrogen base is inserted/ added to the sequence. It causes the triplet frames to shift. Always affects the amino acids and proteins.
INSERTION MUTATIONS
A nitrogen base is deleted or removed from the sequence. It causes the triplet frames to shift. Always affects the amino acids and proteins.
DELETION MUTATIONS
Has the least effect because it changes only one amino acid or it may change no amino acid.
SUBSTITUTION
TRUE OR FALSE
Sickle cell anemia is an example of substitution mutations.
TRUE
Huntington’s disease is an example of substitution mutations, wherein a nitrogenous base is inserted to the sequence.
FALSE, it is an example of insertion mutation
A genetic mutation where a single nucleotide base is changed, inserted or deleted from a sequence of DNA or RNA.
POINT MUTATIONS
Mutations in DNA that do not have an observable effect on the organism’s phenotype. Specific type of neutral mutation.
Silent Mutations
A change in one DNA base pair; the altered DNA sequence prematurely signals the cell to stop building the protein; results in a shortened protein that may function improperly
NONSENSE MUTATION
Change in one DNA base pair that results in the substitution of one amino acid for another in the protein made by a gene.
MISSENSE MUTATIONS
This type of mutation occurs when addition or loss of DNA bases changes a gene’s reading frame. It shifts the groupings of these bases and changes the code for amino acid.
FRAMESHIFT MUTATION
resulting protein is non-functional
removal of a piece of DNA
DELETION
addition of a piece of DNA
insertion
types of chromosomal mutations
Deletion
Inversion
Duplication
Translocation
changes that often occurs during meiosis
chromosomal mutations
one or more nucleotides are lost or deleted from the chromosome
deletion
a portion of a genetic material or chromosome is duplicated or replicated
DUPLICATION
results from an unequal crossing over between misaligned homologous chromosomes during meiosis
duplication
a portion of a chromosome is relocated, and incorporated into a different chromosome
TRANSLOCATION