Mutations 2D

Question 1

Deletion

Answer 1

occurs in a broken segment is lost from a chromosome

Question 2

Duplication

Answer 2

A segment is broekn rom one chromosome and inserted to its homologue

Question 3

Translocation

Answer 3

Occurs if a broken segment is attached to a diferent nonhomologous chromosome

Question 4

Inversion

Answer 4

Occurs if a broken segmet re-attaches to the same chromosome from which it was lost but in reversed orientation so that the order of genes is reversed

in one chromatid

Question 5

Inorder to be inherited by offsprings, chromosomal alterastions must occur

Answer 5

in cells of the germ line leading to devlopment of eggs or sperm

Question 6

When can duplications arise

Answer 6

during recombination in meiosis if crossing over occurs unequally so that a segment is deleted from one chromosome of a homologous pair and inserted into the other

Question 7

In many cases, a transloaction is_____ meaning that……

Answer 7

reciprical

two nonhomologous chromosomes exchange segments

Question 8

reciprical translocations resemble ***** except that the two chromosomes invloved in the exchange **

Answer 8

genectic recombination

do not contain the same genes

Question 9

Inversions have the same affects as

Answer 9

translocations

Question 10

Missense mutation

Answer 10

A sense codon is changed to a different sense codon that specifies a different amino acid.

Question 11

Nonsense mutation+what happens in translation

Answer 11

A sense codon is changed to a stop codon. Translation of an mRNA containing a nonsense mutation results in a shorter than normal polypeptide that in many cases will be only functionally partially at best.

Question 12

Silent mutations

Answer 12

A sense codon is changed to a diferent sense codon but that codon still specifies the same amino acid so the function of the polyptide is the same.

Question 13

frameshift mutation+ what about resulting polypeptide?

Answer 13

A single base pair deletion or insertion in the coding region of a gene alters the reading frame of the resulting mRNA.

The resulting polypeptide is usally nonfunctional because of the signifigantly altered amino acid sequence.

Question 14

Mutations

Answer 14

Changes in double stranded sequence of bases in genetic material

Question 15

Spontaneous mutations

Answer 15

changes in DNA due to errors in replication and repair

Question 16

Thymine dimers

Answer 16

Thymine bases that are side by side in a chromosome become linked together covalently, Attempts to fix the dimers can lead to mutations.

Question 17

somatic mutations are usually expressed as

Answer 17

sectors

If a mutation occurs in one of the progenitor cells, all of its daughter cells will also express the mutation. For this reason, somatic mutations generally appear as a sector on the mutated individual.

Question 18

transitions

Answer 18

a point mutations that changes purine to another purine or pyrimidine to another pyrimidine

Question 19

Transversions

Answer 19

Point mutation of purine to pyrimidine or pyrimidine to a purine change.

Question 20

Frameshift mutation

Answer 20

insertion or deletion of a small number of base pair that alter reading frame. Unless in mutations of threes

Question 21

spontaneous lesions

Answer 21

Depurination and deamination (*cytosine lose amine group and becomes uracil) of bases

Question 22

Induced

Answer 22

natural environment or articifial agent or mutagen