Lesson 6: Mutations

Question 1

Mutation

Answer 1

A permanent change in the genetic material of an organism
- all mutations are inheritable
— not all mutations are passed on to future generations

Question 2

Cell Mutation: Germ Cell

Answer 2

Mutations to the information on reproductive cells, and will be passed on to offspring

Question 3

Cell Mutation: Somatic Cell

Answer 3

Mutations are passed on to daughter cells in the body but not to offspring.

Question 4

Types of Mutation 1: Point Mutations

Answer 4

A mutation in which one nucleotide in a DNA sequence is replaced by anoter nucleotide which often occurs with a substitution

Question 5

Point Mutations Consequences: Silent Mutation

Answer 5

This mutation has no effect on the cell’s metabolism and how proteins are assembled

Question 6

Point Mutations Consequences: Mis-Sense Mutation

Answer 6

The substitution leads to an altered but functioning protein

Question 7

Point Mutations Consequences: Nonsense Mutation

Answer 7

The substitution erases a start sequence or inserts a stop sequence

Question 8

Types of Mutation 2: Frameshift Mutations

Answer 8

A type of point mutation in which one or more nucleotides are inserted or deleted from the DNA sequence, often resulting in non-sense mutations.
— these types of mutations cause the reading frame of a gene to be altered

Question 9

Types of Mutation 3: Chromosomal Mutations

Answer 9

With its results being the restructuring of the DNA sequence, these are mutations that affect more than one gene on one or more chromosomes
—Portions of chromosome can be lost/gained during cross-over in meiosis or DNA replication

Question 10

Causes of Mutations: Spontaneous Mutations

Answer 10

Mutations that arise as a result of the natural processes of the cell

Question 11

Causes of Mutations: Induced Mutations

Answer 11

Mutations that are caused by factors outside the cell

Question 12

Mutagen

Answer 12

A substance/event that increases the rate of mutation in an organism; can be either physical or chemical

Question 13

Physical Mutagens

Answer 13

High energy radiation via X rays and gamma rays tears through a DNA strand causing random changes in the nucleotide sequence. This causes mutations ranging from the deletion of just a few nucleotides to the loss of large portion chromosomes.
— High energy radiation is the most damaging form of mutagen known

Question 14

Physical Mutagens: UV Radiation

Answer 14

has lower levels of energy although still a strong mutagen. It most likely affects pyrimidine bases that are adjacent to e/o by bonding them covalently to form a larger molecule called a dimer

Question 15

Physical Mutagen: UV Radiation Consequences

Answer 15

Distortion of the bases interferes with DNA replication, often causing cancer.

Question 16

Chemical Mutagens

Answer 16

A molecule that can enter the cell nucleeus and induce mutation by reacting chemically with DNA.
—May act by inserting themselves into the DNA molecule causing a frameshift mutation
-May have a structure similar to ordinary nucelotides but w/ different base pairing properties