Chapter 15

Question 1

Mutation

Answer 1

A heritable change in the genetic material

Question 2

Point mutation affects?

Answer 2

A single base pair.

Question 3

2 basic alterations

Answer 3

Change base sequence
Add or remove nucleotides

Question 4

Silent mutation

Answer 4

Doesn’t alter the amino acid sequence

Question 5

How many codon per amino acid?

Answer 5

More than 1

Question 6

Missense mutation

Answer 6

Changes a single amino acid in a polypeptide

Question 7

Nonsense mutation

Answer 7

Change from a normal codon to a stop or termination codon

Question 8

Frameshift mutation

Answer 8

Addition or deletion of nucleotides that are not multiples of 3

Question 9

Mutation outside of coding sequences

Answer 9

Mutation may alter DNA operator sequence so that repressor protein doesn’t bind

Question 10

Germ-line cells mutation

Answer 10

Rise to gametes
Can occur in sperm/egg cells or the cells that gives rise to eggs & sperm

Question 11

Somatic cell mutation

Answer 11

All other cells
Can occur early/late in development

Question 12

Spontaneous mutation

Answer 12

Result from abnormalities in biological processes
DNA polymerase adds wrong nucleotide.

Question 13

How many spontaneous mutation

Answer 13

1 mutation for every 1 million genes.

Question 14

Induced mutation

Answer 14

Brought on by environmental agents

Question 15

Mutagens

Answer 15

Chemical/physical agent can alter DNA in various ways.

Question 16

Disrupt pairing by

Answer 16

Modifying nucleotide structure
Base analogue mutagens similar to particular bases cause errors in replication
Alkylating bases

Question 17

Interfering with replication

Answer 17

Benzopyrene (auto exhaust) inserts between bases & distort the helix causing errors

Question 18

Ionizing radiation

Answer 18

Have high energy & short wavelength
X Pay & gamma Rays

Question 19

What can lonizing radiation do?

Answer 19

Can penetrate deeply into biological materials to create free radicals.

Question 20

Free radicals

Answer 20

Unstable molecule that can build up in cell & cause damage in other molecule

Question 21

Why lionizingradation can penetrate biological materials?

Answer 21

Cause base deletions or breaks in 1/both DNA strands

Question 22

Base deletion

Answer 22

A mutation in which a part of a chromosome or a sequence of DNA is left out during DNA replication

Question 23

Nonionizing radiation

Answer 23

Has less energy & can only penetrate the surface
Uv Rays

Question 24

What does Wrays causes

Answer 24

A formation of thymine diner causing gaps or incorporation of incorrect bases

Question 25

Ames test

Answer 25

Test ability of substance to cause mutation

Question 26

DNA repair

Answer 26

Living orgs must have the ability to repair changes that occurs in DNA in order to minimize mutation

Question 27

What requires for DNA repair

Answer 27

DNA damage be detected Repair of DNA damage

Question 28

Direct repair

Answer 28

Enzyme removes a modification Altered DNA strand removed & new sequent synthesized

Question 29

Nucleotide excursion repair (ner)

Answer 29

Recognizes abnormal base Region encompassing several nucleotides in the damaged strand is removed from the DNA Intact undamaged strand is used as a template for resynthesis of a normal complementary strand. Fixes many mutation.

Question 30

How ner was discovered in human?

Answer 30

By the analysis of genetic diseases that have defective ner based DNA repair.

Question 31

Cancer

Answer 31

Multicellular Disease organisms that is characterized by uncontrolled cell division.

Question 32

Carcinogens

Answer 32

Agents that increase the likelihood of developing cancer

Question 33

Invasive

Answer 33

Can invade healthy tissue

Question 34

Metastatic

Answer 34

Can migrate to other parts of the body.

Question 35

Proto-oncogene

Answer 35

Mutation causes this gene to be overactive Called an oncogene Involved in cell growth

Question 36

Tumor-suppressor gene

Answer 36

Normal y this gene encodes a protein that prevents cancer

Question 37

Missense mutation

Answer 37

Chemical mutagens have been shown to cause missense mutation leading to cancer.

Question 38

Gene amplification

Answer 38

Abnormal increase in copy number results in foo much of encoded protein

Question 39

Chromosomal translocations

Answer 39

2 different chromosome break & the ends of broken chromosome fuse with each other incorrectly.

Question 40

Retroviral insertion

Answer 40

Viral DNA may insert into a host chromosome in such a way that a viral promoter & response elements are next to a proto- oncogene

Question 41

Cyclin-dependent protein kinases (CDKS)

Answer 41

Responsible for advancing a cell through the four phases of the cell cycle

Question 42

3 ways to loss of tumor-suppressor gene

Answer 42

Mutation occurs specifically within a tumor- suppressor gene to inactivate it's function Chromosome loss may contribute if the missing chromosome carries 1/more tumor- suppressor genes Abnormal methylation of CpG islands near promoter regions