Chapter 11

Question 1

Activators

Answer 1

A protein that switches on a gene or group of genes by binding to DNA.

Question 2

Adult Stem Cells

Answer 2

A cell present in adult tissues that generated replacements for nondividing differentiated cells.

Question 3

Alternative RNA splicing

Answer 3

A type of regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns.

Question 4

Carcinogens

Answer 4

A cancer-causing agent, either high energy radiation or a chemical.

Question 5

Cellular Differentiation

Answer 5

Specialization in the structure and function of cells that occurs during the development of an organism; results from selective activation and deactivation of the cells’ genes.

Question 6

Complementary DNA (cDNA)

Answer 6

A DNA molecule made in vitro using mRNA as a template and the enzyme reverse transcriptase.

Question 7

DNA microarray

Answer 7

A glass slide containing thousands of different kinds of single-stranded DNA fragments arranged in an array. Tiny amounts of DNA fragments, representing different genes, are attached to the glass slide. These fragments are tested for hybridization with various samples of cDNA molecules, thereby measuring the expression of thousands of genes at one time.

Question 8

Silencers

Answer 8

A eukaryotic DNA sequence that inhibits the start of gene transcription.

Question 9

Therapeutic Cloning

Answer 9

The cloning of human cells by nuclear transplantation of therapeutic purposes, such as the replacement of body cells that have been irreversibly damaged by disease or injury.

Question 10

Operator

Answer 10

In prokaryotic DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach. The binding of the repressor prevents RNA polymerase from attaching the promoter and transcribing the genes of the operon.

Question 11

Operon

Answer 11

A unit of genetic regulation common in prokaryotes ; a cluster of genes with related functions along with the promoter and operator that control their transcription

Question 12

Promoter

Answer 12

A specific nucleotide sequence in DNA, located at the start of the gene, that is the binding site for RNA polymerase and the place where transcription begins

Question 13

Proto-oncogene

Answer 13

A normal gene that can be converted to a cancer causing gene

Question 14

Regeneration

Answer 14

The regrowth of body parts from part of an organism

Question 15

Repressor

Answer 15

A protein that blocks the transcription of a gene or operon

Question 16

Reproductive Cloning

Answer 16

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals

Question 17

Signal Transduction Pathway

Answer 17

A series of molecular changes that convert a sign on the surface of a target cell to a specific response on the interior of the cell

Question 18

X Chromosome Inactivation

Answer 18

In female mammals, the Inactivation one of the X chromosome in each somatic cell. Once X Inactivation occurs in a given cell, all decedents of that cell will have the same copy of the X chromosome inactivated. (inactivation of an unexpressed gene)

Question 19

embryonic stem cells(ES Cells)

Answer 19

any of the cells in the early animal embryo that differentiate during development to give rise to all the kinds of specialized cells in the body

Question 20

Enhancers

Answer 20

a eukaryotic cell DNA sequence that helps stimulate transcription of a gene some distance from it. An enhancer functions by means of a transcription factor called an activator, which binds to it and the rest of the transcription apparatus.

Question 21

gene expression

Answer 21

the process whereby genetic information flow from genes to proteins, the flow of genetic information from genotype to phenotype: DNA to RNA to Protein

Question 22

gene regulation

Answer 22

the turning off and on of specific genes within a living organism

Question 23

growth factors

Answer 23

a protein secreted by certain body cells that stimulates other cells to divide

Question 24

homeotic genes

Answer 24

a master control gene that determines the identity of a body structure of a developing organism, presumably by controlling the developmental fate of groups of cells. (In plants such genes are called organ identity genes

Question 25

nuclear transplantation

Answer 25

a technique in which the nucleus of one cell is placed into another cell that already has a nucleus or which the nucleus had previously been destroyed. the cell is then stimulated to grow, producing an embryo that is a genetic copy of the nucleus donor

Question 26

oncogene

Answer 26

a cancer causing gene, usually contributes to malignancy by abnormally enhancing the amount of activity of a growth factor made by the cell

Question 27

transcription factors

Answer 27

in eukaryotic cell, a protein that functions in initiating or regulating transcription. Transcription factors bind to DNA or other proteins that bind DNA

Question 28

tumor-suppressor genes

Answer 28

a gene whose product inhibits cell division, thereby preventing uncontrolled cell growth