Chapters 11-13 Flashcards Preview

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Flashcards in Chapters 11-13 Deck (107)
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1

Gene regulation

the turning on and off of genes
-gene being turned on: being transcribed into mRNA and translated into specific protein molecules
-can help organisms respond to environmental changes.

2

gene expression

the overall process by which genetic information flows from genes to proteins (from genotype to phenotype)

3

Prometer

a control sequence at a site where the transcription enzyme, RNA polymerase, attaches and initiates transcription

4

operator

between the promoter and the enzyme genes
-DNA control sequence that acts as a switch
-determines whether RNA polymerase can attach to the promoter and start transcribing the genes

5

operon

a cluster of genes with related functions and the control sequences

6

What is the key advantage to the grouping of related genes into operons?

A single "on-off switch" can control the whole cluster.

7

How is transcription turned off?

a protein called a repressor binds to the operator and physically blocks the attachment of RNA polymerase to the promoter.

8

regulatory gene

-located outside the operon
-codes for the repressor
-expressed continually, so the cell always has a small supply of repressor molecules

9

activators

proteins that turn operons on by binding to DNA and stimulating gene transcription

10

differentiation

what individual cells must undergo to become specialized in structure and function, with each type of cell fulfilling a distinct role.

11

histones

A chromosome contains DNA wound around clusters of small proteins
-account for about half of the mass of eukaryotic chromosomes

12

nucleosome

"bead" that consists of DNA wound twice around a protein core of eight histone molecules

13

epigenetic inheritance

inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence

14

x chromosome inactivation

-a specific gene on the X chromosomes ensures that only one of the chromosomes will be inactivated
-initiated early in embryonic development when one of the two X chromosomes in each cell is inactivated at random

15

Barr body

inactive X in each cell of a female condenses into a compact object

16

alternative RNA splicing

an organism can produce more than one type of polypeptide from a single gene
-may generate two or more types of mRNA from the same transcript.

17

opportunities for regulation of gene expression

-breakdown of mRNA
-initiation of translation
-protein processing

18

microRNAs

small single-stranded RNA molecules
-can bind to complementary sequences on mRNA molecules

19

small interfering RNAs

-similar in size and function to miRNAs

20

RNA interference

blocking of gene expression by siRNAs

21

homeotic gene

master control gene that regulates groups of other genes that determine the anatomy of parts of the body.

22

nucleic acid hybridization

the base pairing of one strand of a nucleic acid to a complementary sequence on another strand

23

DNA microarray

consists of tiny amounts of a large number of different single-stranded DNA fragments

24

signal transduction pathway

series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell.

25

totipotent

capable of producing every kind of specialized cell in the organism

26

regeneration

the regrowth of lost body parts

27

nuclear transplantation

DNA from a donor cell is inserted into a nucleus-free host egg, resulting in a clone of the DNA donor.

28

therapeutic cloning goal

produce ES cells to treat disease

29

oncogene

a gene that can cause cancer when present in a single copy in the cell

30

proto-oncogene

a normal cellular gene that helps control cell division that has the potential to become an oncogene