AP Biology Development/Gene Control/Gene Expression/Biotechnology Chapters 18-21

differential gene expression

The process by which cells with the same DNA express different genes, leading to diverse cell types and functions during development.

transcription

The point where Expression of specific genes is most commonly regulatedin the process of converting DNA to RNA.

histone acetylation

Mechanism for gene expression that opens up the chromatin structure, making DNA accessible for transcription

DNA methylation

Mechanism of Gene Expression where addition of methyl groups on DNA bases inhibits transcription and can silence gene expression.

Transcription factors

Mechanism of regulation Gene Expression when proteins bind to non-coding segments of DNA called control elements

enhancers

Segment of eukaryotic DNA containing multiple control elements, usually located far from one gene whose transcription is regulated for gene expression

activators

Protein that binds directly to promoter in prokaryotes and to control elements in enhancers in eukaryotes and stimulates gene transcription for gene expression.

repressors

Protein that inhibits gene transcription by binding to the operator or silencer regions of DNA, preventing the binding of RNA polymerase.

Coordinately controlled genes

Group of genes of related function that need to be turned on or off at the same time, scattered all over different chromosomes and activator proteins bind to them to promote simultaneous transcription. (Eukaryotic version of operons)

RNA splicing

Method of Gene expression that removes introns from pre-mRNA and joins exons together, resulting in a mature mRNA molecule ready for translation.

mRNA degradation

Method of Gene expression that controls amount of mRNA transcript in a cell, controlling how much protein is produced from a specific gene.

miRNA

Small non-coding RNA molecules that regulate gene expression by binding to complementary sequences on target mRNA, leading to mRNA degradation or inhibition of translation.

siRNA

Small interfering RNA molecules that play a crucial role in the RNA interference (RNAi) pathway, targeting mRNA for degradation and thus silencing gene expression. the “death tag” on mRNA

ncRNA

Non-coding RNA molecules that play roles in regulating gene expression and maintaining chromatin structure of either loose or condensed chromosomes depending on the cell stage.

piRNA

Class of small ncRNA that specifically causes x chromosome inactivation in females, and reestablishes appropriate methylation patterns in genome during gamete formation.

proto-oncogens

code for proteins that stimulate normal cell growth and division, but when mutated they become cancerous

pseudogens/gene fragments

Former genes that accumulated many mutations and no longer function

transposons

molecules that move within a genome by means of a DNA intermediate. Can move by ‘cut and paste’ or ‘copy and paste’ method. Alter gene expression by inserting into random places in genome.

retrotransposons

Molecules that move by means of an RNA intermediate that a transcript of the DNA. Always leave a copy at the original site.

cell differentiation

The process by which cells become specialized in structure and function

Morphogenesis

Physical processes that give an organism its shape, development of the form of an organism and its structures

cytoplasmic determinants

How different parts of the egg cytoplasm disperses into different cells, causing nucleus differentiation.

induction

Process where cell surface receptors and other signaling pathway proteins convey signals to target cells for differentiation.

homeotic genes (HOX)

Master regulatory gene that controls placement and spatial organization of body parts in organism by controlling developmental fate of groups of cells.

organogenesis

The 3 embryonic germ layers start differentiating into specific cells

SRY gene

Everyone is born female, but the activation of this gene causes embryo to become male.

blastomeres, blastula, blastocoel

During cleavage stage, many small cells called __________ form a hollow ball called a ____ that surrounds a fluid filled cavity called the _____

ectoderm

Most external germ layer, develops into skin ,nervous system, and parts of neck

mesoderm

Middle germ layer, develops into muscle, blood, blood vessels, bones, and connective tissue

endoderm

Internal germ layer, develops digestive and respiratory tracts, and glands that feed them.

DNA technology

Techniques for sequencing and manipulation DNA, and analyzing gene expression

biotechnology

Manipulation of organisms or their components to make useful products

nucleic acid hybridization

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

Genetic engineering

Direct manipulation of genes for practical purposes

single nucleotide polymorphism

Single base-pair site where variation is found in at least 1% of the population

stem cell

relatively unspecialized cell that can reproduce indefinitely and differentiate into different specialized cells

totipotent

A cell with the potential to undo it’s differentiation and then give rise to all the specialized cell types in an organism.