transcription

regulatory proteins that bind to the start  of genes,  either promoting or inhibiting the transcription of the gene

-example of transcription factor
-blocks tryptophan synthesis

2 classes of genes that can have an effect on how other genes function

alter how certain other genes are expressed in the phenotype

can either initiate or block the expresion of other genes

regulator genes that are involved in subdividing an embryo into what will become the major body parts of an individual

homeotic genes aka

defined by dna sequence of 180 nucleotides that code for a protein domain

homeobox code for a protein domain called

their effect does not normally occur unless certain environment factors are present

although genes contain all the information an organism uses to function,the environment plays an important role in determining the ultimate phenotype --- a dichtomy often  referred to as

during the process of DNA replication, errors occassionally occur in the polymerization of the second strand.  these errors are called

(mutations) error rates are usually very low ____ - error in every 10-100 million bases due to _____________ ability of DNA polymerase

processes that increases the rate of changes in DNA  are called

errors that create large structural changes in DNA sequence --  duplications, inversions, or deletions of entire regions, or ther accidental exchanging of whole parts between different chromosomes

chromosomal crossover aka

the exchange of genetic material between homologous chromosomes during prophase 1 of meiosis

the contact bet. two chromatids that will soon undergo crossing over is known as

illustrated the crossing over (year 1916)

______________ produce organisms with different genotypes, and those differences can result in different ___________

transmission of traits

genes that have more than two alleles

two alleles can be codominat

apparent blending can occur in the phenotype when there is incompatible dominance resulting in an ___________ of a trait in heterozygous individuals

term applied when one gene interferes with the expression of another (eg: baldness/widow's peak)

a pattern responsible for many features that seem simple on the surface

polygenic inheritance is distinguished by

an effect of a single gene on more than one characteristic

eg: of pleiotropy