ch 15 Flashcards
genome
full set of genes an organism contains, noncoding regions of the complete DNA sequence for a particular organism
synonymous substitution also known as
silent substitution, no change in amino acid
nonsynonymous substitution
missense mutation, change in amino acid
nonsense substitution
nucleotide substitution in a sequence that results in a stop codon, terminating protein produces new stop codon
neutral theory of molecular evol
most mutations dont affect amino acid being coded for, such mutations accumulate in a population at. rates driven genetic drift and mutation rates
positive selection
natural selection that acts to establish a trait that enhances survival in a population
gene duplication, potential outcomes?
a way that genomes can acquire new when a gene is duplicated, one copy of that gene is potentially freed from having to perform its original function
morphogens
diffusible substance whose concentration gradient determines a developmental pattern in animals and plants
hox genes and role in evolution
conserved homeotic genes found in vertebrates and other animal contain the homeobox and specify pattern and axis formation in these determine what organ will be made at given location
lateral gene transfer
horixontal movement of individual genes
rates of nonsynonymous subtitutions and synonymous are roughly the same. what can we infer
most of the amino acid substitutions at this gene are neutral syn=non
nonsynonymous mutation is also called
missesnse mutation
population= 6000. what is probability that a newly arisen mutation will become fixed in this population
1/12000; 1/2N
list events likely to occur after a gene duplication event
one pseudogene,
one new function
both share original function
but they can be expressed at diff time and tissues
sexual reproduction makes natural selection____ efficient by ____ the ____ of the number of deleterious mutations among individuals
more; increasing; variance
gene families are groups of____ genes that arose by ____ and ___
homologous; gene duplication; sequence evolution
when researchers apply principles of evolution to produce new molecules that can be used for pharmaceuticals, they are
performing in vitro evolution
A fruit fly is discovered with a wing growing out of its body where an eye normally grows. The rest of the fly’s body is normal. what could explain this phenomenon?
mutation ocurred in a hox gene that is responsible for directing organ formation in the head segment
how does modularity allow for rapid evolutionary change
a single change in the expression of a developmental gene in one module of a developing animal can lead to a large physical change in the animal’s morphology
