molecular basis of evolution Flashcards
evolution explains both the ___ and ____ of species
unity and diversity
what is evolution
process of gradual change during which new species arise from older species
what are mutations
generations of new genetic material by mistakes in copying of DNA strand
what is taxonomy
describing, identifying, classifying and naming of organisms
genus
group (clade) of closely related species
what is the hierarchy of categories (taxa)
domain, kingdom, phylum, class, order, family, genus, species
what are species
a group of organisms capable of interbreeding and producing fertile offspring, or a group of organisms w similar morphology or genetic identity
what are some ways we identify species
morphology, ecology, geographic distribution, biochemistry/ physiology, nucleic acid sequence
what is the dichotomous key
tool for classification that divides groups into two
ex w a bunch of animals splitting into groups w 4 legs and groups 4 8 legs
then splitting those groups into further groups with wings and no wings etc etc
works but ignore true relationship of organisms
what must taxonomic tools consider
ancestral lineages and origins
homologous structures
share a common origin
ex human, whale and bat fingers
analogous structutures
share a common function but arose from different ancestors ex bat and bird wing
what is phylogeny
study of evolutionary history of species, helps us view relationships
terminal taxa
things at the end of the tree (the descendants), can be living or fossils
give an example of why phylogeny is important
use of drugs, same drugs for different parasites with recent common ancestor
how is dna organized in eukaryotes
in nucleus where dna is wrapped tightly in chromosomes, also in mitochondria/ chloroplasts
what do genes do
code for info to build proteins to replicate/ reproduce, produce energy and form structure and perform function
what is common descent
concept where one species is the ancestor of 2 or more species later in time
what is the genome
total of all hereditary info in a cell
what are chromosomes made up of
genes; lengths of DNA coding for functional protein
what happens to genes
transcribed to mRNA and translated into proteins
phenotype
observable characteristics based on gene expression
name types of mutations
defective chromosomes through rearrangement, recombination or insertion/deletion
point mutations by nucleotide base substitutions/ insertion or deletion
endogenous cause of mutation
spontaneous due to normal cellular division
exogenous mutation
caused by chemical, radiation, transposable elements and viruses
when are mutations heritable
if they occur in germinal tissue
when are mutations not heritable
if they occur in somatic tissues
if a mutation leads to no change on the protein function its called
synonymous mutation
what are 3 ways a mutation could result in
no change on protein function
change in protein function (new phenotype)
loss of protein function (new phenotype or disease)
genetic diversity reflects ___ of populations, why?
health
gives populations ability to respond to different environments and adapt to changing conditions, natural selection
natural selection
mechanism of evolution
organisms more adapted to their environment more likely to survive and pass on the genes
factors that affect genetic diversity
-mutations
-natural selection
-migration
-random genetic drift: bottlenecks and founder effects
bottlenecks
predation or catastrophic event
founder effects
new small population arising
for animals family name ends in
“idae”
