Evolution & Signal Trans (lect 1&2) Flashcards
Random processes
mutation & sex recombo
non-random processes
natural selection
T/F: Not all adaptations are optimally intelligent?
T: The human throat is an ex
T/F: Chimps are more related to gorillas than humans are
F: chimp and humans are more closely related than chimps and gorillas
What are phylogenetic trees based on
mito rRNA seq
what evidence supports the theory of evolution
fossil record, artificial selection, phylogenetic similarities
what is adaptive radiation and provide an example
opening of many new niches
bats learning how to fly enabled them to eat nectar, blood, or fruits, etc.
what are the 2 facts and conclusion that can be drawn from the theory of evolution
1- repro rates of all organisms are high; if mortality rates did not balance repro rates..populations would quickly rise
2- all organisms are variable and offspring are similar to parents due to heritable features
conclusion- diff among individuals influence how well those individuals survive and repro; traits that inc probability that their bearers will repro successfully will get passed on
why don’t “gaps” in the fossil record discredit the theory of evolution
gaps are time periods when rapid change occurred–> punctuated equilibrium
cetaceans had gaps, but fossils transitioning from land to see were found
types of phylogenetic similarities
morphology/anatomy, vestigial organs, comparative embryology, comparative biochem/genetics
what method of dating fossils is used and why
radiometric dating; radioactive decay is not influenced by temp, pressure or other env variables
analogous vs homologous limbs
analogous: no common ancestor, convergent evol, shaped by env, diff bones, same function
homologous; common ancestor, diff function same bones
explain “ontogeny recapitulates phylogeny”
the steps of an individual’s dev recreates the history of that specie’s evol
provide an ex of comparative embryology
we have gill slits and post-anal tail just like chickens do
what is used to date younger fossils?older?
carbon-14–> carbon-12;
potassium-40–> argon-40
what are the 3 stages of signaling
reception, transduction, response
what are the 2 main groups of receptors. what are the 3 subgroups of receptors?
Main: cytoplasmic, transmembrane
Sub: (transmembrane) G protein linked, enzyme linked, ion channel
what are some types of secondary messengers
cAMP, cGMP, Ca+2, DAG, IP3
what are the 3 parts to the cell theory
1) living organisms are composed of cells
2) cell is basic functional unit of life
3) all cells come from pre-existing cells
describe the 5 main types of signaling
1) gap junctions (direct)- small molecules can pass btwn cells that are connected by gap junctions w/o crossing the membrane. cytoplasm is continuous via pores formed by connexon
2) autocrine (indirect)- sending & receiving signals are the same..releases a factor that itself has a receptor for
3) paracrine (indirect)- receiving cells is near sender, ex. histamine, EGF
4) hormonal (indirect)- sim to paracrine but longer distance
5) synaptic (indirect)- electrical signals stimulate neurotransmitter release
how many transmembrane helices do GPCRs, G proteins, and RTKs have respectively
7, 3, 1
detail GPCR pathway
ligand binds to GPCR, GPCR undergoes conformational change, interacts w an inactive G protein bound to GDP. Interaction stimulates activation of G protein so drops off GDP, picks up GTP, and activates effector protein via alpha subunit