AP Bio Unit 1

Big Bang

14 bya

Earth formed

4.6 bya

Core principles of Darwin’s theory of evolution

natural selction, variation -> competition -> advantageous reproduce -> increased in freq

Lamarack’s theory of evolution

use or disuse + aquire traits could be inherited

Artificial selection

humans select for desired traits

Sexual selection

female prefers certain traits in mate

directional selection

one phenotype clearly + consistently advantageous

diversifying/disruptive selection

multiple phenotypes successful, and several emerge as organisms avoid comp

stabilizing selection

clear optimal level of behavior. reduces diversity but increases efficiency + survival

Genetic dimorphism

different phenotype for each gender

Conditions on Early earth and its effect on life

reducing (add electrons) atmosphere w CO2, methane, ammonia, water, n2, and h2. no free o2 or o3 -> no oxidization (longevity of complex biomolecules), longevity of chemical reaction products lots of mutations (increase diversity). lots of E -> UV radiation (no ozone layer), frequent severe thunderstorms, geothermal activity, ionizing radiation. lots of chemical reactions that could never occur now.

Miller/Urey experiment

proved that biomolecules (simple sugars, AAs, fatty acids, nucleotide precursors) can spontaneously form from early earth's atmospheric conditions

How were the first cells emerged?

probionts were cell precursors aka molecules in a membrane, containing biomolecules (simple sugars, AAs, lipids, RNA (self replicating, store info, acting like enzyme by driving earliest metabolic reactions). membranes allowed for self containment so higher concentration of molecules so higher rxn rate

How did protocells inherit or divide?

fission, no inheritance capabilities

Benefits of diploid

cover a "bad" gene, more diversity, make haploid gametes (sexual reproduction)

Aerobic metabolism

using oxygen to convert food into energy

Endosymbiont theory

prokaryote grew (infoldings in membrane) and engulfed aerobic eubacteria (mitochondria) + cyanobacteria (chloroplast). M + C reproduce independently, have their own DNA, and a double membrane

Eukaryotes

compartmentalization, infolding of membranes, organelles that allow for more complex metabolism. protists were the first eukaryotes (very diverse)

Multicellularity usefulness

differentiation/specialization (diversity), larger size (less predators + more food access), replace damaged cells

Cambrian explosion

rapid burst of evolution, high mutation rate + slow development of protective ozone layer. true multicellularity + differentiation after the explosion

3 domains

bacteria, archaea + eukaryota (more closer)

Significance of land masses moving

organisms isolated from one another, fueling diversity through natural selection

Index fossils

assign a date to newly found fossils under the same rock strata, geological distribution helps figure how out land masses moved/where the organism lived

Radiometric dating and half life

*** and the time it takes for half of the material to decay

Comparative embryonic development

embryos of related organisms have similarities in the early stages of development

Why not perfection in natural selection?

fittest traits, but not the best. random allele variety and enviornmental changes

Micro vs macro evolution

small changes over time vs large scale changes seen over thousands/millions of years (speciation or extinction)

Causes of microevolution

genetic drift, nonrandom mating, natural selection, gene flow, mutation

Genetic drift

random events that change allele freqs

Bottleneck effect vs founder effect

bottleneck: catastrophy reduces population, founder effect: small handful of og population begin a new population

Gene flow

immigration/emigration change population size, which change allele freqs

Divergent evolution

evidence: homologous structure, organisms branch out from CA

Convergent evolution

evidence: analogous structure, organisms face extreme envionrment/task and few structures can accomplish the task

Co-evolution

evolution of one species influences the other, like predator prey relationships

Evidence for different kinds of evolution

biogeography (geological strata + locations of fossils to observe differences over periods of time), fossil evidence

homologous structure

similar body sstructure + CA, but possibly different function

vestigial structures

no longer used in an organism, but may be used in related organisms or in the past

Adaptive radiation

rapid diversification from CA into diverse new habitats with different selection pressures

Null hypothesis

default, assume no relationship

chi square test

compare expected from observe values vs observed values

How to perform chi square test

(o-e)^2/e for every set of observed/expected value. DF is # of groups -1, and compare to CV at p

H-W conditions

large population, random mating, no mutation, no immigration/emmigration, no natural selection

Using H-W and chi square test together

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Adaptations in early organisms that supported life on land

improved support (wood/skeletons), water transport in plants (roots, stems, vascular tissues), transport (limbs/muscles), water retention mechanisms (waxy cuticle/advanced excretory systems), UV protection, reproduction w/o water

Homology vs analogy (in bio)

homology is similar structure, genetics, biochem but diff fxn; analogy is similar fxn but diff structure, genetics, biochem

phylogeny logic

similar DNA -> similar traits -> CA, as DNA governs physical and biochemical traits

Law of parsimony

simplest and most likely explanation is correct for phylogeny/cladograms

Allopatric speciation

speciation in different places. geographical separation most common w physical and reproductive isolation. locations have difff selection pressures and gene pools don't mix.

Sympatric speciation

speciation in same place

reproductive isolation (pre-zygotic)

geographical, ecological (diff habitats in same area), temporal (mate during diff times), behavioral (diff mating rituals), mechanical, gametic (sperm and egg don't fuse)

reproductive isolation (post-zygotic)

hybrid infertility (embryo doesn't develop properly), hybrid inviability (doesn't survive into adult)

Autopolyploidy vs allopolyploid

auto is that meiosis error leads to self fertilization (single species), allo is hybrid (changed) gamete merges with one of the parent gametes

Definition of species

group of organisms that can breed + produce viable, fertile offspring

Gradualism vs punctuated equilibrium

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Effect of sexual selection on reproductive isolation

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Why don’t all disadvantageous traits disappear over time?

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How can new alleles be introduced?

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