Bio Final

4.6 BYA

4.6 BYA

the earth is estimated to be about _____________________

oxygen

Early Earth atmosphere lacks _________

eukaryotics

the endosymbiont theory describes origins of ________

paleozoic era

-between 540-250 million years ago
-encompasses major periods of biological diversification

cambrian period

- 543-490 million years ago
-this is when all major animal phyla evolve

silurian period

-about 443-417 million years ago
-is when first vascular plants appeared
-first animals moved onto land
-the arrival of jawed fishes
(in paleozoic era)

devonian period

- 417-354 million years ago
-LOTS of fishes
-the first amphibians appear
-mysterious extinction
(in paleozoic era)

mesozoic era

- 250-65 million years ago
-the age of reptiles

cenozoic era

- 65 million years ago-present
-the age of mammals

fossils

oldest evidence on evolution

-compression fossils
-plants

_________________ form when fine sediment compresses a specimen
found in sedimentary rock (e.g. sandstone, limestone, shale, etc.)
best for _____________

petrification fossils

_____________________ form when an organism is buried and dissolved minerals replace bone or other organic material
can make for highly detailed fossils

-impression fossils
-trace fossils

__________________ form when an organism makes an impression in the mud
can form _________________ which can provide insight into animal behavior

-cast fossils
-devil's corkscrews

_________________ form when impressions are filled with mud, providing a mold

________________ are fossilized burrows left by extinct beavers

paleocaster

-intact preservation fossils
-inclusions

__________________ happen when tree resin traps an organism and hardens (called amber)
bodies lodged in amber are called _______________
preserve amazing detail

homologous structures

indicate shared/common ancestry

analogous structures

structures which have similar function but different ancestral origins

uniformitarianism

james Hutton proposed the theory of ____________________ which suggests the slow processes acting today also occurred in the past

catastrophism

__________________ states that violent events are responsible for the geologic formations of today

population

evolution occurs at the ____________ level

microevolution

measured via allele frequencies

natural selection

darwin termed the preservation of favorable traits over inferior ones as _____________________

genetic drift/small populations

_________________ is a change in allele frequencies that happens purely by chance
most likely to impact __________________

genetic bottlenecks

___________________ occur when there is a loss of alleles following a major drop in population

founder affect

a loss in alleles can result from the _____________________ which occurs when a small population becomes isolated

directional selection

in ____________________ one extreme phenotype is fittest and the environment selects against other variations

disruptive selection

___________________ occurs when two or more extreme phenotypes are selected

stabilizing selection

__________________ occurs when extreme variations are selected against, and intermediates are favored

balanced polymorphism

for some genes, multiple alleles can be maintained in a _____________________________

phenotype

for selection to act on a particular allele, it must be expressed; ________________ is the physical manifestation of an organisms genetic make up

biological species concept

______________________ defines a species as a population or group of populations whose members can interbreed and produce fertile offspring

speciation

under the biological species concept, __________________ occurs when members of a population can no longer interbreed

prezygotic

_______________________ barriers occur before the formation of the zygote or fertilized egg

postzygotic

______________________ barriers occur after the formation of the zygote and reduce the fitness of a hybrid offspring

-allopatric
-vicariance

_________________ speciation occurs when a physical barrier separates a population into two or more groups
the formation of these barriers is known as ____________________

parapatric

_______________ speciation occurs when members of a population enter a new habitat bordering the range of the parent population

sympatric

______________ speciation occurs when populations diverge while living in the same physical area

attachment stage

-the virus attaches to a receptor molecule on the host cell's surface

penetration stage

-stage when virus enters cell

-virus may be brought in by endocytosis

synthesis stage

-most important

-host cell produces copies of the viral genome

-this is the stage when mutations necessary for viral infection occur

assembly stage

step during which viral genome is packaged into capsids

release stage

-step when viruses leave host cell

-in some cases, viruses may bud out of host membranes, forming viral envelope

domains of prokaryotes

-archaea and bacteria

-prokaryotes were split into two domains based on the work of carl woese

differences in archaea vs. bacteria

-differences in cell wall structure

-differences in membrane structure

peptidoglycan

cell walls are made up of

gram (+) bacteria

have a thick peptidoglycan layer and so stain a dark, purple color

gram (-) bacteria

have an inner and outer membrane, with a thin peptidoglycan layer in between, so stain a light pink color

coccus

spherical bacteria

bacillus

rod shaped bacteria

spirillia

have a spiral or "cork-screw" shape

staphylococcus

grape like clusters of coccus bacteria

streptococcus

chains of coccus bacteria

protista

a eukaryote which does not fall into the kingdom plantae, animalia, or fungi

amoeboids

-shapeless protozoans

-move via the use of pseudopodia (pseudo=false, podia=feet)

-feed by phagocytosis

ciliates

-characterized by their abundant, hair-like cilia

-have complex organelles and structures such as contractile vacuoles and pores for waste removal

-many have a micronucleus which is passed on during conjugation

flagellate

whip-like extensions that allow for movement toward or away from stimuli (allow for motility)

bryophytes

seedless plants that do not have vascular tissue; rely on passive diffusion of nutrients and gasses

seedless vascular plants

have a xylem and phloem but do not produce seeds

gymnosperms

first seed plants (evolved during early permian period); meaning "naked seed"

angiosperms

flowering plants

xylem

transports water and dissolved minerals from the roots to all parts of the plant and is composed of two cell types

phloem

conducts dissolved organic compounds, primarily sugars

Nematoda

Phylum that roundworms become to

cohesion tension theory

plants move through water via

pressure flow theory

plants move sugar via

Chordata Phylum

Phylum including organisms with backbones

Cnidaria phylum

Have true tissues, derived from two germ layers, the endoderm, and ectoderm and belong to the eumetazoan

-jellyfish

Arthropoda Phylum

-Most species-rich phylum

-Most reproduce sexually and a vast majority lay eggs

Platyhelminthes

Phylum containing flatworms

Mollusca phylum

Phylum including organisms like clams, oysters, snails, and octopuses

-Characterized by a shell made of conchiolin

Annelida phylum

Segmented worms belong to this phylum

-Characterized by well defined segments and a well developed coelom

Porifera

Phylum that sponges belong to

contains around 5,000 species