Exam 2

Question 1

uniformitarianism

Answer 1

idea that the “present is the ket to the past” present rates of change are usually extremely slow and gradual

Question 2

catastrophism

Answer 2

view that earth history was punctured by events of tremendous violence and size that could form/reshape rock units on a global scale quickly

Question 3

relative dating

Answer 3

placing events, rock units, and/or organism’s range in a chronological sequence

Question 4

absolute dating

Answer 4

estimating an age for an event, rock unit, and/or organisms range in years

Question 5

calculating absolute ages

Answer 5

count annual features- annual tree rings, annual layers in glacial ice, varies: annual layers in lacustrine deposit

Question 6

how to calculate absolute ages

Answer 6

time=total/rate

Question 7

sediment thickness

Answer 7

know total thickness accurately, know average rate accurately (assumptions very hard to test :()

Question 8

William Thomson, Lord Kelvin

Answer 8

the earth must have been unfit fro the habitation of man as at present constituted, unless operations have been performed =, which are impossible under the laws at which the known operations going on at present in the material world are subject

Question 9

element

Answer 9

most fundamental substances into which matter can be separated by chemical means

Question 10

atom

Answer 10

smallest individual particle that retains all the chemical properties of a given element

Question 11

proton

Answer 11

positively charged particle

Question 12

neutron

Answer 12

electrically neutral and approximately the sea mass as the proton

Question 13

electron

Answer 13

small negatively charged particle, mass of the electron is 1/1850th of the proton

Question 14

isotope

Answer 14

atoms of the same element but with different numbers of neutrons, the rate of decay is constant fro any radioactive isotope and expressed as half life

Question 15

half life

Answer 15

time it takes for half a radioactive isotope to decay

Question 16

radiometric dating

Answer 16

number of half lives x half life = age
the percentage of radioactive atoms that decay during one half-life is always the same (50%)

Question 17

radiometric dates

Answer 17

calibrate the sequence

Question 18

geologic time scale

Answer 18

built and refined over centuries using tools described

Question 19

aside

Answer 19

old ages made uniformitarianism, the guiding principle for interpreting earth history for more than 100 years

Question 20

cambrian explosion

Answer 20

geologically sudden appearance of macroscopic life -540-510 Ma

Question 21

pikaia

Answer 21

a 500 minion year old chordate from the Burgess Shale fossil deposits

Question 22

cephalochordates survive today

Answer 22

anterior mouth, pharynx, complete digestive system, gills slits to outside
sensory organs concentrated in head region
well defined dorsal notochord and dorsal nerve cord
muscles in V-shaped bundles, post-anal tail (with notochord)
NO JAWS NO BONE

Question 23

Phylum chordata

Answer 23

head-region with sensory organs
mouth that opens into muscular pharynx with gill slits
stiff but flexible dorsal notochord
dorsal nerve cord
complete digestive system
post-anal tail including notochord
V-shaped muscles bundles (myomeres

Question 24

Jawless fishes (agnathids)

Answer 24

2 modern taxa, relatively common and diverse 490-420 Ma extinct forms as generally referred to as OSTRACODERMS

Question 25

cladogram

Answer 25

branching diagram that group organisms based on presence of shared derived characters

Question 26

why climb out on land

Answer 26

1. avoid predators 2. get from one drying puddle to another 3. access to terrestrial food sources

Question 27

tetrapods

Answer 27

amphibians to amniote changes challenges- respiration, limbs and locomotion, desiccation, reproduction solutions- lungs, skeletal changes, keratinized skin, amniotic egg

Question 28

amniote groups

Answer 28

anapsids, synapsids, and diapsids- subgroups of the amniotes, distinguished by cranial fenestra archosaurs- a subgroup of daisies that includes dinosaurs

Question 29

ichthyostega

Answer 29

an early tetrapod that lived around 370 million years ago in greenland

Question 30

eveolution of the skeletal

Answer 30

fish -> amphibian -> reptile skeletal more integrated joints better defined weight/stress can be carried by bones

Question 31

amniotes

Answer 31

can be divides into three major groups recognized by the number and position of holes in the skull

Question 32

archosaurs

Answer 32

diapsids with additional pre-orbital fenestra, also teeth set in sockets and different ankle structure than other diapsids

Question 33

archosaur cladogram

Answer 33

depicting the same information with some nodes labeled (dino24-13)

Question 34

cladograms

Answer 34

group organisms based on how closely related they are to each other

Question 35

triassic global climate

Answer 35

1. arid 2. hot (warm at poles)

Question 36

jurassic climate

Answer 36

1. arid 2. warm

Question 37

cretaceous climates

Answer 37

1. relatively wet 2. hot

Question 38

synapsids

Answer 38

were dominate tetrapods during the permian but anapsid and diapsids also lived then

Question 39

proposed change

Answer 39

ornithischians and theropods are more closely related to each other than either is to the sautopodomorphs

Question 40

why?

Answer 40

re-examination of existing fossils with more characters evaluated. new specimens seem to support the revised view, but not everyone agrees

Question 41

orientation

Answer 41

anterior/posterior dorsal/ventral medial/lateral proximal/distal

Question 42

vertebral column- regions

Answer 42

cervical dorsal sacral caudal