BIOEE 1780: PRELIM 1

Question 1

\FOSSILS

Answer 1

are the remains or traces of once living organisms and they can take many forms: skeleton, impression cast trace or even poop

Question 2

Why aren’t there more fossils

Answer 2

predators and scavengers
bacterial decay
dissolution in water
physical disturbance (wave action, wind etc)

Question 3

Special conditions to promote fossilization

Answer 3

rapid burial
protection from physical disturbance
anaerobic environments

Question 4

Where are most fossils found in

Answer 4

Sedimentary Rocks

Question 5

Sedimentary Rocks

Answer 5

are formed from deposition of sediments falling to the bottom of a body of water

Question 6

What gets preserved from fossils

Answer 6

• the hard parts in ANIMALS
• seeds, pollen leaves, wood, and rarely flowers in PLANTS
• bacteria, microbial mats in MICROBES

Question 7

Stromatolites

Answer 7

formed from biofilms of cyanobacteria that trap sediment which eventually hardens and forms layer

Question 8

Types of preservation

Answer 8

• original remains
  -permineralization retains structures
  -trace fossils
  -impression fossils

Question 9

Impression fossil

Answer 9

are fossils made from a carbonaceous film imprint of the organism

Question 10

Permineralization

Answer 10

is a process where minerals are deposited in tiny holes within bones, or wood and over time completely replace organisms and all that remains is a stone structure

Question 11

original remains

Answer 11

have the most information

Question 12

Lagerstatten

Answer 12

storage place and is used to refer to exceptional perservation

Question 13

Cambrian Explosion

Answer 13

period of time at the beginning of the Phanerzotic is when nearly all of the major animal phyla appeared

Question 14

Burgess Shale

Answer 14

famous lagerstatten from the cambrian and has yielded many of the organisms that contribute to our understanding of the Cambrian explosion

Question 15

Relative Dating 4 principles

Answer 15

-superposition
-original horizontality
-lateral continuity
-cross-cutting

Question 16

superposition

Answer 16

youngest layer on top

Question 17

original horizontality

Answer 17

layers are first deposited horizontally and due to the movement of continental plates are repositioned

Question 18

lateral continuity

Answer 18

each layer is deposited at the same time and so seven if erosion has removed has removed some of the layer- that layer is still the same after the gap caused by erosion

Question 19

cross-cutting

Answer 19

geological layers or intrusions that cut across other layers are always younger

Question 20

Index Fossils

Answer 20

are fossils that are distinct to a particular rock layer and are also geographically widespread to help identify layers in different locations

Question 21

How do we know the age of a fossil

Answer 21

• relative dates
• absolute dates

Question 22

geological chronology

Answer 22

is the science of dating geological layers and fossils

Question 23

absolute dating

Answer 23

based on the radioactive decay of unstable isotopes
- decay of parent isotope gives rise to stable daughter isotope and the rate is referred to as half-life
-ONLY USES IGNEOUS ROCK because of 100% parent isotope

Question 24

3 types of isotopes

Answer 24

• uranium- lead (older fossils)
• potassium- argon (older fossils)
• carbon (recent fossils)

Question 25

Relative dating

Answer 25

layer a is older than layer b, does not give an exact time of the fossils

Question 26

Branch

Answer 26

is a lineage evolving through the time that connects successive speciation of other branching events

Question 27

phylogeny

Answer 27

depicting the evolution of a lineage into branches

Question 28

tips

Answer 28

the terminal end of an evolutionary tree, representing pieces,molecules of population being compared

Question 29

internal nodes

Answer 29

a node that occurs within a phylogeny and represents an ancestral population or species

Question 30

node

Answer 30

is a point in phylogeny where a lineage splits

Question 31

clade

Answer 31

a node and all its descendants

Question 32

taxa

Answer 32

group of organisms that a taxonomist judges to be cohesive taxonomic unit such as a species or order

Question 33

monophyletic

Answer 33

a group of organisms that for a clade

Question 34

paraphyletic

Answer 34

a group of organisms that share a common ancestor, although the group doesn't include all the descendants

Question 35

characteristics

Answer 35

a heritable aspect of organisms that can be compared across taxa

Question 36

synapomorphy

Answer 36

derived form of a trait that evolved in the immediate common ancestor of the group & was inherited by all of its descendants

Question 37

outgroup

Answer 37

a group of organisms that is outside of the monophyletic group being considered, can be used to infer the ancestral states of character

Question 38

homoplasy

Answer 38

describes a character state similarity, not due to shared descent

Question 39

convergent evolution

Answer 39

independent origin of similar traits in separate evolutionary lineages

Question 40

Evolutionary reversal

Answer 40

describes the reversion of a derived character a form resembling its ancestral state

Question 41

parsimony

Answer 41

a principle that guides the selection of the most compelling hypothesis among several choices

Question 42

vestigial

Answer 42

Structures that have no apparent function and appear to be residual parts from a past ancestor

Question 43

homology

Answer 43

when characteristics are due t common ancestry

Question 44

All life shares

Answer 44

amino acids, DNA/RNA, shared biochemical pathways, and membrane-bound cellular organization