changes in biodiversity over time

Question 1

steps in fossilisation

Answer 1

organism dies and is rapidly buried in sediment
oxygen poor and alkaline conditions contribute
either minerals in surrounding rock enter the hard tissues, forming mineralised fossils, or organism decays, leaving a mould in the rock.

Question 2

when did life first form

Answer 2

around 3.7 billion years ago

Question 3

what eon did prokaryotes arise

Answer 3

archean

Question 4

when was the great oxygenation event and what happened

Answer 4

2.4 billion years ago (beggining of the proterozoic eon), occurred when bacteria in the oceans evolved the ability to photosynthesise, and oxygen began accumulating in the atmosphere, killing off obligate anaerobes

Question 5

what are obligate anaerobes

Answer 5

microorganisms that are killed by normal atmospheric concentrations of oxygen

Question 6

when did eukaryotic and multicellular organisms arise

Answer 6

Proterozoic eon

Question 7

when did animals become terrestrial

Answer 7

around 400 mya

Question 8

what was the period called where organisms rapidly began to diversify

Answer 8

the Cambrian explosion

Question 9

examples of organism from the Cambrian explosion

Answer 9

trilobites and brachiopods

Question 10

two types of dating

Answer 10

relative and absolute

Question 11

what is the principle of superposition

Answer 11

rocks at the top layers are younger, while deeper rock are older (used for relative dating)

Question 12

what is an index fossil

Answer 12

fossils used to define and identify geologic period

Question 13

requirements for an index fossil

Answer 13

must be widely distributed, abundant, distinctive, and must have existed for a short and know period of time

Question 14

methods of absolute dating

Answer 14

radiometric dating (carbon 14 - nitrogen 14, and potassium 40 - argon 40) and electron spin resonance

Question 15

paleontology is the study of

Answer 15

ancient life represented by fossils

Question 16

define fossil

Answer 16

the preserved remains, impressions or traces of a once living organism

Question 17

types of fossils

Answer 17

mineralised, impression/trace, mould, cast and biosignature

Question 18

what is a mineralised fossil

Answer 18

when minerals from rocks surrounding fossil replace the organic material of the fossil over time

Question 19

what is an impression fossil

Answer 19

when a structure leaves an imprint in soft earth, which hardens and forms a fossil in the shape of the original object

Question 20

what are mould/cast fossils

Answer 20

mould is when the fossil decays and leaves an impression in its shape, while a cast fossil is when something fills this mould to form the shape of the organism

Question 21

what is a biosignature

Answer 21

chemical signs preserved in rocks that are inferred to be cellular (or the the product of metabolic activities)

Question 22

what is biogeography

Answer 22

study of the distribution of organisms, can be used to find patterns

Question 23

what is structural morphology

Answer 23

the study of the body structures and features in organisms

Question 24

homologous features

Answer 24

features between organisms that have different functions but similar structure

Question 25

analogous feature

Answer 25

have similar functions but different structures (such as wings)

Question 26

developmental biology

Answer 26

studies how an organism grows and develops

Question 27

convergent evolution

Answer 27

when similar features evolve independently in unrelated organisms

Question 28

divergent evolution

Answer 28

when 2 related organisms become more different over time

Question 29

adaptive radiation

Answer 29

divergent evolution of a large number of species within a relatively short period of time, from a common ancestor

Question 30

coevolution

Answer 30

when 2 species evolve together in response to selection pressures (such as flowers and bees)

Question 31

background extinction

Answer 31

the average rate of natural loss of species

Question 32

mass extinction

Answer 32

large scale extinctions following a disruptive change to global climate

Question 33

angiosperms are:

Answer 33

flowering plants

Question 34

what is the term used to describe the first terrestrial animals and all of their descendants

Answer 34

tetrapods

Question 35

vestigial structure

Answer 35

homologous structures that were once used in ancestral species, but due to disuse evolve to become smaller and weaker over time

Question 36

how far back can carbon dating be used

Answer 36

50000 years

Question 37

which is the correct order: 1. angiosperms formed 2. terrestrial life formed 3. first multicellular organism 4. mammals formed

Answer 37

3,2,4,1