EVOLUTION

Question 1

define fossil

Answer 1

any preserved trace left by an organism that lived long ago

Question 2

define the 4 steps involved in fossil formation

Answer 2

1. Death and decay
2. Rapid burial
3. Permineralisation
4. Erosion and Exposure

Question 3

define 4 optimal conditions for fossil formation

Answer 3

1. Rapid Burial
2. Alkaline soil conditions
3. contains hard body parts - bone, teeth, shell
4. absence of decaying microorganisms

Question 4

define artefacts

Answer 4

objects made by humans
eg. stone tools, carvings, paintings

Question 5

what are 4 problems with the fossil record

Answer 5

1. fossils aren’t found yet
2. fossils cannot be dated
3. didn’t get fossilised
4. only some parts of organism was fossilised

Question 6

what are 2 dating techniques of fossils

Answer 6

absolute dating
relative dating

Question 7

define absolute dating

Answer 7

finding out the actual age of specimen in years

Question 8

define relative dating

Answer 8

comparing of fossils to tell us whether the specimen is older or younger than another fossil

Question 9

what is the half life for Potassium Argon Dating

Answer 9

1.25 billion years

Question 10

what occurs over time for potassium argon dating to be measured

Answer 10

potassium-40 levels decrease
argon-40 levels increase

Question 11

what is potassium argon dating used for

Answer 11

dating volcanic rocks, not fossils

Question 12

what age can potassium argon dating be used to date fossils

Answer 12

samples older than 100,000-200,000 years old

Question 13

what occurs overtime in carbon-14 dating

Answer 13

carbon-14 levels decrease, Nitrogen-14 increase

Question 14

what is the half life for carbon-14 dating

Answer 14

5730 years

Question 15

what is radiocarbon dating used to date

Answer 15

anything that used to be living (contained CO2)

Question 16

define stratigraphy

Answer 16

study of layers (strata)

Question 17

what are the two types of stratigraphy

Answer 17

principal of superposition
correlation of rock strata

Question 18

what does the principal of superposition assume

Answer 18

assumes that in layers of sedimentary rock, the layers at the top are younger than the layers beneath

Question 19

what is a limitation for the principal of superpostition

Answer 19

animals/humans sometimes bury artefacts /fossils - placing them deeper leading to an inaccurate assumption of their age

Question 20

what occurs in the correlation of rock strata

Answer 20

involving matching layers of rock of similar age from different areas

Question 21

define index fossils

Answer 21

living things that were present on earth for a short amount of time and are widely distributed on earth

Question 22

define evolution

Answer 22

the gradual change in characteristics of a species overtime

Question 23

define speciation

Answer 23

two populations because different enough through evolution that they can no longer interbreed to form new species

Question 24

define comparing dna

Answer 24

the sequences/order of nitrogenous bases in a dna sequence are analysed for similarities

Question 25

what occurs in comparative genomics

Answer 25

the complete set of dna in a cell of an organism is analysed

Question 26

what are endogenous retroviruses

Answer 26

stretches of non-functioning dna sequences of dna that have become part of an organisms genome when an ancient virus inserted its genetic material into a cell

Question 27

why do we compare mitochondria in comparative studies

Answer 27

mtDNA is inherited from an individuals mother allowing to trace back to maternal common ancestor

Question 28

what can be analysed in protein sequence comparing

Answer 28

sequences in which proteins are joined compare type and sequence of amino acids in similar proteins

Question 29

what are proteins found in all species called give an example

Answer 29

ubiquitous proteins cytochrome C - cellular respiration

Question 30

define bioinformatics

Answer 30

used to align the sequences and find similarities and differences in dna sequences through computer analysis

Question 31

define the importance of comparative embryology

Answer 31

comparing the early stages of development in organisms strong similarities in embryos at different times for different species evolving from a common ancestor

Question 32

define what homologous structures

Answer 32

similar structures in anatomy that are inherited by common ancestors ex. pentacle limb structure

Question 33

define what is meant by vestigial structures

Answer 33

structures of reduced size that don’t have a function remains of organs that once functioned in ancestral forms but overtime, due to changing environments and living conditions, their function became non-essential