2.5 The Origin and Development of Life on Earth

Question 1

What is the study of fossils known as?

Answer 1

Palaeontology

Question 2

What are fossils?

Answer 2

The preserved remains of living things

Question 3

What are 5 types of fossil you need to be able to identify?

Answer 3

• ammonites
• corals
• plants
• trace fossils
• trilobites

Question 4

What are the parts of trilobites?

Answer 4

• cephalon (head)
• thorax (body)
• pygidium (tail)

Question 5

What is a fossil track?

Answer 5

A trail on the seabed where a marine creature (e.g. ammonite) has been rolled along

Question 6

What environment were trilobites formed?

Answer 6

Marine

Question 7

What environment were corals formed?

Answer 7

Shallow marine

Question 8

What environment were ammonites formed?

Answer 8

Warm shallow marine

Question 9

What environment were plant fossils formed?

Answer 9

Cold forests (mangrove swamp-like conditions)

Question 10

What is the main theory about how living things developed?

Answer 10

Living things developed from molecules that replicate themselves

Question 11

What are the two possible origins for molecules that replicate themselves?

Answer 11

• they were produced by the conditions on earth at the time

* they came from somewhere else, such as another planet

Question 12

What is deoxyribonucleic acid (DNA)?

Answer 12

A molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses

Question 13

What is ribonucleic acid (RNA)?

Answer 13

A molecule that is involved in coding and expression of genes

Question 14

What is one of the best examples of exceptional preservation?

Answer 14

The Burgess Shale fauna

Question 15

Where did life probably originate from?

Answer 15

The oceans or hydrothermal pools

Question 16

How long ago did life probably originate?

Answer 16

3500 Ma

Question 17

How can the diversity in the evolution of life be identified?

Answer 17

From the fossil record

Question 18

How was Burgess Shale formed?

Answer 18

Mudstones and shales laid down on floor of shallow sea

Question 19

How is the Burgess Shale different?

Answer 19

Some soft bodies were also preserved as fossils

Question 20

How were some soft bodies preserved in the Burgess Shale?

Answer 20

Conditions for fossilisation were perfect - shallow sea

Question 21

What did the development of predators in the Cambrian era cause?

Answer 21

The rapid evolution of defensive features e.g. armour, mineralised bodies and shells

Question 22

What group did over half of the fossils in the Burgess Shale come from?

Answer 22

Arthropods

Question 23

What were the most abundant arthropods?

Answer 23

Trilobites

Question 24

What animal in a fossil shows the evolutionary links between different groups of animals or plants?

Answer 24

Archaeopteryx

Question 25

How was the rock that archaeopteryx fossils are found in formed?

Answer 25

* limestone forming in marine conditions, with fossil sponges and animals creating reefs * shallow water behind formed lagoon and water evaporated, and CaCO3 precipitated out as limy mud * limestone separates into thin plates (used as building stone)

Question 26

What species does the archaeopteryx link?

Answer 26

Reptiles and birds

Question 27

How does the archaeopteryx link reptiles and birds?

Answer 27

It has wings with feathers, but a reptilian head with no obvious beak

Question 28

What are the fossils of our closest biological relatives?

Answer 28

Hominids

Question 29

How long ago was the hominid 'Lucy' estimated to lived?

Answer 29

3.2 million years ago

Question 30

What is an Auatralopithecus afarensis?

Answer 30

A human-like creature

Question 31

Which part of the body provides some of the best evidence for bipedal movement?

Answer 31

The femur (or thigh bone)

Question 32

What is biostratigraphy?

Answer 32

The branch of dating rocks that assigns relative ages of rock units by using the fossils contained within them

Question 33

What is correlation in biostratigraphy?

Answer 33

Demonstrating that a particular bed in one geological section represents the same period of time as another bed at some other section

Question 34

Why are fossils useful when dating rocks?

Answer 34

Sediments the same age can look completely different due to local variations in the sedimentary environment

Question 35

What does the oil industry use biostratigraphy for?

Answer 35

To correlate reservoir and cap rocks

Question 36

What are Forams?

Answer 36

A type of microfossil

Question 37

Where are Foraminifera found?

Answer 37

In all marine environment

Question 38

What does it mean if a creature is planktonic?

Answer 38

They float around in the seawater

Question 39

What does it mean if a creature is benthonic?

Answer 39

They live on the seabed

Question 40

Is the fossil record complete?

Answer 40

No