Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Living Earth Quizzes > Long Answer > Flashcards

Long Answer Flashcards

1
Q

Describe how elements heavier than iron are formed, and the type of event that is responsible.

A

Supernova explosions of dying stars.
When the star has “burned” everything but iron, it has used up all its fuel.
The heat and radiation that have streamed outward preventing collapse under force of immense gravity, stop flowing.
Causing collapse = SUPERNOVA.
The forces of the explosion drive iron nuclei into each other, supplying the energy needed to force the iron nuclei to fuse into heavier elements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are carbonaceous chondrites, where are they found, and why are they important?

A

Non-volatile material of the solar nebula meteorites.

Formed in oxygen-rich regions of the early solar system.

Most of the metal is not found in its free form but as silicates, oxides, or sulfides.

They contain water-bearing minerals which is evidence of water moving slowly through their interiors not long after formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can we account for the compositional differences between the Earth and the Moon?

A

The Moon is thought to have formed from the debris of a small planet of different composition that collided with the Earth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the potential importance of clay minerals in the early evolution of life.

A

Clay minerals played a key role in chemical evolution and the origins of life, because of their ability to take up, protect (against ultraviolet radiation), concentrate, and catalyze the polymerization of, organic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why has the identification of the oldest fossils preserved in the geological record proved to be so problematic?

A

Very old and metamorphosed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How did the earliest Banded Iron Formations form, and how did the deposition of the later Banded Iron Formations differ?

A

Anoxygenic photosynthetic Fe2+ oxidising bacteria secreted insoluble ferric (Fe3+) oxides which protected from UV.
Once these bacteria died, they sank to the sea floor in a seasonal deposition of biogenic iron minerals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Hydrothermal vents remained active during the near-global ice cover of Snowball events. Why is this important in our understanding what happened in the immediate aftermath of the Snowball Earth events?

A

Provided a refuge for life that could survive the hot conditions by providing an environment away from the extreme cold.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why did oxygen levels and biological productivity rise after the end of each Snowball event?

A

BIFS…

Accelerated continental weathering, more river run off
Co2 in rain weathers rocks -> produces bicarbonate ions (HCO3-) which goes into oceans and increases biological productivity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What might have been the benefits which drove animals to develop the ability to produce mineralized skeletons?

A

Rising O2 and changing seawater chemistry
Larger body size needed support
Hardened excreted waste Ca?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Graptolitic black shale facies provide very particular palaeoenvironmental information: what is this, and why?

A

They were deposited under anaerobic conditions.

Oceanic circulation slower- oxygen didn’t reach sea floor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can palaeomagnetism be used to date ocean crust?

A

Magnetic minerals can crystallise in certain rocks

They align to orientation of magnetic field lines at the time rock forms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain what is meant by the term ‘homeomorph’, and describe two modern-day examples of homeomorphs.

A

Two different species adapt to same conditions despite being in different locations.
Penguins and puffins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

By comparison with a life in the water, what were the advantages for plants which made the transition to life on land?

A

CO2 more easily extracted from air than H2O
light levels higher in air than H2O, more efficient photosynthesis
empty ecospace
fewer competitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How did plants which adapted to life on land cope with the problems of nutrient supply and support?

A 
Cuticle increases diffusion distance
Formed branching axes
Photosynthesis by aerial shoots
Roots for anchoring and water uptake
Xylem and phloem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What information does the Rhynie Chert provide us with to indicate that terrestrial ecosystems were becoming increasingly complex by the early Devonian.

A

3D cell preservation in life position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain how mountain-building processes might drive the Earth towards global glaciations.

A

Large positive excursion in δ13C in organic matter and carbonates (CaCO3)
Caledonian mountain building increased weathering on land
weathering produced HCO3-
washed into ocean, locked up as carbonates on seafloor
reduced CO2atm cooling glaciation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Account for the two-step nature of the end-Ordovician extinction event.

A

Step 1…
cooling, water locked up in ice sheets sea level fall of up to 100m
epicontinental seas shrank or disappeared, killed shallow water faunas: 1st extinction

Step 2…
Gondwana began to migrate away from the south pole
ice sheets began to melt
ocean circulation slowed
world ocean returned to stratified, low-oxygen state
high-oxygen survivors of the first extinction were decimated: 2nd extinction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are lowland swamps an inappropriate analogue for Carboniferous coal-forming environments, and what type of environment is a better modern analogue?

A

Too little organic carbon (‘peat’) can build up to produce the thickness of coal seen in the Carboniferous

Rivers switch channels laterally: cover swamps with sediment before enough peat can build up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain the problems involved in reconstructing whole-plant morphology from plant fossils.

A

Plants produce many different organs throughout their lifespans
Organs separate during life and death
Each organ can be found as an individual fossil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The Carboniferous was a time of innovation in plant reproductive methods. Explain the changes in reproductive strategies in homosporous, heterosporous and seed plants.

A 
Produced separate male and female reproductive structures
♀ megaspores at bottom
♂ microspores at top
heterospory
could cross- and self-fertilise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain why volcanism alone cannot explain the stable carbon isotope excursion marking the late Permian extinction, and what other mechanisms are likely to have played a role in producing such a negative excursion?

A

Even volcanic CO2 at -7 ‰ wouldn’t produce the magnitude of the -ve excursion
adding all dead organic carbon (-25-30 ‰) after extinction, still wouldn’t produce excursion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why did atmospheric oxygen levels drop so dramatically in the late Permian, and what consequences did the atmospheric changes have for land-living animals?

A

CO2 atm crashed Dev- Carb: plants locking it up in soils/coals
whilst O2 atm) reached maximum in Carboniferous
but by end Permian: CO2atm rose due to erosion of coals and massive, sustained volcanism
O2 plummeted as CO2 , more lost through oxidation of CH4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What tell-tale rock types in the geological record might be recognised as representing the earliest stages of continental break-up, and why?

A

Igneous- continents move apart- volcanoes?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For many years it was thought that it would never be possible to determine the actual colour patterns of dinosaurs, but new discoveries in recent years has proven that we can: explain how, for certain specimens, it is now possible to reconstruct the colouration of extinct dinosaurs.

A

Some fossil feathers preserve pigment cells (melanosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Dinosaurs did not roar, they probably quacked or ‘cooed’ – what palaeontological evidence is there to substantiate this statement?
If birds are descended from dinosaurs… in 2016 the first Late Cretaceous bird vocal organ (syrinx) was found did dinosaurs also have the same vocal organs?
26
What evidence is there for many dinosaurs having a physiology more akin to endotherms than ectotherms?
Endotherms consume more food endotherms require >10x more food as ectotherms of same body mass look at population structure
27
What advantages may have driven vertebrates to return to a life in the sea?
More food and fewer predators Low reptilian metabolic rate good aquatically, despite needing to breath air Moving in water takes only 25% of the energy required by land animals
28
Explain the way in which ichthyosaur swimming methods changed from the Triassic to the Cretaceous.
Whole body flexed like an eel in early ichthyosaurs THEN swimmers Flexed rear body/tail
29
What drove the development of the mid-late Cretaceous greenhouse climate, and what were the effects of this on sea-level and ocean circulation?
Massive increase in volcanic activity Increased Co2 flux in atmosphere- 4-6x that of today High sea level meant less land area = low relief = silicate weathering = less co2 removal In the mid and late cretaceous the poles were not cold. Driven by deep water produced by sinking dense saline water from tropics?
30
How does mid-ocean ridge activity exert an influence on ocean water chemistry, and what bearing has this on organisms with mineralized skeletons?
Less oxygen delivered to deep ocean Less oxygen dissolves in warm water Global scale deposition of organic carbon
31
What palaeontological data provides evidence that greenhouse conditions prevailed in the mid to late Cretaceous world?
Oxygen isotopes from calcareous fossils Angiosperm lead shape Distribution of fossil organisms
32
Explain both the short-term and long-term environmental/ecosystem impacts of the Cretaceous-Tertiary bolide impact.
``` Bolide punches hole in atmosphere “vacuum tunnel” super-hurricanes or ‘hypercanes’ Heating Acid rain Dust and darkness ```
33
What were the factors which led to the termination of the Cretaceous-Paleogene greenhouse and the Oligocene development of icehouse conditions?
``` Africa and Europe collide India began drift north in Cretaceous collided with Asia Himalaya/Tibetan Plateau rose ~34Ma? massive uplift accelerated erosion and weathering 50x ‘sucked’ CO2 out of the atmosphere ```
34
What are the morphological differences between mammals and reptiles?
Mammals- mammary glands Hair reptile jaw bones become mammal ear bones differentiated teeth – molars, canines, incisors
35
What potential advantages would a bipedal life style have offered early hominids?
more open grassland height advantage: watching for predators, etc. travel further using less energy: food collection over wider area use arms/hands being upright dissipates excess body heat and reduces absorption of solar radiation
36
Compare and contrast the ‘Out of Africa’ and ‘Multiregional’ hypotheses of the evolution of Homo sapiens.
Out of Africa all hominin remains so far restricted to Africa… Homo erectus was first to migrate out of Africa < 2 Ma reached Indonesia by ?1.6-1 Ma (Java Man, etc.) Multiregional The multiregional hypothesis states that independent multiple origins (Model D) or shared multiregional evolution with continuous gene flow between continental populations.
37
We were not alone: what evidence is there for interbreeding of at least three different hominid species early in modern human history?
Humans share DNA with Neanderthals and Denisovans
38
Describe the process by which the Earth’s oceans became saline.
Erosion of the first oceans on sediments
39
Describe the classic experiments of Miller and Urey and explain why they are not now believed to have used exactly the right initial conditions to synthesise complex organic compounds.
1950’s - Replicating similar conditions of early Earth’s atmosphere – showing some organic compounds could be formed by having a mix of similar gases in an apparatus over a pool of water, introducing electrode (lightning) and UV light, eventually organic amino acids had formed from inorganic materials, they assumed early atmosphere was reducing and anoxic, however H2O+UV=free O2.
40
Explain the role of the ice-albedo feedback loop in the development of Snowball Earth events.
Ice has a very high albedo (reflectivity) therefore the bigger ice surface area, the more sunlight is reflected back into space and not absorbed on Earth, so can be responsible for dramatically lowering overall temperatures, and creating larger ice spread, like the snowball earth events.
41
Explain the difference between palaeomagnetic declination and palaeomagnetic inclination, and why the latter can be used to estimate the palaeolatitude at which rocks formed.
Declination – the angle pointing to magnetic North Inclination – Orientation tilts with latitude, following lines of magnetic force = preserved by mag minerals in rocks as deposited, can calculate latitude in which rocks were deposited
42
Describe the changes shown by the stable carbon isotope curve during a Snowball event - what did this signify?
Drop in carbon isotope signature - as planet froze – bio productivity plummeted
43
Describe the differences between late Proterozoic and Cambrian ecosystems.
Protoerozoic (late) (Edicaran) – cyanobacteria, photosyn. Primary producers, sponges, heterotrophic filter feeders Cambrian ecosystems – much more diversity and abundance – mobile multicellular animals, heterotrophic browsers and grazers, stromatolites decrease due to grazing pressure, first mineralized hard parts appear
44
Although exceptionally preserved fossil assemblages containing soft-bodied organisms have revolutionised our understanding of the Cambrian biota, they have also created problems with reconstructing extinct organisms. Explain the problems with reference to the anomalocarids and lobopods.
Shape of organisms difficult to tell which way up organism was or what body part was which as there weren’t any vertebrates or distinctive body part differences (anomalocarids were orginially seen upside down and believed that was the right way up)
45
What morphological innovation in arthropods and particularly trilobites may have served as a spur to drive evolutionary diversity in the early Cambrian, and why was this the case?
Eyes/vision – compound eyes – sensitive to motion and stereoscopic vision – able to see to prey and therefore have competitive advantage for survival
46
Describe how an accretionary prism forms and by providing an example from the British Isles, demonstrate how such geological phenomena provide contrasting younging information.
Sediment scraped off a subducting plate – fault-bounded slices of sediment form accretionary prism – each slice youngs away from trench but whole prism youngs towards trench, e.g Southern Uplands.
47
Provide an explanation of the term ‘exotic terrane’, and provide an example of one such terrane in the British Isles.
Volcanic island chains, continental fragments and oceanic plateaux are too buoyant to subduct therefore weld onto the edge of continental margins as exotic terranes e.g Grangegeeth (Eire) rocks onto edge of Laurentia
48
The unusual rock sequences in South Mayo, Ballantrae and the Lizard are examples of what type of geological phenomenon and how does one form?
Caledonian Orogeny and Variscan Orogeny (mountain building) – continental masses colliding
49
The evolution of larger, more deeply rooted plants had a profound influence on the nature of the global carbon cycle: how?
Larger plants/trees = locks up more CO2 levels and produces more O2, encourages wildfires, produces charcoal, locks up more CO2, plummeting levels even more
50
Compare and contrast the nature of ocean circulation in the early Palaeozoic with that of the present day.
No global conveyor belt, slow, sluggish circulations driven by brines sinking in equatorial areas – nutrient-rich, oxygen-poor, warm saline deep waters
51
Explain how a positive stable oxygen isotope (δ18O) excursion is produced by global glaciation.
Fluctuations depending on temp and ice volume – 16O, sea water evaporates lighter isotopes, rain out and locked up as snow/ice therefore 18O rich oceans
52
How did the proliferation of woody plants and trees change the global carbon cycle and drive the Earth into a series of global glaciations in the late Carboniferous and early Permian?
Larger plants/trees = locks up more CO2 levels and produces more O2, encourages wildfires, produces charcoal, locks up more CO2, plummeting levels even more
53
Why would limbs have first evolved in aquatic vertebrates long before tetrapods invaded land?
In order to support the body and adapt from the gravity-neutral environment.
54
What skeletal adaptations would be required for an aquatic vertebrate to be able to make the transition to a life on land?
Strong legs/feet and strong attachments to skeleton, pelvic bone expansion, more robust and connected to the backbone, ankle and digits develop, fins attach to shoulder bones, ribs enlarge to support shoulder and backbone, skull disconnects from shoulder bones, neck develops, wrist and digits develop, earbones develop from reduction of jaw bone
55
How did the near-equatorial location of the British Isles in the Permian produce the right geological phenomena that gave rise to the Southern North Sea gasfields?
Hydrocarbon reserves produced – bury coal under more sediment, geothermal gradient ‘bakes’ it, when the coal is of the right type, gas is given off, drives off methane and produces ‘natural gas’
56
Unlike amphibians, reptiles do not need access to water bodies in order to complete their life cycle: why?
They can produce an amniotic egg.
57
How might the ‘sails’ of the synapsids have been used by these ecothermic animals?
As animal increases size: volume3, area2 ectotherms, external heat sources sail increases area, blood supply solar panel, radiator
58
The failed arms of triple junctions are often sites of economically important geology: why is this?
Later become locations of major river systems
59
Why is oil and gas usually found in reservoir rocks above the source horizons, and, citing an example, under what circumstances can the hydrocarbons accumulate in reservoir rocks below the source?
Oil & gas have low densities, occupy more space than source material, & are thus buoyant Migrate from source rock into porous/permeable rocks – ‘reservoirs’- upward migration
60
Describe the morphological characteristics which define dinosaurs, comparing and contrasting them with animals often mistakenly referred to as “dinosaurs”.
``` reptiles amniotic egg internal fertilisation all lived on land all walked on upright straight legs ```
61
Why did even the largest of dinosaurs produce only relatively small eggs?
Shell thickness- bigger egg is, the thicker the shell- embryo would need to be able to get through Gas diffusion- too thick a shell would mean inability
62
Most dinosaurs were likely ‘r-strategists’ when it came to reproduction. Describe what is meant by this term and outline the likely advantages that stemmed from such reproductive methods.
Lots of young, little care high mortality? large mammals, e.g., elephant ~12 young/lifetime
63
How do we know that feathers did not evolve for flight, and for what purposes may they originally have been used?
``` ...but symmetrical feathers therefore not for flight… insulation? foraging? display? ```
64
Explain how and why reef-building communities have changed so dramatically over time
Reefs are very fragile and have declined massively over time through extinctions and widespread changes in atmospheric compositions/temperatures and sea chemistry
65
Describe how and why corals have been used as fossil ‘calendars’, and what these organisms have been able to tell us about
Show daily growth bands and more pronounced yearly band, work out days of year in geological past
66
Explain why ancient reef complexes in the geological record may be of economic importance
Lead-zinc ore deposits Hydrocarbon reserves Due to high porosity and permeability

Living Earth Quizzes (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions