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B6: Quiz 12 – Answers
B6: Quiz 12 – Answers
1)
a) The 5 factors are organic material, oxygen, water (or moisture), warmth and decomposers
b) A preservation fossil
c) Any 2 from:
2)
a) Fossil evidence supports Darwin’s theory that more complex life has evolved from simpler life forms because we find fossils of simpler organisms in older rocks and fossils of more complex organisms in younger rocks. This shows that simpler organisms have evolved to become more complex organisms
b) We cannot use fossil evidence to prove how life began on earth because there are gaps in the fossil records. The gaps in the fossil records exist because many of the early life forms were soft-bodied, which meant that few traces were left behind. The traces that were left behind were mainly destroyed by geological activities (earthquakes). This has resulted in an incomplete fossil record, which means that we cannot use fossils to conclusively say how life began on earth
3)
a) Extinction is when a species does not exist anymore
b) The five factors are:
a) The 5 factors are organic material, oxygen, water (or moisture), warmth and decomposers
b) A preservation fossil
c) Any 2 from:
- Glaciers – it is too cold for decomposers
- Peat bogs – too acidic for decomposers
- Amber/ tree resin – no oxygen or water (moisture) for decomposers
- Replacement by minerals – certain hard parts of organisms do not decay quickly when they are buried (teeth, bones and shells). When these parts do decay, they are replaced by minerals, which creates rock-like substances in the same shape as these hard parts of the organism. These rock-like substances are clear to see when the sediment surrounding the organism has also turned to rock
- Traces – traces of organisms can sometimes be found when they are covered by sediment that later becomes rock. These traces can be footprints, burrows and rootlet traces (plant roots). Traces can be referred to as casts and impressions.
2)
a) Fossil evidence supports Darwin’s theory that more complex life has evolved from simpler life forms because we find fossils of simpler organisms in older rocks and fossils of more complex organisms in younger rocks. This shows that simpler organisms have evolved to become more complex organisms
b) We cannot use fossil evidence to prove how life began on earth because there are gaps in the fossil records. The gaps in the fossil records exist because many of the early life forms were soft-bodied, which meant that few traces were left behind. The traces that were left behind were mainly destroyed by geological activities (earthquakes). This has resulted in an incomplete fossil record, which means that we cannot use fossils to conclusively say how life began on earth
3)
a) Extinction is when a species does not exist anymore
b) The five factors are:
- A disease kills them
- A new predator kills them
- The environment changes too quickly
- They cannot compete with another species for resources like food, light, water etc…
- An event kills them like an asteroid strike, a tsunami or a volcanic eruption
- Overhunting animals for either food or resources
- Habitat loss to make room for cities, farmland or the resources that are on the land
- Pollution, which can involve acid rain, oil spills, plastic pollution etc.
- Climate change, which is causing global temperatures to rise, ice caps to melt, weather patterns to change (more frequent and more intense tropical storms and droughts)
Questions
1)
a) What are the 5 conditions needed for decay to take place?
b) If one or more of these 5 conditions are not present, decay will not take place and a fossil will be produced. What is the name of the type of fossil that will be produced?
c) Give 2 examples of places where these types of fossils are produced and give the reason why each of the fossils are produced.
d) Give a brief explanation of the two other ways that fossils can be produced.
2)
a) What fossil evidence is there to prove Darwin’s theory that more complex life evolved from simpler life forms?
b) Why are we unable to use fossil evidence to conclusively say how life began on earth?
3)
a) What does extinction mean?
b) Give the five factors that can lead to the extinction of a species.
c) Humans are the main reason behind the extinction of certain species today. Give 3 reasons why.
1)
a) What are the 5 conditions needed for decay to take place?
b) If one or more of these 5 conditions are not present, decay will not take place and a fossil will be produced. What is the name of the type of fossil that will be produced?
c) Give 2 examples of places where these types of fossils are produced and give the reason why each of the fossils are produced.
d) Give a brief explanation of the two other ways that fossils can be produced.
2)
a) What fossil evidence is there to prove Darwin’s theory that more complex life evolved from simpler life forms?
b) Why are we unable to use fossil evidence to conclusively say how life began on earth?
3)
a) What does extinction mean?
b) Give the five factors that can lead to the extinction of a species.
c) Humans are the main reason behind the extinction of certain species today. Give 3 reasons why.