Changes In Biodiversity Over Time

Question 1

What are 4 main conditions required for fossilization?

Answer 1

Rapid burial, slow decomposition, further burial, left undisturbed

Question 2

What did animals walk on land?

Answer 2

440-410 mya

Question 3

When did mammals first appear?

Answer 3

160 mya

Question 4

when did flowering plants first appear?

Answer 4

130 mya

Question 5

When did multicellular organisms begin to appear?

Answer 5

600 mya

Question 6

What are trace fossils?

Answer 6

fossils that show evidence of the existence of an organism, like a footprint

Question 7

What are mould fossils?

Answer 7

Fossilized impressions of remains imprinted on rock

Question 8

What are cast fossils

Answer 8

Mould fossils that have been filled in by minerals

Question 9

What is the half-life of carbon 14?

Answer 9

5730 years

Question 10

How old do fossils have to be to for carbon dating to be used?

Answer 10

less than 50,000 years

Question 11

How does carbon dating work?

Answer 11

Carbon 14 isotope decays at a known rate to the more stable nitrogen 14. The ratio of C12: C14 is measured in fossils and then used to determine the age of the fossils based on carbon 14s half-life.

Question 12

What is potassium dating best used for and why?

Answer 12

very old fossils, as potassium 40 has a half-life of 1.25 billion years

Question 13

What does potassium 40 decay to?

Answer 13

Argon 40

Question 14

What is the difference between absolute and relative dating techniques?

Answer 14

Absolute dating techniques give an exact age of the fossil whereas relative dating techniques give an age of a fossil relative to other fossils.

Question 15

What are index fossils?

Answer 15

Fossils of species that are known to have lived within

a specific and short time period

Question 16

Why are index fossils useful?

Answer 16

They enable you to compare fossils of known age to those of unknown to get a relative age

Question 17

What is stratigraphy?

Answer 17

Estimating rock age, based on rock layer position

Question 18

What are homologous structures?

Answer 18

Features in different species with different functions but the same structure

Question 19

What are analogous structures?

Answer 19

Features in different species with the same function but the different structure

Question 20

What do homologous structures show?

Answer 20

that the organisms shared a recent common ancestor (divergent evolution)

Question 21

What do analogous structures show?

Answer 21

that environment impacts evolution. (convergent evolution)

Question 22

What are vestigial structures?

Answer 22

structures in a species that had a function in an ancestor but have little function in the current organism

Question 23

What does developmental biology show?

Answer 23

That when there are similarities between different species embryo’s they share a similar developmental gene and hence have a recent common ancestor

Question 24

What occurs during convergent evolution?

Answer 24

When 2 species which different common ancestors develop similar traits as a result of similar selection pressures

Question 25

What occurs during divergent evolution?

Answer 25

When 2 species of the same common ancestor develop different traits as a result of different selection pressures

Question 26

Define extinction

Answer 26

When all members of a species permanently die out and no longer exist

Question 27

Define background extinction

Answer 27

The standard rate at which species become extinct

Question 28

Define mass extinction

Answer 28

A period of time during which an abnormally high number of species died out in a short time span.

Question 29

What is an effect of mass extinction?

Answer 29

It can allow surviving species to expand and diverge

Question 30

How does an organism develop an adaptation?

Answer 30

Through inheriting different traits from its parents.

Question 31

Can individual organisms adapt to their environment?

Answer 31

No, they can adjust but only the species as a whole can develop adaptations over time

Question 32

Where do your traits stem from?

Answer 32

Your genes

Question 33

What is the extinction of the dinosaurs an example of?

Answer 33

Mass extinction

Question 34

How did the dinosaurs going extinct, affect other species?

Answer 34

It allowed mammals to expand and diverge