7-Science-Evolution-Final Study Guide- AQs

Question 1

When is an organism considered to be endangered?

Answer 1

When they have such a small population that they are in danger of becoming extinct.

Question 2

When is an organism considered to be extinct?

Answer 2

When there are no surviving members of that species

Question 3

Explain why scientists think the dinosaurs went exiting. When did this occur?

Answer 3

At least one enormous asteroid crashed into Earth 65 mya. This created a huge cloud of dust and debris that blocked out the sun’s light for a long period of time. This disrupted the food web, caused global cooling, etc.

Question 4

List two factors that contributed to the extinction of the mammoth.

Answer 4

End of the Ice Age and human hunting

Question 5

List two factors that have caused the decline of the Asian elephant.

Answer 5

Loss of habitat and human hunting

Question 6

How do we know about prehistoric organisms that lived thousands or millions of years ago?

Answer 6

study fossils

Question 7

What types of information can fossils provide about organisms?

Answer 7

What it looked like, how it lived, what and how much it ate, etc.

Question 8

What types of organisms are often preserved in fossils?

Answer 8

Organisms with hard body parts (bones, shells, exoskeletons); aquatic organisms

Question 9

List three examples of trace fossils.

Answer 9

Footprints, trails, borrows, egg shells, feces

Question 10

Describe the ground conditions for the footprints to have become preserved?

Answer 10

soft sediment; a layer of soil must have deposited fast enough to cover and protect the tracks

Question 11

What evidence do we need to know if larger prints come from larger/heavier organisms?

Answer 11

depth of the foot prints

Question 12

What is the difference between a observation and an inference? List an example of each from one of the footprint cards.

Answer 12

It is a fact that the larger tracks became more widely spaced (observation), but it is only a theory or interpretation that it meant that the organism started to run (inference)

Question 13

How do scientists determine how to divide geologic time into periods.

Answer 13

Based on the first or last appearance of certain fossils (index fossils)

Question 14

List two types of organisms that first appeared on Earth.

Answer 14

bacteria and algae

Question 15

List the time periods in order from the oldest to the most recent.

Answer 15

Precambrian (4.5 billion-550 million years ago)
Paleozoic (550-245 mya)
Mesozoic (245-65 mya)
Cenozoic (65 mya- present)

Question 16

Which time period represents the longest amount of time (84%)? Shortest (1%)?

Answer 16

Precambrian (longest)

Cenozoic (shortest)

Question 17

During which time period did life on Earth really diversify?

Answer 17

Paleozoic

Question 18

If you don’t find fossils from a particular organism, can you conclude that the organism did not exist during that time? Why or why not?

Answer 18

No! The soil conditions may not have been suitable for fossils to form.

Question 19

How can you determine if two organisms lived at the same time?

Answer 19

They are found in the same rock layer

Question 20

How can you use rock layers to determine which fossils are likely to be from an extinct species?

Answer 20

If they disappear form the fossil record and do not reappear

Question 21

Why do scientists creat stratigraphic columns?

Answer 21

As a record of the rock layers and fossils they observed in different locations

Question 22

Turtles compete with one another. A faster turtle is more likely to escape from a predator. Over many gyrations, the average speed of turtles increases. Give an explanation for Lamark and for Darwin.

Answer 22

Lamark: As turtles move to escape predators they become faster (they acquire speed). This trait is passed to offspring.
Darwin: Turtles vary in speed. The faster turtles are better able to escape predators than slow turtles; therefore, the fast turtles survive longer to reproduce (and pass on their genes for speed)

Question 23

Why is Darwin’s theory of evolution more convincing than Lamark’s?

Answer 23

We know (after studying genetics) that acquired traits are not passed to offspring.

Question 24

List two examples of animal adaptations.

Answer 24

Odor, camouflage, poison, speed, shells, sounds, etc.

Question 25

Explain the process of natural selection. Use giraffe neck length as an example.

Answer 25

A mutation in the giraffe popultation produced variation in neck length. Some giraffes had slightly longer necks than others. the giraffes with the longer necks have an edvantage in getting more food… allowing the giraffes to survive long enough to reproduce. Every generation, more longer-necked giraffes survive. Over time, the giraffe population comes to have the adaptation of longer necks

Question 26

List three factors that drive natural selection

Answer 26

Predators, prey (food), mates

Question 27

What allowed for the variation in fork bird beaks?

Answer 27

mutations

Question 28

Why is variation needed in the process of natural selection?

Answer 28

Creates competition (2-tined fork birds would be equally likely to get food)

Question 29

Why are organisms with little variation more at risk of becoming extinct?

Answer 29

Not much variation for natural section to act upon. If environmental change occurs and it negatively impacts one organism in a species, it would impact the entire species the same way.

Question 30

Are mutations always harmful? Use beaks as example.

Answer 30

No, a mutation creating a larger beak could allow birds to eat larger seads and nuts.

Question 31

What did Darwin notice when studying the Galapagos finches?

Answer 31

That they differed in size, color and beak shape/length (beak was adapted to food available)

Question 32

HOw did so many cichlid species come to exist in Lake Victoria?

Answer 32

Lake Victoria provides a large number of different habitats. Over time, the cichlides became so different that they were not able to reproduce successfully with each other (speciation)

Question 33

What do modern scientists use to compare similarities and differences among species

Answer 33

genetic evidence

Question 34

List two things you can learn about evolution by comparing fossil records?

Answer 34

The order dfferent animals evolved; how closely related one group of animals is to another; when animals went exting

Question 35

List two reasons that there are very few fossils from the Precambrian

Answer 35

There was nothing alive that easily fossilized; older ricks have been subjected longer to the various forces of nature (erosion, heat, and pressure of burial, etc

Question 36

Based on the graphs place the four different classes (reptile, fish, amphibian, and mammal) in order based on when they first appeared in the fossil record

Answer 36

fish, amphibian, reptile, and mammal

Question 37

What ae some possible explanations for the disappearance of a family from the fossil record?

Answer 37

Extinct, did not fossilize

Question 38

What could explain the appearance of a family in the fossil record?

Answer 38

Newly evolved, began to fossilize, large increase in the population

Question 39

Why is the Cenozoic Era often referred to as the Age of Mammals?

Answer 39

Mammals really increased in diversity (404 new families)

Question 40

Why is referring to the Cenozoic as the Age of Mammals misleading?

Answer 40

Many other animals thrived during this time period

Question 41

What kinds of skeletal changes appear to have occurred during the evolution of whales?

Answer 41

loss of hind limbs, front limbs change to fins, longer/stronger tail, more streamlined body

Question 42

What can you infer about the changes in habitat that occurred at the same time as skeletal whale changes?

Answer 42

Land animal
to land and shallow water animal
to water animal

Question 43

How does DNA provide evidence about how species are related?

Answer 43

The more similar the DNA sequence the more closely related two species are

Question 44

Draw a simple evolutionary tree that shows the evolution of reptiles fish and mammals

Answer 44

fish first, reptiles branch off of fish, mammals branch off of reptiles