Quiz 4-6 Answers

Front 1

we have learned about the late heavy bombardment by studying..

Back 1

craters on the moon and rocks returned by the Apollo astronauts

Front 2

the argon that exists in the earth's atmosphere today

Back 2

accumulated over time from the decay of potassium

Front 3

the productions of our protective ozone later was enabled by

Back 3

the dissipation of hydrogen form the earth's atmosphere`

Front 4

to learn a rock's age, we must

Back 4

measure the ratio of different isotopes within it

Front 5

suppose that jupiter didn't exist and there was no planet in the solar system between mars and saturn. how might this have affected the earth?

Back 5

earth would most likely have been hit by more comets

Front 6

which of the following ideas gives us the most confidence that there could be life on planets around other stars

Back 6

the laws of physics and chemistry seem to apply everywhere

Front 7

which of the following is not a greenhouse

Back 7

nitrogen

Front 8

a rock's type (igneous, metamorphic, sedimentary) tells us

Back 8

how it's made

Front 9

the greenhouse effect refers to molecules in the atmosphere that absorb

Back 9

infrared radiation

Front 10

which of the following was a major component in the atmosphere of early earth?

Back 10

carbon dioxide

Front 11

radiometric dating now allows us to determine earth's age to the accuracy of about

Back 11

40 million years

Front 12

the timing of the last sterilizing impact is important because it probably tells us

Back 12

when life could have take long-term hold on the earth

Front 13

how did oxygen become so abundant in the earth's atmosphere

Back 13

it was released by life through the process of photosynthesis

Front 14

were it not for the greenhouse effect, the earth's average temperature would be

Back 14

somewhat lower (10s of degrees)

Front 15

the primary reason that earth has retained a lot of internal heat is because of its

Back 15

relatively large size

Front 16

the earth has far less carbon dioxide in its atmosphere than does venus because

Back 16

earth's carbon dioxide is locked up in carbonate rocks

Front 17

the term "snowball earth" refers to

Back 17

one in a series of very deep ice ages that occurred more than 500 million years ago

Front 18

earthquakes are important tools for geologists because the resulting vibrations

Back 18

allow the study of the earth's internal structure

Front 19

if earth had more greenhouse gases in its atmosphere, it would

Back 19

heat up

Front 20

which of the following serves as evidence that the earth's interior is not solid

Back 20

plate tectonics and the magnetic field

Front 21

which of the following applies to dna

Back 21

it stands for deoxyribonucleic acid

it is the basis for heredity

it transfers information from one generation to the next

Front 22

a covalent bond is

Back 22

when a pair of electrons is being shared between two atoms

Front 23

life on earth uses how many different amino acids

Back 23

20

Front 24

which is not a key property to life

Back 24

the ability to violate the second law of thermodynamics

Front 25

natural selection is the name given to

Back 25

the mechanism by which advantageous traits are preferentially passed on from parents to offspring

Front 26

the RNA molecule uses ___ while the DNA molecules uses ___

Back 26

uracil, thymine

Front 27

in a DNA molecule, the base cytosine connects to

Back 27

guanine

Front 28

people belong to which kingdom

Back 28

eukarya

Front 29

in a methane molecule, how many pairs of electrons is the carbon atom sharing with other atoms?

Back 29

4

Front 30

the earth's atmosphere began to accumulate oxygen about 2.5 Gyr ago. the principle agent responsible for the oxygen was

Back 30

cyanobacteria (blue-green algae)

Front 31

there are approximately how many base pairs in human DNA

Back 31

10^9

Front 32

based on DNA studies, it seems that all life on earth

Back 32

shares a common ancestor

Front 33

how did oxygen get into the earth's atmosphere

Back 33

it was released by life through the process of photosynthesis

Front 34

which of the following is not a source of energy for at least some forms of life on earth

Back 34

energy release from plutonium

Front 35

which of the following plays little role in allowing for life to flourish on the earth

Back 35

the moon protects life from most cosmic rays

Front 36

an organisms heredity is encoded in

Back 36

DNA

Front 37

silicon has been suggested as a basis for life because

Back 37

a silicon atom makes four molecular bonds as does a carbon atom

Front 38

which of the following is not true about prokaryotes

Back 38

all forms require oxygen

Front 39

what is the key observational evidence that supports the idea that life on earth has evolved through time

Back 39

the fossil record, revealed in geological layers of different ages, shows that life on earth has become more complex over time

Front 40

which of the following is not an argument for the superiority of water over ammonia or alcohol for supporting life

Back 40

water is found in the interstellar medium but alcohol and ammonia are not

Front 41

what molecules were created in the miller-urey experiment

Back 41

amino acids

Front 42

in the miller-urey experiment, the initial compositition of the gases was

Back 42

ammonia, methane, and water

Front 43

currently, we think the miller-urey experiment might not replicate the early earth accurately because

Back 43

our understanding of the early earth's atmosphere has changed

Front 44

the earth's atmosphere began to accumulate oxygen about 2.5 Gyr ago. the principle agent responsible for the oxygen was

Back 44

cyanobacteria (blue-green algae)

Front 45

we think the organics found in the tagish lake meteorite were formed

Back 45

in a cold dark molecular cloud

Front 46

in the tagish lake meteorite, the fact that the organix molecules were formed before the solar system was established by

Back 46

examining the isotopic ratios of certain elements

Front 47

how did oxygen get into the earth's atmosphere

Back 47

it was released by life through the process of photosynthesis

Front 48

we're not yet capable of detecting life on planets around other stars. however, as our technology develops, our first real chance of detecting life will probably come from

Back 48

examining spectral lines in the atmosphere of distant planets

Front 49

the origin of life on earth most likely occurred

Back 49

between 4.5 and 3.5 billion years ago

Front 50

the first living organisms were probably

Back 50

cells without nuclei that used RNA as their genetic material

Front 51

the importance of the miller-urey experiment is that

Back 51

it showed that natural chemical reactions can produce the building blocks of life

Front 52

early life arose in an oxygen-free environment, but if any of these microbes had come in contact with oxygen, the most likely effect would have been

Back 52

they would have been killed

Front 53

what is the evidence that all living organisms have evolved from a common ancestor

Back 53

essentially all life uses the same genetic code

DNA shows remarkable similarities among all life forms

not only useful but also "junk" DNA is found to be similar among different organisms

Front 54

the cambrian explosion refers to

Back 54

a dramatic increase in animal diversity beginning about 545 million years ago

Front 55

how did life arise

Back 55

DNA studies suggest that the first life may have lived in hot water near volcanic vents

&

this is a subject of scientific study

Front 56

"RNA world" refers to

Back 56

the idea that RNA was life's genetic material before DNA

Front 57

which of the following could be the most likely benefit from creating artificial life

Back 57

we'll gain insight into the origin of life on earth

Front 58

the hypothesis that an asteroid impact killed the dinosaurs seems to be

Back 58

well-supported by the geological evidence

Front 59

lets say you invent a laser system that can protect the earth from tunguska-sized impacts. about how often would you have to use it

Back 59

ever few hundred years

Front 60

based on DNA studies, it seems that all life on earth

Back 60

shares a common ancestor