Chapter 11

Question 1

biosphere

Answer 1

the part of the planet that contains all of it’s living organisms

Question 2

geobiology

Answer 2

the study of the interactions between the biosphere and Earth’s physical environment

Question 3

ecosystems

Answer 3

the organizational units of biological communities and their environments

Question 4

autotrophs

Answer 4

organisms that make their own food

Question 5

heterotrophs

Answer 5

feed directly or indirectly on producers

Question 6

metabolism

Answer 6

all the processes organisms use to convert inputs into outputs

Question 7

cyanobacteria

Answer 7

use photosynthesis to make carbohydrates

Question 8

respiration

Answer 8

organisms release the energy stored in carbohydrates

Question 9

biogeochemical cycle

Answer 9

the cycle where a chemical element or compound moves between the biological and environmental components of a system

Question 10

microorganisms

Answer 10

single-celled organisms

wherever there is water, these are present

Question 11

Three domains of life

Answer 11

bacteria
archaea
eukarya

Question 12

what is the youngest domain of life?

Answer 12

eukarya

Question 13

extremophiles

Answer 13

microorganisms that live in environments that would kill other organisms

Question 14

acidophiles

Answer 14

microorganisms that live in acidic environments

Question 15

thermophiles

Answer 15

microorganisms that live in extremely hot environments

Question 16

what temperature range do thermophiles thrive in?

Answer 16

50 - 70 degrees celsius

Question 17

examples of thermophile environments

Answer 17

hot springs

compost piles or landfills

Question 18

halophiles

Answer 18

microorganisms that live in highly saline environments

Question 19

anaerobes

Answer 19

microorganisms that live in environments completely devoid of oxygen

Question 20

example of biogeochemical cycle

Answer 20

phosphorous

• cycle between water and microorganisms
• cycle between rocks in mountains to sediments in the ocean

Question 21

mineral precipitation

Answer 21

indirectly - influencing the composition of the water around them
directly - in their cells as a result of their metabolism

Question 22

mineral dissolution

Answer 22

elements like sulfur and nitrogen can be readily available from natural waters in dissolved form

Question 23

chemoautotrophs

Answer 23

autotrophs that derive their energy from the chemicals produced when minerals dissolve

Question 24

biogeochemical cycle of pyrite

Answer 24

• iron and sulfur precipitate as pyrite
• when layers of sediments are deposited, pyrite is buried
• returns to the surface through plate tectonics
• rocks start to weather and the iron and sulfur are dissolved back into the water

Question 25

microbial mats

Answer 25

layered microbial communities

Question 26

microbial mat structure

Answer 26

top - oxygen-producing cyanobacteria that uses photosynthesis - aerobic
second - anaerobic heterotrophs that derive their food from the organic matter produced in the above layer

Question 27

stromatolites

Answer 27

rocks with distinctive thin layers

Question 28

what forms stromatolites?

Answer 28

many microbial mats

Question 29

how old is the Earth?

Answer 29

4.5 billion years old

Question 30

what does evolution say about microorganisms?

Answer 30

they evolved from a universal ancestor with genetic information

Question 31

prebiotic soup hypothesis

Answer 31

• early planetary materials might contain amino acids

- amino acids could have formed on a planet without oxygen

Question 32

when do most geobiologists think life on Earth began?

Answer 32

3.5 million years ago

Question 33

chemofossils

Answer 33

chemical remains of organic compounds made by ancient microorganisms

Question 34

when did photosynthesis become an important metabolic process?

Answer 34

2.7 billion years ago

Question 35

evolutionary radiation

Answer 35

rapid development of new types of organisms from a common ancestor

Question 36

Cambrian explosion

Answer 36

• 542 million years ago a radiation of animals during the Cambrian era
• every major animal group that exists on Earth today appeared in less than 10 million years

Question 37

hypotheses for the cause of the Cambrian explosion

Answer 37

• multicellularity opened up new evolutionary possibilities

- development of shells and skeletons triggered diversification

Question 38

when did dinosaurs go extinct?

Answer 38

65 million years ago

Question 39

when did the Paleocene-Eocene mass extinction occur?

Answer 39

55 million years ago

Question 40

what was the Paleocene-Eocene mass extinction?

Answer 40

the oceans released an enormous amount of methane (greenhouse gas) into the atmosphere

Question 41

how did the Paleocene-Eocene mass extinction occur?

Answer 41

the temperatures on Earth were rising which cause the frozen methane on the sea floor to turn into a gas and bubbled at the surface of the ocean

Question 42

what was the mother of all extinctions?

Answer 42

the mass extinction at the end of the Permian Period and the Paleozoic era

Question 43

what are the essential ingredients for life?

Answer 43

water and carbon

Question 44

where are we looking for life and why?

Answer 44

we are looking on Mars because water is present in ice form

Question 45

habitable zone

Answer 45

the distance from a star at which water is stable as a liquid