Chapter 25: Part two

Question 1

Stromalites

Answer 1

• Oldest Fossil

- rocks formed by the accumulation of sedimentary layers on bacterial mats

Question 2

Photosynthesis & the Oxygen Revolution

Answer 2

O2 produced by oxygenic photosynthesis reacted with dissolved iron & precipitated out to form banded iron formations

Question 3

O2 began accumulating in the atmosphere

Answer 3

& rusting iron-rich terrestrial rocks

Question 4

The First Eukaryotes

Answer 4

Eukaryotic cells have a nuclear envelope, mitochondria,

endoplasmic reticulum & a cytoskeleton

Question 5

endosymbiont theory (related to Eukaryotic cells)

Answer 5

proposes that mitochondria & plastids (chloroplasts & related organelles) were formerly small prokaryotes living within larger host cells

Question 6

endosymbiont is a cell

Answer 6

that lives within a host cell

Question 7

Serial endosymbiosis

Answer 7

supposes that mitochondria evolved before plastids through a sequence of endosymbiotic events

Question 8

endosymbiotic origin of MITOCHONDRIA and PLASTIDS

Answer 8

Inner membranes are similar to plasma membranes of prokaryotes
- membrane bound organelles

Question 9

MITOCHONDRIA

Answer 9

photosynthetic bacterium

Question 10

Their ribosomes are more similar to prokaryotic

Answer 10

than

eukaryotic ribosomes

Question 11

The Origin of Multicellularity

Answer 11

evolution of eukaryotic cells allowed for a greater range of unicellular forms

Question 12

A second wave of diversification occurred

Answer 12

when multicellularity evolved and gave rise to algae, plants, fungi, and animals

Question 13

Cambrian Explosion

Answer 13

efers to the sudden appearance of fossils resembling modern animal phyla

Question 14

Burgess Shale

Answer 14

The fossils of the Burgess Shale in the Canadian Rockies preserve an intriguing glimpse of early life on Earth

Question 15

The Colonization of Land

Answer 15

Fungi, plants, and animals began to colonize land about 500 MYA

Question 16

Vascular tissue in plants transports

Answer 16

materials internally & appeared by about 420 MYA

Question 17

Plants and fungi

Answer 17

likely colonized land together

Question 18

Tetrapods

Answer 18

Mammals belong to the group of animals called

Question 19

Tetrapods evolved

Answer 19

from lobe-finned fishes

Question 20

Plate Tectonics

Answer 20

Earth’s crust is composed of plates floating on Earth’s mantle

Question 21

Tectonic plates move slowly

Answer 21

rough the process of continental drift

Question 22

Oceanic & continental plates can

Answer 22

collide, separate, or slide past each other

Question 23

Pangaea

Answer 23

Formation of the supercontinent

• A deepening of ocean basins
• A reduction in shallow water habitat
• A colder & drier climate inland

Question 24

Continental Drift

Answer 24

• continent’s climate changes as it moves north or south

- Separation of land masses can lead to allopatric speciation

Question 25

Ex. Similarity of fossils in parts of South America and Africa is consistent

Answer 25

with the idea that these continents were formerly attached

Question 26

mass extinction

Answer 26

the rate of extinction has increased dramatically and caused a

Question 27

Mass extinction is the result of

Answer 27

disruptive global environmental changes

Question 28

Permian Extinction

Answer 28

defines the boundary between the Paleozoic and Mesozoic eras about 250 MYA

Question 29

A number of factors might have contributed to these mass extinctions

Answer 29

- Intense volcanism in what is now Siberia - Global warming - ocean acidification

Question 30

Cretaceous Mass Extinction

Answer 30

Organisms that went extinct include - half of all marine species - many terrestrial plants and animals, including most dinosaurs

Question 31

Adaptive Radiation

Answer 31

is the rapid evolution of diversely adapted species from a common ancestor

Question 32

Heterochrony

Answer 32

is an evolutionary change in the rate or timing of developmental events.....

Question 33

Major changes in body form can result from changes in

Answer 33

the sequences and regulation of developmental genes

Question 34

Changes in Spatial Pattern

Answer 34

Substantial evolutionary change can also result from alterations in genes that control the placement and organization of body parts

Question 35

Homeotic genes

Answer 35

determine such basic features as where wings and legs will develop on a bird or how a flower’s parts are arranged

Question 36

Hox genes are a class of homeotic genes that provide positional information

Answer 36

during animal embryonic development

Question 37

Changes in Genes

Answer 37

Changes in developmental genes can result in new morphological forms

Question 38

Ubx gene have been identified

Answer 38

that can “turn off” leg development

Question 39

Changes in morphology likely result from

Answer 39

changes in the regulation of the expression of developmental genes