Z-Bio Exam

Front 1

Origin of Earth (6 things)

Back 1

-Hot molten earth formed from galactic gas, dust and meteorites about 4.6 billion years ago.
-Meteor bombardment continues as earth cools.
-Large meteor hits earth, knocks earth into present tilt and blasted debris into space to form moon.
-Surface of earth replaced through volcanic activity.
-Moon has no volcanic activity and preserves craters from early meteor bombaqrdment.
-Oceans, lakes and rivers form once earth cools below 100°C.

Front 2

Origin of Life

4 parts

Back 2

1-Early atmosphere
2-Origin of Macromolecules
3-RNA World
4-First Cell

Front 3

Early atmosphere

Back 3

Early atmosphere
Composed mostly of nitrogen, carbon dioxide and water with lesser amounts of hydrogen,
ammonia, hydrogen cyanide, hydrogen sulfide and methane.
Highly reducing (NO oxygen present)

Front 4

Origin of Macromolecules

Macro=miller

Back 4

Origin of Macromolecules

Miller experiment shows (early atmosphere + heat, condensation and lightning) can produce
many amino acids, nucleic acid bases and sugars.

Front 5

Extraterrestrial origin (Macromolecules)

Back 5

certain kinds of meteorites contain organic molecules

Front 6

Evaporation (e.g. in rock pools)
(Macromolecules)

Back 6

concentrates simple amino acids, sugars and bases allowing
polymerization to form simple proteins and nucleic acids.

Front 7

RNA World RNA- Ribsomes (5 functions)

Back 7

Certain RNAs called ribozymes can catalyze reactions (The catalytic machinery used by a
ribosome during protein synthesis is RNA)
-can be evolved in the test tube to catalyze many chemical reactions.
-A primitive RNA capable of catalyzing its own synthesis may have been the first self-replicating
"Life-Form."
-RNA has genetic information and carries out catalysis (has phenotype)
-Later, DNA takes over role of genotype and proteins used for catalysis (i.e. enzymes)

Front 8

First Cell

Back 8

Phospholipids (phosphate - glycerol - 2(fatty acid)s) readily form liposomes (vesicles surrounded
by a membrane composed of a bilipid layer). Plausible origin of the first cell memebrane.

Front 9

First Evidence of Life

Back 9

First hint of life - carbon granules embedded in 3.85 million year-old rock has stable (i.e.
radioactive) 13C:12C isotope ratio characteristic of life rather than inanimate matter.

Front 10

First cellular life (5 aspects)

Back 10

First cellular life (5 aspects)


-Single celled
-Grew without oxygen (anaerobic)
-Heterotrophic (got carbon and energy from chemical environment)
-prokaryotic-like (like bacteria)
-aquatic

Front 11

First fossils

Back 11

First fossils - putative filamentous bacterium 3.4 billion years old in Apex chert, Australia
Stromatolite fossils 3.4 billion years old (certain living bacteria form stromatolites in Australia)

Front 12

Origin of Modern Atmosphere
5parts

Back 12

Cyanobacteria evolve photosynthesis
-Produces first gaseous oxygen in atmosphere.
-Oxygen is highly reactive chemical and would have been TOXIC
-Oxygen reacts with protein, DNA, RNA, lipid etc. so life not likely to originate again
-Origin of atmospheric oxygen accounts for banded iron formations at 2 billion years ago.

Front 13

Origin of Eukayotes

FF
FF
MIT
Chl

Back 13

Origin of Eukayotes

-First fossil alga about 1.2 billion years old
-First fossil animal embryos about 570 million years old
-Mitochondria were once free-living bacteria that were engulfed by a primitive eukaryote and the
two coevolved in a symbiosis.
-Chloroplasts were once free-living photosynthetic bacteria that were engulfed by a primitive eukaryote with a mitochondria and the three coevolved in a symbiosis.

Front 14

Mitochondria and chloroplasts have: 5 things

Bbcgg

Back 14

Mitochondria and chloroplasts have: 5 things

- bacteria-like protein translation machinery
-bacteria-like membranes
- circular DNA
- gene sequences most closely related to bacteria
(ribosome structure)
- grow by binary fission

Front 15

Origin of Multicellular Animals

Time?
What?

Back 15

Origin of Multicellular Animals

First arose about 600 million years ago - mostly red, green and brown algae

Front 16

Cambrian Explosion

Back 16

-rapid diversification of first multicellular animals about 540 years ago
- most modern phyla appear
- diversification associated with evolution of HOX genes controlling
development

Front 17

Phylum Chordata

Back 17

Have a notochord
Tail extends beyond anus

Front 18

Three main groups
(Phylum Chordata)

Back 18

-Urochordates - invertebrate, larval notochord lost in adults
-Cephalochordates - have a notochord and nerve chord but no vertebrae
-Vertebrates - have a nerve chord surrounded by a backbone and a cranium

Front 19

Vertebrates

Back 19

Vertebrates=

Lamprey and Hagfish are jawless (hagfish has a cranium but no vertebrae)
Earliest jawless fish fossils at 530 million years old in China

Front 20

Jaws

3 main points

Back 20

Major innovation - larger prey, defense, chomp, chomp, chomp
-Transformation of one structure into another - jaw evolved from gill arch supports
-Transformation of one function into another - breathing to eating, chomp, chomp, chomp

Front 21

Cartilaginous Fish

Back 21

rays and sharks have skeleton of cartilage

Front 22

Ray-finned fish

Back 22

Ray-finned fish= boney fish (walleye, tuna, etc.)

Front 23

Lobe-finned fish

Back 23

Lobe-finned fish=lungfish and coelacanth

Front 24

Moving onto land=6

m
s
t
b
r
r

Back 24

mobility
support
temperature control
breathing
resist desiccation
reproduction

Front 25

Amniotic Egg

4 characteristics
L
N
R
W

Back 25

Land egg
Waterproof skin
No larval forms
Reptiles displaced amphibians as dominant land tetrapods about 290-250 Ma

Front 26

Great Dying 250 Ma - Permian Extinction

Back 26

90% marine species wiped out, 2/3 reptiles and amphibians wiped out
Only known mass extinction of insects
Cause not known
Pangea forms in late Permian

Front 27

Age of Reptiles

What happends
what breaks
What emerges
What evolves

Back 27

Age of Reptiles

Pangea break ups into Laurentia and Gondwana (about 200 Ma) and split continues to todays
continents
Dinosaurs dominant tetrapod life form on land from 200 Ma to 65 Ma
Birds evolve from theropods (many transitional fossils with feathers, teeth etc.)
From about 100 Ma to 200Ma warm blooded mammals with hair, milk etc. gradually evolve
from reptiles over 100 million years.

Front 28

Cretaceous Extinction

Back 28

65 Ma
-All large land animals go extinct
-Most birds go extinct
>Asteroid hit earth just off the North Yucatan Peninsula in Mexico
/100 mile wide crater
/Many forest fires
/4 Km high tidal wave
/Dust and smoke in atmosphere blocks sun, earth cools, global winter.
/Mammals radiate