Bio 200 UB Exam Questions with
Complete Solutions
Time scales (3) - ANSWER-1) The formation of the earth
2) Measuring time on Earth
3) A brief tour through the history of time (on Earth)
Explain the steps of formation of earth - ANSWER-1) Universe
2) Solar system
3) Earth(and other planets)
Before the solar system there was - ANSWER-Protoplanetary disk (pre planet)
dust, rock, and gas (mostly made up of H & He- also heavy items from the super nova)
what happened to start the precurser to the sun forming? - ANSWER-4.6 bill years ago,
a star destroyed in supernova and the explosion sent a shockwave causing cloud from
the shockwave to accelerate then spin.
Most mass went inside the disk and concentrated in the middle which began to heat up.
Due to the concentration of mass that was the precourser to the sun forming
How did the sun form? - ANSWER-Pressure within the center of the protoplanetary disk
triggers nuclear fusion of H & He and gives us the sun!
How did planets form? - ANSWER-Gravity from sun forming causes matter to condense
around the previous proterbed objects that are in the protoplanetary disk ---> outside of
suns gravitational grasp so seperating into rings & becoming larger planets.
How did earth form? - ANSWER-Gravity outside the reach of the sun causes matter to
condense around protoplanets
What are the four main time periods in the Earth's history? - ANSWER-1)Precambrian
supereon
2)Paleozoic era
3) Mesozoic era
4) Cenozoic era
, Why is precambrian era called precambrian supereon? - ANSWER-So long, that we call
it a supereon
Precambrian supereon divides into? - ANSWER-Hadean eon
Archean eon
proterozoic eon
Explain Hadean eon - ANSWER--Completely molten
-No oceans (no water)
-no oxygen in atmosphere
-No protective atmosphere
(Earth being bombarded with planetoids & other material + residual heat from formation
of earth= earth became fully molten)
**water cycle beings at very end of this eon
How does the water cycle begin at the very end of Hadean eon? - ANSWER-At the end
of Hadeon eon, earth surface cools quickly & gets beginnings of solid crust.
Heavy astroidal bombarding caused cracks in crust ---> cracks + add gas from volcanos
= steam to escape
steam + gas = formation of 1st atmosphere.
Clouds formed from steam ---> rain formed ---> ocean formed
So the end of the Hadeon eon gets better...but...still - ANSWER--no free oxygen
( bound to other materials)
-no ozone layer yet
When is the first life form? - ANSWER-The end of the Hadean eon.
**just unicellular life is present for 3 bill years after first
Unicellular vs multicellular - ANSWER-unicellular dominated life on earth
When does multicellular life arise? - ANSWER-Late precambrien
What was found from the archean eon? - ANSWER-fossils of cyanobacterial mats and
stomatolites
fossils from Archea found too
bacteria fossils found
Complete Solutions
Time scales (3) - ANSWER-1) The formation of the earth
2) Measuring time on Earth
3) A brief tour through the history of time (on Earth)
Explain the steps of formation of earth - ANSWER-1) Universe
2) Solar system
3) Earth(and other planets)
Before the solar system there was - ANSWER-Protoplanetary disk (pre planet)
dust, rock, and gas (mostly made up of H & He- also heavy items from the super nova)
what happened to start the precurser to the sun forming? - ANSWER-4.6 bill years ago,
a star destroyed in supernova and the explosion sent a shockwave causing cloud from
the shockwave to accelerate then spin.
Most mass went inside the disk and concentrated in the middle which began to heat up.
Due to the concentration of mass that was the precourser to the sun forming
How did the sun form? - ANSWER-Pressure within the center of the protoplanetary disk
triggers nuclear fusion of H & He and gives us the sun!
How did planets form? - ANSWER-Gravity from sun forming causes matter to condense
around the previous proterbed objects that are in the protoplanetary disk ---> outside of
suns gravitational grasp so seperating into rings & becoming larger planets.
How did earth form? - ANSWER-Gravity outside the reach of the sun causes matter to
condense around protoplanets
What are the four main time periods in the Earth's history? - ANSWER-1)Precambrian
supereon
2)Paleozoic era
3) Mesozoic era
4) Cenozoic era
, Why is precambrian era called precambrian supereon? - ANSWER-So long, that we call
it a supereon
Precambrian supereon divides into? - ANSWER-Hadean eon
Archean eon
proterozoic eon
Explain Hadean eon - ANSWER--Completely molten
-No oceans (no water)
-no oxygen in atmosphere
-No protective atmosphere
(Earth being bombarded with planetoids & other material + residual heat from formation
of earth= earth became fully molten)
**water cycle beings at very end of this eon
How does the water cycle begin at the very end of Hadean eon? - ANSWER-At the end
of Hadeon eon, earth surface cools quickly & gets beginnings of solid crust.
Heavy astroidal bombarding caused cracks in crust ---> cracks + add gas from volcanos
= steam to escape
steam + gas = formation of 1st atmosphere.
Clouds formed from steam ---> rain formed ---> ocean formed
So the end of the Hadeon eon gets better...but...still - ANSWER--no free oxygen
( bound to other materials)
-no ozone layer yet
When is the first life form? - ANSWER-The end of the Hadean eon.
**just unicellular life is present for 3 bill years after first
Unicellular vs multicellular - ANSWER-unicellular dominated life on earth
When does multicellular life arise? - ANSWER-Late precambrien
What was found from the archean eon? - ANSWER-fossils of cyanobacterial mats and
stomatolites
fossils from Archea found too
bacteria fossils found
