NOVA- Origins: How Life Began

what perecent of earths history where there life on the surface of earth that you would see in the naked eye.

10%

tiny microbes raised the level of oxygen from less that one percent to today's ---- percent

21

when was earth born

4.5 billion years ago

the brown goo that formed in Stanley miller's lab was what?

Amino Acid

what cataclysm occurred that eventually led to the moon's formation?

The planet the size of mars hit earthearth

Amino acid

are compounds that form molecules when carbon and other elements link together and are the building blocks of proteins or (peptides), cells- which are the vital ingredients of all living things.

multi-cellular life that we are most familiar with- animals, plants and their environment- was made possible by the slow, toilsome task of ----- to oxygenate the -----

bacteria, atmosphere

Snottites acidity (ph) is that of

battery acid

named after the ----- - ----- color of their cells these cyanobacteria use photosynthesis to collect energy from the sun. they secrete a sticky coating to shield them from ----- radiation.

blue- green, ultraviolet

all living things are made up what chemical elements

carbon, oxygen, hydrogen, nitrogen- four of the mos common elements in the universe

blue-green cells that use photosynthesis to collect energy from the sun? the sticky coating does what

cyanobacteria; protects from ultraviolet rays

scientists found creatures of all types thriving in underwater volcanoes

despite scalding temp. acid eruptions and total lack of sunlight

Hydrogen sulfed can be

extremely poisonous so the scientists were masks inside the cave

Heavy bombardment

for about the firs 600 billion years, comments and asteroids (300 miles across) pounded our planet- a time known as

Earth was was covered in what? and smothered in what?

lava and noxious gas

what do you see in a magnifying piece of space dust?

mineral, carbon, and 4.5 billion years old

with the protection of the ---- layer, life was able to diversify into more complex ----.

ozone, organisms

amino acids, combinations of carbon and other basic elements had fused together to form more complex molecules called

peptides

when the atmosphere was thicker and dominated by CO2 the earth had a ------- tinge and the ocean had an olive ---- color.

redish, green

Earth is a place that is ------ and ------ by life.

shaped and modeled

over time, ----- spread out across the -----. As a byproduct of photosynthesis the ancient bacteria formed a waste product:----

stromatolites, planet , oxygen

heavy bombardment had what impacts

the impacts vaporized oceans and melted it's crust

the young sun was ---- than it is today

weaker

where are some of the oldest rocks found on earth? how old are these rocks?

west Greenland 3.7- 3.9 billion years old