EES - Development of the Biosphere (MOD5T1)

5.1.1 investigate evidence for the origin of organic molecules on Earth, including: - Urey & Miller's experiments - Communities around Black Smokers - Meteorites/panspermia 5.1.2 investigate the evidence for the development of photosynthetic life, including cyanobacteria and stromatolites 5.1.3 evaluate the evidence for the origin of multicellular life and resulting changes to ecosystems, for example, the Ediacaran and Cambrian fauna

Organic molecules

contain carbon bounded to hydrogen

Inorganic molecules

does not contain carbon bounded to hydrogen

Anoxic

no oxygen

Oxic

with oxygen

Black Smokers

A hydrothermal vent on the ocean floor that emits geothermally heated water with sulfide minerals

Chemosynthesis

process in using inorganic molecules to produce food and energy in deep sub-surface

Extremophiles

live in extreme environments

Primitive atmosphere

water vapour, carbon dioxide, hydrogen, methane, ammonia, and nitrogen

Archaea

prokaryotic unicellular microorganisms

Panspermia theory

suggests that life did not originate on Earth but arrived in the form of bacterial spores or viruses from an extraterrestrial source

Amino acids

building blocks of proteins

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes (multicellular)

Prokaryotic cells

do not have a nucleus or other membrane-bound organelles (unicellular)

Abiotic precursors

non-living components of an ecosystem that can create organic molecules, or complex chemical structures, without life

Heterotrophic cells

cannot produce its own organic molecules; relies on other sources

Autotrophic cells

Are able to convert inorganic molecules to organic molecules - PRODUCER i.e plants, cyanobacteria

Photosynthesis

Conversion of light energy from the sun into chemical energy.

6CO2 + 6H2O -> C6H12O6 + 6O2 + ATP

Cyanobacteria

Prokaryotic cells capable of photosynthesis

Banded Iron Formations (BIFs)

Sedimentary rocks that have alternating layers of iron-rich minerals and silica-rich minerals (i.e. chert, quartz).

Endosymbiosis theory

The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another.

Microfossils

microscopic fossils

Stromatolites

Rocky deposit formed by communities of cyanobacteria in microbial mats

Great Oxygenation Event (GOE)

The period in Earth's history during which oxygen built up relatively rapidly in the planet's atmosphere (due to the increase population of cyanobacteria)

Colonial theory

Proposes that multicellular organisms evolved from colonies of single-celled organisms

Cambrian explosion

An event in the Cambrian period suggesting the sudden and rapid evolution of new organisms

Desiccation

drying out

Arthropods

Invertebrate animals with exoskeletons, segmented bodies, and jointed limbs

Tetrapods

Four-limbed vertebrates that evolved from fish, including amphibians, reptiles, birds, and mammals.

Sessile fauna

Organisms that are fixed in one place and do not move freely