Origins Of Life Flashcards
Life on earth thought to have begun _ years ago
3.7 billion
Life began only _ years after our planet formed
A few hundred million
Process of life forming from non-living material know as
Abiogenesis
_ was poisonous to early forms of life
Oxygen
First major theory of origins of life was _ theory
Primordial soup
Primordial soup theory proposed that _ contained raw materials for life
Earth’s early oceans
Complex structures such as _ were cooked from oceans raw materials over long period of long chemical reactions (2)
DNA
Proteins
Another theory is the _ theory
Hydrothermal vent
Life first arose from _
(Hydrothermal vent theory)
Hydrothermal vents
In hydrothermal vents _ well up from inside Earth’s crust (2)
Heat
Minerals
_ created right conditions for creation of complex substances (2)
Heat
Pressure
Heat and pressure heat and pressure can combine to form
Protocells
The rich supply of _ may have powered chemical reactions in the protocells (hydrothermal vents)(2)
Chemicals
Mineral catalysts
- Earth’s early atmosphere was full of simple _ released by volcanic activity (2)
Carbón-rich compounds
Nitrogen-rich compounds
- The carbon/nitrogen-rich compounds dissolved into _
Water in the oceans
- Triggers such as _ caused compounds to join together to form simple organic substances (v)
Volcanic eruptions
(Sugars, amino acids)
- Triggers such as _ caused compounds to join together to form simple organic substances (s)
Sunlight
(Sugars, amino acids)
- Triggers such as _ caused compounds to join together to form simple organic substances (u)
Ultraviolet rays
(Sugars, amino acids)
- Simple organic molecules formed _
Polymers
Polymers are
Long molecules built up from chains of small units
- Primitive proteins were created from polymers such as (3)
Proteins (peptides)
Carbohydrates (sugars)
Lipids (fats)
4.in some organic molecules, one end _ other end _
Repels water
Attracted to water
- Km water, such molecules may have clustered into membranes with
Water-loving ends as outer layer
- Some membranes formed sacs called
Vesicles
- (Replicators) it is thought that some polymers could _
Autocatalyze
- (Replicators) autocatalyze means one molecule acted as a template to
Build a second molecule
- (Replicators) these replicating chemicals competed for raw materials and
Evolved by natural selection
- (Replicators) evolved by natural selection until _ evolved
RNA
- (Early cells) the first protocells may have been simply a _
Replicating polymer enclosed in a membranous vesicle
- (Early cells) enclosed replicating polymer able to store _ for making copies or itself
Raw materials
- (Early cells) copies of itself and chemicals involved in chains of reactions the earliest _
Form of metabolism