Outline
Describe the conditions of early Earth and outline that these conditions
may have led to the spontaneous generation of carbon compounds.
Explain why cells are the smallest units of self-sustaining life.
Outline some of the challenges of explaining the spontaneous origins of
cells.
Outline and evaluate the Miller–Urey experiment.
Outline how vesicles may have spontaneously formed by the coalescence
of fatty acids into spherical bilayers.
Explain the hypothesis that RNA was the first genetic material and catalyst
in the earliest cells.
Describe how it is likely that other life forms evolved, but were
outcompeted by a last universal common ancestor.
Outline approaches to estimate the time over which life has been evolving
on Earth.
Outline the evidence that supports the existence of a LUCA.
Explain why cells are the smallest units of self-sustaining life.
Outline some of the challenges of explaining the spontaneous origins of
cells.
Outline and evaluate the Miller–Urey experiment.
Outline how vesicles may have spontaneously formed by the coalescence
of fatty acids into spherical bilayers.
Explain the hypothesis that RNA was the first genetic material and catalyst
in the earliest cells.
What were the conditions of early earth?
Hardly any levels of oxygen because it had reacted with other compounds
(e.g. iron)
Methane concentrations were very high due to volcanic activity
Carbon dioxide concentrations were high due to emissions from volcanoes.
Temperatures were higher - greenhouse
Ozone layer barely existed because of the lack of O2 - Ub radiation higher
Surface temps probably ranged from 75 C to 95 C
Surface was covered with single global ocean, no land mass
The early Earth was subject to bombardment by comets and asteroids,
which brought water and other compounds to the planet.
, Methane and ammonia gases were released in these collisions and in the
many volcanic eruptions that were occurring. As a result, these two gases
formed the majority of the Earth’s early atmosphere, which also contained
water vapour (H2O) and higher concentrations of carbon dioxide (CO2).
Conditions would have created extreme weather events, including
electrical storms
How did the conditions of earth change?
The oxygen content of Earth’s atmosphere has considerably changed over
the last 4.5
billion of years. The concentrations was at zero, and has now stabilized at ca.
20%.
Because bacteria photosynthesises due to having chlorophyll adding
oxygen into the atmosphere
The bacteria reproduces fast so as time went on, it grew rapidly, adding
more oxygen.
Bacteria was the earliest life form.
Cells as the smallest units of self-sustaining life
A virus is very powerful pathogen and is not alive.
MR H GREN
Metabolism: process such as cellular respiration or photosynthesis which involve
the production or build-up of energy
Response/irritability: the ability to detect changes in the environment and to
respond accordingly
Homeostasis: the tendency towards a stable internal environment (e.g. temp,
pH)
Growth: a cell needs to grow to maximise its surface area (important to carry out
metabolic functions)
Reproduction: passing on genetic material to the offspring (sexually or asexually
e.g. by splitting)
Excretion: to get rid of unnecessary substances and waste products (e.g. CO2,
lactic acid)
Nutrition: to consume organic materials to produce energy
Can cells spontaneously become cells?
Describe the conditions of early Earth and outline that these conditions
may have led to the spontaneous generation of carbon compounds.
Explain why cells are the smallest units of self-sustaining life.
Outline some of the challenges of explaining the spontaneous origins of
cells.
Outline and evaluate the Miller–Urey experiment.
Outline how vesicles may have spontaneously formed by the coalescence
of fatty acids into spherical bilayers.
Explain the hypothesis that RNA was the first genetic material and catalyst
in the earliest cells.
Describe how it is likely that other life forms evolved, but were
outcompeted by a last universal common ancestor.
Outline approaches to estimate the time over which life has been evolving
on Earth.
Outline the evidence that supports the existence of a LUCA.
Explain why cells are the smallest units of self-sustaining life.
Outline some of the challenges of explaining the spontaneous origins of
cells.
Outline and evaluate the Miller–Urey experiment.
Outline how vesicles may have spontaneously formed by the coalescence
of fatty acids into spherical bilayers.
Explain the hypothesis that RNA was the first genetic material and catalyst
in the earliest cells.
What were the conditions of early earth?
Hardly any levels of oxygen because it had reacted with other compounds
(e.g. iron)
Methane concentrations were very high due to volcanic activity
Carbon dioxide concentrations were high due to emissions from volcanoes.
Temperatures were higher - greenhouse
Ozone layer barely existed because of the lack of O2 - Ub radiation higher
Surface temps probably ranged from 75 C to 95 C
Surface was covered with single global ocean, no land mass
The early Earth was subject to bombardment by comets and asteroids,
which brought water and other compounds to the planet.
, Methane and ammonia gases were released in these collisions and in the
many volcanic eruptions that were occurring. As a result, these two gases
formed the majority of the Earth’s early atmosphere, which also contained
water vapour (H2O) and higher concentrations of carbon dioxide (CO2).
Conditions would have created extreme weather events, including
electrical storms
How did the conditions of earth change?
The oxygen content of Earth’s atmosphere has considerably changed over
the last 4.5
billion of years. The concentrations was at zero, and has now stabilized at ca.
20%.
Because bacteria photosynthesises due to having chlorophyll adding
oxygen into the atmosphere
The bacteria reproduces fast so as time went on, it grew rapidly, adding
more oxygen.
Bacteria was the earliest life form.
Cells as the smallest units of self-sustaining life
A virus is very powerful pathogen and is not alive.
MR H GREN
Metabolism: process such as cellular respiration or photosynthesis which involve
the production or build-up of energy
Response/irritability: the ability to detect changes in the environment and to
respond accordingly
Homeostasis: the tendency towards a stable internal environment (e.g. temp,
pH)
Growth: a cell needs to grow to maximise its surface area (important to carry out
metabolic functions)
Reproduction: passing on genetic material to the offspring (sexually or asexually
e.g. by splitting)
Excretion: to get rid of unnecessary substances and waste products (e.g. CO2,
lactic acid)
Nutrition: to consume organic materials to produce energy
Can cells spontaneously become cells?
