AS Conditions for Life on Earth Flashcards
Abiotic factors
Physical factors such as light, temperature and water.
Acidophile
An organism that thrives under acidic conditions. Many acidophiles are bacteria or archaea.
Aerobic process
A process that takes place in the presence of oxygen.
Anaerobic process
A process that takes place in the absence of oxygen.
Archaea
Microorganisms similar to bacteria, including the first life-forms to develop on Earth. Archaea are the only organisms that produce methane from the decomposition of organic matter.
Magnetosphere (of Earth)
The magnetic field around Earth which deflects charged particles travelling from the Sun.
Photoautotroph
An organism that produces high-energy food substances using sunlight in photosynthesis.
Mass of Earth
Earth’s mass is responsible for gravity. Gravity enables Earth to hold an atmosphere which contains many important gases.
Distance from the sun
Earth’s distance from the sun directly influences Earth’s temperature, making it suitable for life. The temperature also allows for liquid water.
Rotation of Earth
The rotation of the Earth allows for a 24 hour day. This reduces extremes of temperature.
Tilt on Earth’s axis
The earth’s tilt on its axis causes the Earth to tilt either towards or away from the Sun at different times of year. This produces seasonal changes.
Properties and importance of liquid water
Universal solvent, Transport of nutrients, high specific heat capacity, anomalous expansion (upon freezing)
Gases in Earth’s early atmosphere
Ammonia, Hydrogen sulphide, Methane, Carbon Dioxide, no free oxygen
Gases in Earth’s atmosphere that allowed complex life to develop
Carbon Dioxide, Nitrogen, Oxygen
Importance of Nitrogen
essential for the production of amino acids, proteins, DNA and RNA
