6. Geobiology

Question 1

What is geobiology?

Answer 1

The study of how physical, chemical and biological processes influence one another in natural systems.

Question 2

What are the four components of the Earth system?

Answer 2

The geosphere, atmosphere, hydrosphere (+/- crysophere) and the biosphere.

Question 3

What is the biosphere?

Answer 3

The sum of all living things and the environment in which they exist.

Question 4

What are the non-living (abiotic) components of the biosphere?

Answer 4

Carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P), sulphur (S).

Question 5

What are the taxonomic ranks of the living organisms (biota) in the biosphere?

Answer 5

Domain, kingdom, phylum, class, order, family, genus, species.

Question 6

What is metabolism?

Answer 6

The chemical processes which occur within a living thing necessary for maintaining life

Question 7

What is oxidation?

Answer 7

The loss of electrons or increase in the oxidation state of a chemical/atoms within it

Question 8

What is reduction?

Answer 8

The gain of electrons or decrease in the oxidation state of a chemical/atoms within it

Question 9

What is a redox reaction?

Answer 9

A reaction in which one molecule is reduced and another is oxidised; one molecule acts as an “electron donor” for the other.

Question 10

What is carbon fixation?

Answer 10

The process in which living organisms convert inorganic carbon into organic matter; CO2 is biochemically reduced.

Question 11

What is primary production?

Answer 11

Building organic matter through carbon fixation.

Question 12

How is energy classified?

Answer 12

There are two main energy sources. Phototrophy: energy source is sunlight.
Chemotrophy: energy source is chemicals.

Question 13

What are the two metabolic classifications?

Answer 13

Autotrophs and heterotrophs.

Question 14

What are autotrophs?

Answer 14

Primaryproducers: build organic matter by fixing carbon, providing most of the organic material in the bioshphere.

Question 15

What are heterotrophs?

Answer 15

Cannot fix carbon to form their own organic carbon, must consume organic material.

Question 16

What is oxygenic photoautotrophy?

Answer 16

H2O is used as the electron donor to produce oxygen as the waste product. e.g. photosynthesis

Question 17

What is anoxygenic photoautotrophy?

Answer 17

Doesn’t use H2O but some other electron doner e.g. photoferrotrophy in which iron is the e- donor

Question 18

What is chemoautotrophy?

Answer 18

Obtains energy by using reactions between naturally occuring chemicals. Most are extremophiles.

Question 19

What is the energy flow in an ecosystem like?

Answer 19

Light energy is used by primary producers to create organic matter. This organic matter is consumed by primary consumers, then secondary consumers then tertiary consumers etc. The total biomass decreases with each rung.

Question 20

How do we measure primary productivity?

Answer 20

1. Gross Primary Production (GPP): measure the biomass produced by an ecosystem
2. Net Primary Productivity (NPP): Total rate at which biomass accumulates i.e. GPP minus rate of respiration.

Question 21

What six elements are essential for life?

Answer 21

Carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P) and sulphur (S).
Organic molecules are those which contain carbon - all life on Earth is carbon based.