BY4

Explain the reason for the lag phase during population growth

What is meant by the tem 'carrying capacity'?

Distinguish between density dependent and density independent factors

List three density dependant factors that limit the population growth

List the properties of an organism used for biological control of a pest

A parasitic wasp may be used to control whitefly populations in a glasshouse. State two reasons why it would be inappropriate to use both a chemical and biological control method at the same time

Explain why plants require nitrate

Give the term for the process of converting ammonium ions to nitrate ions

What stage in the nitrogen cycle is this:

Dead plants and animals are decomposed into ammonium ions

What is nitrogen fixation?

Give an example of free living bacteria

What is Rhizobium?

Which releases more energy, fat or carbohydrate?

What is the difference between an absorption spectrum and action spectrum?

Which pigment is found at the reaction centre?

What is the source of replacement electrons for photosystem 2?

State two differences between cyclic and non - cyclic photophosphorylation

Why is it essential to regenerate ribulose bisphosphate?

Name the three shapes of bacteria

What additional chemical is present in the cell wall of gram negative bacteria?

What colour would gram negative bacteria stain in the gram stain test?

Apart from oxygen, list three other requirements for microbial growth

Define a pathogen

What assumption is made when counting bacterial colonies?

By what process does one cell give rise to a colony?

State three advantages of using industrial fermenters

Why is ammonia included as one of the nutrients in fermentation?

Why is the cooling jacket essential to the process of fermentation?

Define a secondary metabolite

Name a cell type with a large number of mitochondria

Where do the following occur:

-Glycolysis
-Krebs cycle

Explain the role of oxygen in the electron transport chain