Life On Earth Flashcards
What happens in energy transfers
How much energy is used for growth ?
The majority is lost as best , movement and undigested materials
Only a small quantity used for growth
What do fertilisers provide
Nitrates
What do nitrates do
Increase crop yield
What happens when nitrates are dissolved in soil water
Absorbed into plants
What are nitrates used for to produce
Used to produce amino acids which are synthesised into plant proteins
Why do animals consume plants or other animals (hint- ……synthesis)
To obtain amino acids for protein synthesis
Fertilisers do what when they go into fresh water
Add extra unwanted nitrates
Cause algal blooms - increase algal population
What do algal blooms do
Reduce light levels. Killing aquatic plants
What do the dead plants become food for
Bacteria which means the population will increase
What does he bacteria use up a lot of and what does it do for other organisms
Oxygen and this reduces availability for other organisms
What is the build up of toxic substances called
Bioaccumulation
What is a mutations
A random change to genetic material
How do mutations appear and what are they a new source of
Spontaneous and source of new alleles
What can new alleles have an affect on
Animals becoming better adapted to their environment
Variation within a populations makes it possible for what
To evolve over time in response to changing environmental conditions
An adaptation is …
An inhertited characteristic that meld an organism well suited to survive in its environment/niche
Natural selections occurs when
There are selection pressures
Speciation occurs when
A population becomes isolated by an isolation barrier
Light reaction
Light energy from sun - trapped by chlorophyll in chloroplasts - converted into chemical energy - used to generate ATP
Water is split to produce hydrogen and oxygen
Oxygen diffuses from the cell
Carbon fixation
Uses hydrogen and ATP with carbon dioxide to produce sugar
Fates of sugar - the chemical energy in sugar is available for respiration or the sugar can be converted into other substances :
Starch ( storage ) and cellulose (structural )
Limiting factors for photosynthesis reactions
Carbon dioxide concentration , mught intensity and temperature and their impact on photosynthesis and plant growth
