4b Flashcards
Biotic conditions
Plant and animal communities
Changes in abiotic conditions
Water availability
Primary succession
Happens on land that has been newly formed or exposed. (Where a volcano has erupted to form new rock surfaces)
Secondary succession
Happens on land that’s been cleared of all plants but where soil remains (after a forest fire)
Climax community
Final stage of succession - the ecosystem is supporting the largest and most complex community of plants and animals it can. It’s at a steady state and won’t change much more!
Succession
Is the process if ecosystem change over time
Primary succession - abiotic conditions are hostile means??
There’s no soul to retain water - pioneer plants are specialised to cope with long roots ect
Primary succession - abiotic conditions are less hostile means??
The basic soil is deeper and helps to retain water and structure for new organisms. Soil = deeper and richer in minerals !
What is a plagioclimax?
When human activity prevents succession, stopping a climax community from developing. When succession is stopped artificially!
Examples of human activity that cause plagioclimax ?
Animals grazing on land
Managed fires are lit.
Species ?
A species is a group of similar organisms that can reproduce to give fertile offspring
Population ?
A population is a group if organisms of the same species living in a particular area.
The gene pool?
The gene pool is the complete range of alleles present in a population
Hardy-Weinberg principle
Predicts that the frequency of alleles in a population won’t change from one generation to the next.
Conditions needed for the Hardy Weinberg principle to apply ??
Large population where there's.... NO immigration NO emigration NO mutations NO natural selection
There also needs to be random mating
(All possible genotypes can breed with all others)
How does ATP store energy?
Bonds between phosphate groups are unstable and have a low activation energy - meaning they are easily broken and they release a lot of energy!
What do organisms need energy for?
Metabolism Movement Active transport Maintenance, repair and division Production if substances Maintenance of body temperature
The synthesis of ATP from ADP and Pi occurs in three ways??
Photophosphorylation
Oxidative phosphorylation
Substrate-level phosphorylation
What is photophosphorlyation??
It takes place in chlorophyll containing plant cells during photosynthesis
What is oxidative phosphorylation?
Occurs in mitochondria of plant and animal cells during the electron transport chain
What is substrate-level phosphorylation??
It occurs in plant and animal cells when phosphate groups are transferred from phosphate groups to ADP to make ATP.
E.G. In the formation of pyruvate at the end of glycolysis
ATP is an ___________ energy source for the cell?
Immediate energy source.
Cells store only a few seconds supply
Why is ATP a better immediate energy source than glucose?? (2 points)
Energy from ATP is released in smaller more manageable quantities rather than glucose releasing the opposite.
The hydrolysis of ATP is a single reaction. The breakdown of glucose is a series of reactions and energy release takes longer
How does ATP provide energy for metabolic processes??
ATP provides energy to build up macromolecules from their basic units…
Polysaccharide synthesis from monosaccharides
Polypeptide synthesis from amino acids
DNA/RNA synthesis from nucleotides
What is the hydrolysis of ATP?
Bonds between the phosphates in ATP are unstable and have a low Ea and are easily broken. Aka hydrolysis (addition f water)
