populations in ecosystems

What decomposes plants in eutrification: sapribionts decompose plants aerobically in eurification

Why do plants die in eutrification: as they don’t have 02 to respire

allopatric speciation = geographical isolation

sympateric speciation = reproductive isolation ( though you can use this to describe allopatric as well)

process of succession- REMEMBER THE WORD SPECIES

1. (Colonisation by) pioneer species;

2. Pioneers change the environment/factors; e.g. forms soil/nutrients.

3. (Environment becomes) less hostile for other/new species

previous species out-competed.

4. Change/increase in diversity/biodiversity; Ignore increase in genetic diversity.

5. (To) climax community

use quadrant grid to count species

digesting proteins provides amino acids

digesting dna provides phosphates for ATP

succession is : change in community over time; either due to change environmental / abiotic factors / change is due to species present;

climax community is : able community / no further succession / final community;

interspecific competition for nutrients e.g nitrates or glucose resulting in reduced synthesis of protein and so less leaves produced

Why can energy transfer be less efficient

1. Energy lost between trophic feeding levels

2. Energy lost via respiration/excretion/faeces

What allele characteristics can cause once there is a selection pressures the allele frequence to rapidly increase: if the allele is dominant as is always expressed in phenotype

three reasons for low efficiency of energy transfer from secondary to tertiary consumers : not all food eaten/digested , heat loss from respiration, energy lost via excretion