Life Processes In Biosere

Question 1

Starting conditions

Answer 1

Hydrosere - water
Lithosere - Bare rock
Psamosere - sand

Question 2

How abiotic factors change during ecological succession

Answer 2

Temperature extremes - h - l
Water availability- l-h
Light levels - h- l
Nutrient availability- l -h
Rates of change- rapid to slow

Question 3

How biotic conditions change during ecological succession

Answer 3

Main pollination method: wind -> insect
Main seed dispersal: wind -> animal
Importance of inter species relations: l -> h
Biomass: l -> h
Biodiversity: l -> h

Question 4

Species richness

Species diversity

Answer 4

: no.of different species in an area.

: no. Different species in area and their relative abundance

Question 5

Why measure biodiversity?

Answer 5

Important to monitor environmental change, habitat Damage, and success of conservation

Question 6

Simpsons diversity index formula

Answer 6

D = N(N-1) / sum of n(n-1)
N = total no of organisms 
n = Total number of organisms of an individual specie

Question 7

Why rainforests have high biodiversity

Answer 7

Smaller range of climatic conditions
Structural complexity of vegetation equals more niches
One of the Oldest most stable ecosystems
Intense competition between species equals more specialisation equals more speciation
Hot and wet equals greater productivity

Question 8

Why species remain undiscovered

Answer 8

Inaccessible ecosystems / habitats
Similar appearance of different species
Similarities between males and females
Many plants only identified by the flower

Question 9

Population

Answer 9

= Starting population + births + immigrants- deaths - emmagrants

Question 10

Biotic potential

Environmental resistance

Answer 10

• The maximum possible rate of reproduction of a species under optimum conditions and limited resources
• The biotic and abiotic factors that prevent species or communities reaching the biotic potential i.e. factors that cause some to die.

Question 11

Density independent factors

Answer 11

These include factors where the population density has no affect on the chances of survival of an individual
Eg.
Drought, flood, volcano eruption

Question 12

Density dependent factors

Answer 12

Factors where chance of an individual surviving depend on the population density Of the species. Survival chances higher when population density low usually, and lower when the population density is high.
Eg
Food supplies
Disease

Question 13

Carrying capacity

Answer 13

Greatest population at an area can support indefinitely without damaging or over – exploiting the environment
Mortality rate in a population changes if population size above or below caring capacity, so the population size changes back to the car

Question 14

Artificial population control

Answer 14

Colin may be required to enable A species to survive when natural mechanisms no longer regulate the population

Question 15

Artificial control of population needed when

Answer 15

• breeding rate of endangered species low so captive breeding and release program
• non-indigenous species is introduced which reduces the population of indigenous species because of its predator competition or pathogen
• Indigenous predator removed

Question 16

Biome

Answer 16

Large geographical region with specific climatic conditions within which a characteristic community of species lives

Question 17

Ecosystem

Answer 17

Combination of the biotic and abiotic features of an area. It includes the community of species, they’re into relations with each other and the relationship with the physical environment such as energy, water and nutrients.

Question 18

Habitat

Answer 18

Area or location where a species or community of species lives

Question 19

Ecological niche

Answer 19

Ecological niche of a species is the role it plays in its habitat