topic 4 - biodiversity and natural resources Flashcards
4.1 know that over time the variety of life has become extensive but is now being threatened by human activity.
variety has become extensive but is now being threatened by human activity such as deforestation.
as human population increases, the reliance on resources also increases - it destroys the habitat and negatively affects the species living in it.
4.2 i understand the terms biodiversity and endemism
biodiversity - the variety of living organisms in an area, it includes both genetic and species diversity
endemism - when a species is unique to a different location
(large number of species evolve from that area)
4 different ways we can measure biodiversity and define them
- species diversity:
the number of different species in an area and the abundance of them - species richness:
the number of different species in a particular place at a particular time - genetic diversity:
the variation of alleles in a gene pool of a species - ecosystem diversity:
the variety of alleles in an area
^ results in high species diversities
4.2 ii - (PAR T A) know how biodiversity can be measured within a habitat using species richness and within a species using genetic diversity by calculating the heterozygosity index
species richness: the number of different species in a habitat
species evenness: abundance of each individual species
4.2 ii) (PART B) Know how biodiversity can be measured within a species using genetic diversity by calculating the heterozygosity index
- what does a high & low heterozygosity index suggest?
genetic diversity -
the variation of alleles in a gene pool of a species
heterozygosity index - looks at the genes in a population which are heretozygous (Bb,bB)
(number of heterozygotes) ÷ (total number of individuals in the population
^ populations with more heterozygote individuals will have a greater range of alleles (dominant/recessive)
high = larger genetic diversity = more chance of survival
low =have a lot of individual gene loci with 1 allele only + lower genetic diversity
why do we need genetic biodiversity? (3)
- allows evolution
- allows longer term survival of a species
- preservation of alleles in a population
why does genetic variation occur + why do alleles change?
- alleles change as a result of mutations, fluctuations and meiosis
it doesn’t usually affect the phenotype
detrimental effect:
natural selection removes the alleles from the gene pool
beneficial effect:
will be selected for the environment + increase in frequency
4.2 iii) understand how biodiversity can be compared in different habitats using a formula to calculate an index of diversity
simpson biodiversity index
D = N(N-1) / n(n-1)
D = diversity index (probability of 2 randomly selected individuals belonging to the same species
N = total number of organisms
n = total number of organisms of each individual species
how can we experimentally measure biodiversity? (5)
- quadrats - count the number of species in a known area (species richness)
- pooters ( straw to suck up insects)
- pitfall traps to collect nocturnal insects
- swap nets - butterflies
- capture,recapture method - capture animals without harming them + marking them, then catch them again to see which are marked
what 2 things do we need to assess biodiversity at species levels?
1.species richness - the number of species in one area
2. relative species abundance/species evenness - the number of each individual species in one area
why do we need to protect biodiversity (5)
- ensures a stable atmosphere of gases and is a source of O2
- foundation of human resources and welfare
- needed for long term sustainability + mitigation of climate change
- essential for the security of food
- large genetic diversity = less impact from other species
define biodiversity hotspots and an example + why conservation efforts are focused here
give 3 reasons why these hotspots exist
areas with particular high levels of plant biodiversity
- usually have a high number of endemic species
these areas are rich in resources - wood oils + minerals
LEADS to DESTRUCTION and DECLINING BIODIVERSITY
eg - wet tropics due to high species richness + endemism
- a very stable ecosystem - allows complex relationships to develop between species
- high levels of productivity ( photosynthesis) supports niches
- organisms grow and reproduce rapidity increasing the likelihood of mutations which leads to adaptions and allows more niches to be exploited (used)
4.3 understand the concept of a niche
- what happens when 2 species share the same niche
role/organism of a species within it’s habitat consisting of both it’s biotic (what it eats) and abiotic (time of day its active) interactions
- they will compete with each other and the better adapted to the environment will exclude the other species from its habitat (natural selection)
^ show better adaptions to niche = higher chance of survival + passing on gene
4.3 be able to discuss examples of adaptation of organisms to their environment
- behavioural - acts/reactions that an organism produces as a response to a particular cirumstance (the way it interacts with the environment) + improves chances of survival
eg - hibernation, mating calls - physiologcial - function = processes which have physical and chemical qualities)
eg - temp control, reproductive strategies, digestion + chemical signalling - anatomical - bodily structure of an organism
eg - oily fur, camouflage
define
1. species
2. habitat
3. population
4. community
5. niche
- a group of organisms with similar morphology, physiology and behaviour, which can interbreed to produce fertile offspring and which are re productively isolated (in place, time or behaviour) from other species.
- the place where an organism lives 3. a group of interbreeding individuals of the same species found in an area
- the various populations in an area make up a community 5. the way an organism exploits (uses) its environment
