Topic 4 - Biodiversity And Natural Resources Flashcards
What is the definition of species?
A group of organisms with similar morphology, physiology and behaviour that can interbreed to produce fertile offspring that are reproductively isolated from other species.
What are the definitions of habitat and environment?
The place where an organism lives and any physical factor that affects an organism.
What are the definitions of population and community?
A group of organisms of the same species occupying a particular space at a particular time that can interbreed and produce fertile offspring.
All of the populations of species living and interacting in one area.
What is the definition of biodiversity and endemic species?
The variety of species that belong to every different group of organisms living in all the habitats on the planet.
A species only found in one place.
What does competition and fitness mean?
The interaction of individuals competing for a common resource which is in limited supply.
The extent to which an organism is well adapted to it’s environment.
What are the 2 types of competition?
- Interspecific = between 2 different species
- Intraspecific = within the same species
Why do we need to categorise organisms?
Communication, conservation and to categorise habitats.
How can we determine if 2 organisms are different species?
- DNA barcoding
- Look at phenotypes
- Can they produce fertile offspring
What is essential for species in a habitat?
- Place to live
- Energy
- Raw materials
- A mate
What are the 8 threats to species?
- Habitat destruction = removal of habitats
- Habitat degradation = reduction in quality of habitats
- Habitat fragmentation = breaking habitats into smaller pieces
- Overexploitation = excessively using a resource
- Land use change = human activities changing the natural landscape
- Climate change = change in global or regional climate patterns
- Pollution = presence of harmful chemicals in the environment
- Invasive species = non-native organisms that can out compete native species
Why is biodiversity beneficial?
Variation, genetic diversity which allows the population to adapt to changing conditions and the more genotypes the more genetically diverse the population is.
What are 6 sources of genetic variation?
- Random mutations = happens during meiosis by:
- Independent assortment
- Crossing over
- Gene point mutations = alterations of DNA base sequences
- Chromosome mutations = sometimes sections of chromosomes can be rearranged during meiosis
- Mate selection
Draw the genetic mutation tree
Genotype—> Mutation (gene point or chromosome)—-> Altered genotype—-> Prepared for sexual reproduction (crossing over or independent assortment) —->Gamete—-> Fertilisation (random fertilisation and mate selection) —-> Individual with new genotype—> Expression of genotype = phenotype
What are biodiversity hotspots and what are they defined by?
Regions of particularly high biodiversity defined by having 1500+ endemic vascular plant species and being irreplaceable.
What does the biodiversity index take into account and what is the equation?
Takes into account species richness and evenness so we get a more comprehensive picture.
DI= N(N-1)
Sum of n(n-1)
N= total number of individuals collected, n= number of individuals of a species
What does species richness and evenness mean?
Richness gives us the count and evenness tells us the relative abundance of population size of each species.
What does the heterozygosity index measure and what is the equation?
Measures the percentage of genes in heterozygous form which helps conservationist biologists determine where to locate their resources.
H=. Number of heterozygotes
Total population
What is the hardy Weinberg equation used for and what is it?
Used to see if there is a change in allele frequency over time which evidences natural selection. Scientists can observe the phenotypes of individuals and use them to find frequencies of alleles of the population.
P+Q=1
P2 + 2Pq +q2 = 1
P= dominant frequency
Q= recessive frequency
P2= AA, 2Pq= Aa, q2= aa
What is a niche?
The way an organism exploits its environment
What are the other 3 types of niche and explanations?
- Fundamental niche= the total area containing environmental conditions that an organism could theoretically tolerate.
- Preferred niche= area within the fundamental niche where conditions are ideal.
- Realised niche= part of the fundamental niche where an organism is actually found.
What happens when 2 species occupy the same niche?
They will be in direct competition so the better adapted organism will outcompete the other and exclude it from the habitat. This is called competitive exclusion.
What can 2 species sharing the same niche do to avoid competition?
Resource partitioning where species alter their use of the niche to avoid competition.
Definition of an adaptation?
Characteristics that allow a species to be better suited to their environment.
What is the process of adapting?
The process of change by which an organism or species becomes better suited to their environment.
What are the 3 types of adaptations?
Behavioural, physiological and anatomical
What is a behavioural adaptation and what is an example?
An action of an organism that helps them to better survive and reproduce.
E.g pregnant polar bears undergo modified hibernation
What is a physiological adaptation and example?
Features of the inner workings of organisms that help them to survive or reproduce.
E.g digestive modifications/ process body fat to access metabolic water.
What is an anatomical adaptation and example?
Structures we can see when observing or dissecting an organism.
E.g having 2 layers of fur
Definition of natural selection and struggle for existence?
- The mechanism by which species change over time
- Striving for survival in a competitive habitat.
Definition of survival of the fittest?
Differential survival of individuals depending on how well they are adapted to their environment.
