Biodiversity Flashcards
Definition of Biodiversity
Number of species and number of individuals of each of the species within any one community
Definition of Species Richness
Number of different species in a community
Definition of Community
All the individuals of all the species living together in the same area at the same time
Definition of Species
Group of similar organisms with the same genes that reproduce to produce fertile offspring
Definition of Genetic Diversity
Difference in DNA/base sequence/alleles/genes
Definition of Niche
An organisms role in the community
It describes how it interacts with other species + how it responds to the environment
Definition of Habitat
A place where an organism normally lives within an ecosystem
Definition of Population
Number of specific species
How to calculate diversity index?
What information is required to calculate this?
Number of species
Number of individuals in each species
The number of species present is one way to measure biodiversity.
Explain why an index of biodiversity may be a more useful measure of biodiversity?
Also measures number of individuals of each species
Give 2 advantages of using an index of biodiversity rather than an indicator species?
- Don’t need to identify each species
- Index considers the number of organisms of each species
Suggest economic arguments for maintaining biodiversity? (4)
- Tourism
- Agriculture
- Saving local forest communities
- Medical uses
A forest was cleared to make more land available for agriculture.
After the forest was cleared the species diversity of insects in the area decreased. Explain why? (4)
- Decrease in variety of plants
- Fewer habitats/niches
- Decrease in variety of food/food sources
- Aspect of clearing forest (killing insects) e.g. machinery/pesticides
Farmers clear tropical forest + grow crops instead.
Explain how this causes the diversity of insects in the area to decrease? (5)
- Lower diversity of plant
- Fewer sources of food
- Fewer habitats/niches
- Fewer herbivores so few carnivores
- Aspect of agriculture (killing insects)
Name the Hierarchy
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is the binomial naming system?
Genus Name, species name
—–> Capital Letter
Definition of Taxon
Group of similar organisms
Definition of Hierarchy
Groups contained within larger groups, which have NO overlap + organisms have only ONE taxon
What are the groupings on domain?
- Bacteria
- Archaea (group of prokaryotes)
- Eukarya
How many kingdoms does the eukarya domain divide into? Names?
4 kingdoms - Protist, Fungi, Plant, Animal
Definition of Phylogenic group?
Grouped according to evolutionary links with common ancestry
Why do organisms display courtship behaviour?
To attract a mate of the same species and opposite sex to ensure reproductive success
Give 5 ways in which courtship increases the probability of successful mating?
- Attracts same species
- Attracts opposite sex
- Indication of sexual maturity/fertility
- Stimulates release of gametes
- Form pair bond
In classification, comparing the base sequences of a gene provides more information than comparing the amino acid sequence for which the gene codes. Explain why?
- Reference to base triplet/ more bases than amino acids
- Introns/non-coding DNA
- Same amino acids may be coded/DNA code is degenerate
Comparing the base sequence of genes provides more evolutionary information than comparing the structure of proteins. Explain why?
- Reference to base triplet/ more bases than amino acids
- Introns/non-coding DNA
- Same amino acids may be coded/DNA code is degenerate
Give 2 ways doctors could use base sequences to compare different types of HPV?
- Compare DNA base sequence
- Compare mRNA base sequence
- Look for mutations
Describe how comparisons of biological molecules in 2 species could be used to find out if they are closely related? (4)
- Compare DNA
- Compare sequence of bases/nucleotides
- Compare sequence of amino acids/primary structure
- Compare same/named protein
Definition of:
- Interspecific
- Intraspecific
- Competition for resources between organisms of different species e.g. food sources
- Competition for resources between individuals of the same species e.g. mates, courtship
What is a biotic factor?
Living factors (competition, predation, disease)
What is an abiotic factor?
Non-living factors (temperature, light intensity, soil/water pH)
What is primary succession?
Occurs in environment when introduction of new plants/animals into area aren’t supported by community
What is secondary succession?
Occurs after forest fire or clearance of agricultural land so vegetative organs may remain viable so influx in animals/plants
What is deflected succession?
Occurs when climax community is prevented from establishing e.g. practices by humans
Describe the process of succession (6)
Explain how succession results in a wide variety of fish living on coral reefs (2)
- Increase in variety of species/plants/animals OR Increase in number of species/populations; OR Increase in species richness / biodiversity
- Provides more/different habitats/niches OR Provides greater variety/types of food OR becomes less hostile
Describe random sampling
[estimation of population density]
[5]
- Use a grid to split area into squares/sections
- Method of obtaining random coordinates e.g. random number generator
- Count number/frequency of plants in a quadrat
- Large sample (20+ quadrats) AND Calculate mean/average number (per quadrat/section);
- Valid method of calculating total number of ……… e.g. mean number of plants per quadrat multiplied by number of quadrats in area
Describe systematic sampling [3]
- Transect/lay line/tape measure
- Place quadrats at regular intervals along the line
- Count plants/percentage cover/abundance scale (in quadrats) OR Count plants and record where they touch line/transect
Which type of sampling would you choose?
On a beach
RANDOM
Which type of sampling would you choose?
Along a beach
SYSTEMATIC
Which type of sampling would you choose?
In a wooded habitat
RANDOM
Which type of sampling would you choose?
On a coral reef
RANDOM
Which type of sampling would you choose?
Investigate how the distribution of species changes across a sandune away from the sea
SYSTEMATIC
Describe how you would determine the mean percentage cover for beach grass on a sand dune. [3]
- Method of randomly determining position (of quadrats) e.g. random numbers table/generator
- Large number/sample of quadrats (min 20)
- Divide total percentage by number of quadrats
Describe the mark, release, recapture technique (4)
- Capture sample, mark and release;
- Appropriate method of marking suggested + doesn’t harm
- Take second sample and count marked organisms;
- Calculate population =
(No in sample1 × No in sample2) divided by Number marked (recaptured) in sample 2
Suggest why the mark-release-recapture method can produce unreliable results in very large lakes [2]
- Less chance of recapturing fish OR Unlikely fish distribute randomly/evenly;
- Fish may remain in one area OR fish may congregate
Describe how you would determine how many quadrats to use when investigating a habitat. (3)
- Calculate running mean
- Enough to carry out a statistical test
- A large number to make sure results are reliable + representative
What is meant by carrying capacity?
Maximum number of individuals of each species an ecosystem can support
Suggest two reasons for conserving rainforests?
- Conserve/protect species/plants/animals/organisms OR for (bio)diversity
- Conserve/protect habitats/niches OR Provides/many habitats/niches; or conserve land for indigenous communities;
- Reduces climate change;
- Source of medicines/drugs/wood;
Reduces erosion/eutrophication; - Tourism;
Give 2 features of a climax community?
- Stable population
- Abiotic factors are constant
