Biology Module 4 Flashcards
Biodiversity and disease
What is Biodiversity defined as?
Biodiversity refers to the measure of the variation found in the living world.
What are the 3 types of diversity?
-Species diversity, a measure of the number of species present in a habitat
-Habitat diversity, a measure of the number of different habitats for different species in an area
-Genetic diversity, a measure of the variation in a breeding pool of a species
What are the 2 different types recording data using a transect line?
- Line transect - Only recording species that touch the line
- Belt transect - Using a quadrat at regular intervals along the line to provide a greater volume of results
What is species richness?
It refers to the number of different species found in a habitat. This is measured by taking random samples of a habitat and counting the number of species found.
Higher number of species = Higher species richness
What is species evenness?
It refers to the relative abundance of individual species in a habitat. This is measured by taking random samples of a habitat and counting the population of each different species collected.
More evenly balanced population = Higher species evenness
Eg, field full of 20 poppies, and 1 of 30 other types of plants = High species richness, low species evenness as poppies have the highest population
What is Simpsons index?
A method of measuring the diversity of a habitat by taking into account both the species richness and species evenness.
D=1-[∑(n/N)2]
D=diversity of habitat
n=total number of organisms of a particular species of % cover
N=total number of organisms in habitat
*observed value D will always be between 1 and 0
What are alleles, locus and genes?
-Alleles are are a version of gene
-Locus (plural Loci) is the position of a gene on a chromosome
-Genes are a section of DNA on a chromosome that codes for the aa in a polypeptide chain
What are the three methods for working out the genetic diversity of a habitat?
- Observing and counting the phenotypes present
- Calculating the number of loci in one individual that are heterozygous (not a good measure)
- Calculating the percentage of loci in the population that have more than one allele (polymorphic gene loci)
What is polymorphic gene loci, and what is the related equation?
Some loci have more than two alleles, which helps increase the genetic diversity of a population as there is a greater variety of alleles that may appear in an organisms genotype.
Proportion of polymorphic gene loci=Number of polymorphic gene loci/Total number of loci x100
What is genetic erosion?
The selection of specific breeds of domesticated plants or animals may cause other breeds to die out due to the lack of genetic diversity
What are the 5 main factors affecting biodiversity?
-Habitat destruction
-Overexploitation
-Human population growth/actions
-Agriculture
-Climate change
How does Habitat destruction affect biodiversity?
Habitat destruction can appear in 2 forms:
-Habitat loss, plants and animals completely lose their habitats for food/agriculture, housing, waste disposal, etc
-Habitat fragmentation, habitats are divided into small areas. Populations in these habitat fragments are more likely to suffer from inbreeding or local extinction
-Deforestation is most damaging type of habitat destruction as forest habitats usually contain very high levels of biodiversity
-Coral reefs are also being destroyed (dynamite fishing damages coral beds)
-Sea beds are being destroyed (fishing practises such as trawling damages this habitat)
How does Overexploitation affect biodiversity?
-Resources are being used up faster than they can be replenished, eg, deforestation as trees are being removed faster than they can be replanted/regrow
-Fish stocks also overexploited, causing effects for their larger habitat
How does agriculture affect biodiversity?
-A decrease in natural vegetation and habitat size reduction, paired with the increase in monocultures decreases the genetic diversity of a species
-Monocultures also support lower levels of biodiversity, eg, Borneo and palm oil
-Selective breeding leads to genetic erosion and a reduce in genetic diversity
-Fields made bigger to accommodate large machinery by removing hedgerows, an important habitat for small organisms
-Fertilisers can leach into waterways, leading to eutrophication and the death of aquatic organisms
-Pesticides can kill non-target species, like bees, important pollinators
-Filling in ponds/draining wetlands can disrupt migrations
How does Human population affect biodiversity?
-As it increases so does the demand for food, water and consumer goods
-Leads to habitats being converted and destroyed for agriculture
-Pollution occurs, eg, SO2 causing acid rain
-More finite resources are overexploited
How does Climate change affect biodiversity?
-Due to reduced genetic diversity (caused by monocultures, genetic erosion, etc) some species are less able to adapt to changing conditions so may die out, reducing biodiversity
-This can also occur due to fragmented habitat
-Changing conditions may affect natural migrations of animals due to global warming, so may cause them to die out and reduce biodiversity
-Global warming is also causing organisms to migrate towards the poles or to higher ground
-This can cause species to die out due to inability to live in those new conditions, due to being outcompeted/outcompeting others, or a new disease, all of which reduce biodiversity
What is Extinction and how high are the rates of extinction at this moment in time?
-Extinction occurs when the last member of a species dies, causing the species to no longer exist
-Over 800 recorded extinctions since 1500, and 20% species could be extinct by 2030, 50% by 2100
-Current rate of extinction 100-1000x higher than ‘normal’ background rate
-In a mass-extinction event at least 2x as fast as previous mass-extinction events
What is the Convention on Biological Diversity (CBD)?
-Signed at earth summit in Rio in 1992
-Countries that signed agreed to implement conservation strategies and instigate further international co-operation
3 main goals:
1. Conservation of biological diversity
2. Sustainable use of resources
3. Fair sharing of benefits arising from genetic resources
What is the Convention on International Trade of Endangered Species of wild flora and fauna (CITES)?
-Aims to control endangered species trade
-Categorizes species into 3 appendices
1. Species that are endangered and face threat of extinction, eg, red panda
2. Species not currently endangered but will if trade not regulated, eg, Venus flytrap
3. Species included via a request from a country regulating trade of a species to prevent its overexploitation
Different regulations for each appendix:
1. All trade in a species and its products is banned
2. Permits required from associated countries
3. Permit required, though more easily obtained
-Species continuously added and re-evaluated
-Concern of CITES efficacy as when species is endangered, price rises and so therefore does incentive to break the law
What is the Countryside Stewardship Scheme (CCS)?
-Scheme in 1980’s providing funding (incentive) for farmers/land owners in UK who used environmental strategies to conserve biodiversity
-Replaced 2005 with ESS
To qualify:
1. Provide and protect natural habitats
2. Ensure land is well managed
3. Protect natural resources present on their land
4. Conserve traditional crops or animals living on their land
5. Provide visitor learning on conservation
What is a keystone species?
A species that defines and maintains an ecosystem/habitat, and without which the habitat may die or become unbalanced, eg, sea otters and urchins.
What the 3 reasons for maintaining biodiversity?
Ecological:
-Maintaining keystone species and conserving genetic resources
-Maintaining SSSI’s - Sites of Special Scientific Interest, as these sites can contain important science undiscovered, eg, new drug bases
Economic:
-Reducing soil depletion by stopping the spread of continuous monocultures
-Conserves ecotourism, eg, the redwoods in the USA
-Helps drive scientific advancement, eg, PCR and drug development
Aesthetic:
-To maintain habitats for human mental health
What does ex-situ and in-situ conservation mean, and what are examples?
Ex-situ is the conservation of biodiversity by removing it from its natural habitat where it is under threat, and with active human involvement to help conserve it, eg, zoos, seed banks, gardens, etc.
In-situ is the conservation of species in their natural habitat with little to no human involvement, eg, game reserves and marine conservation zones.
What are the 3 domains, and how were they discovered?
- Eukarya - organism’s who contain nuclei
- Bacteria - prokaryotic organisms
- Archaea - prokaryotic organisms, that are different to bacterial organisms
They were discovered by Carl Woese by comparing the genetic code of the 16S ribosomes between animals, as this ribosome is the same in all living organisms.
What is the order of classification?
Dumb King Phillip Came Over For Group Sex
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What is Phylogeny?
The study of evolutionary relationships between organisms, eg, putting animals in an evolutionary/phylogenic tree.
What are Archaea and how are they different from Bacteria?
They are prokaryotic organisms that evolved from Eukarya after bacteria did.
They are different from both for a number of reasons:
1. They have 3 RNA polymerase’s to code for the 3 different types of RNA, whereas bacteria only has 1
2. Their cell walls do not contain peptidoglycan, unlike bacterial cell walls
3. They have cell membrane that contain lipids with hydrocarbon chains rather than fatty acids
Why is binomial nomenclature needed, and what the rules for writing a species name in this way?
It is needed to have a universal and internationally recognised naming system for species, stopping any confusion about species between languages. The way to write the name is to write the genus in a capital letter, the species in a lower-case letter, and in italics or under-lined.
What is a species?
A group of organisms that are very similar in appearance, anatomy, biochemistry, physiology and genetics, and can reproduce sexually to produce fertile offspring.
What is convergent and divergent evolution?
Convergent evolution is evolution that occurs in organisms that are not related, but are anatomically similar due to being subject to similar evolutionary pressures.
Divergent evolution is evolution that results in organisms becoming more anatomically different, represented by a branch from the phylogenetic tree.
How are animals placed onto a phylogenetic tree?
-Using a protein called Cytochrome C
-This is useful as it a protein used in respiration
-This means all eukaryotes have it
-Therefore, the primary structure of cytochrome c can be compared across species, using a matrix, to place them on a phylogenetic tree relative to others
What are the 2 types of classification?
- Artificial classification
- Natural classification
What is artificial classification, and what are it’s advantages and disadvantages?
Grouping organisms based upon like characteristics, eg, organisms that are orange.
Advantages:
-Does not changed based upon further knowledge, ie, both organisms will still be orange
-Convenient
Disadvantages:
-Not useful to find the species evolutionary history
-Provides limited information, ie, organisms are orange
What is natural classification, and what are its advantages and disadvantages?
A detailed study on an organisms many characteristics, eg, genetic, anatomical and molecular evidence.
Advantages:
-Many different characteristics used
-Reflects phylogenetic relationships between species
-Provides information on evolutionary history
Disadvantages:
-May change with further knowledge
What are the 4 different types of classification?
Inter-specific:
-The variation found between species
Intra-specific:
-The variation found between organisms in a species
Discontinuous:
-Variation caused by solely genetic factors
Continuous:
-Variation caused by both environmental and genetic factors
What is continuous and discontinuous data?
Discontinuous:
Data that can be separated into distinct groups, with no middle values, like nominal data, eg, shoe size being 7, 7.5 and 8, not 7.3
Continuous:
Data that could be any data value in a range, so there is no distinct separation, like ordinal or interval data, eg, height in cm
What are the independent sample and the paired sample t-tests?
Independent sample t-test is a test used to investigate the differences between 2 samples (independent measures design)
Paired sample t-test is a test used to investigate differences over time, using the same sample (repeated measures design)
What are polygenes?
A large number of genes that work as a group to control or have an effect on one continuous characteristic.
What is an adaption, and what are the 3 different types?
-An adaption is any variation that helps an organism to survive in its habitat
-The 3 types are behavioural, physical and physiological
-Behavioural - a variation in how an animal behaves, and certain reflexes
-Physical - a change in the physical structure of an organism or cell, eg, bipedalism
-Physiological - a variation in the chemical processes of an organism, eg, the ability to anaerobically respire
What is disease?
A disorder of the mind or body that causes poor health.
How might bacteria act as pathogenic organisms, and what are some examples?
-Prokaryotic organisms
-They reproduce rapidly via binary fission, bursting out of cells, causing damage, and releasing toxins/waste into the bloodstream, inhibiting enzymes or processes
-Some bacteria are non-pathogenic
How might protoctista act as pathogenic organisms, and what are some examples?
-Eukaryotic organisms that are usually spread via vectors
-Divide via mitotic division/reproduce sexually
-They can cause damage as they inhabit cells, ingesting the cell inside, use the cytoplasm as a reproductive medium and burst out of the cell, causing pain
How might viruses act as pathogenic organisms, and what are some examples?
-Not alive, a strand of mRNA surrounded by a protein shell
-Reproduce by taking over cell’s metabolism and producing more viruses via translation
-This reproduction can cause cells to burst, spreading the virus
How might fungi act as pathogenic organisms, and what are some examples?
-Eukaryotic organisms
-Reproduce via spores
-Can cause the area infected to become uncomfortable, swell or become painful
-They feed on living matter, ingesting nutrients and carbs from the host organism
What is transmission, and what are the 3 methods?
Transmission is the process of passing a pathogen from an infected organism to a healthy one.
1.Direct Transmission - transmission of a pathogen via direct contact between a healthy and an infected individual, eg, bodily fluids
2.Indirect Transmission - transmission of a pathogen via other mediums such as the air, water, or other objects in the direct environment
3.Vectors - an organism or intermediary that carries a pathogen from one host to another
What are the 4 different types of direct transmission?
1.Direct contact refers to transmission via direct physical contact between individuals
2.Faecal-oral refers to transmission via direct contact between the mouth and faecal matter, through a number of mediums, eg, water
3.Droplet refers to transmission via tiny water droplets in the air, from the mouth of an infected organism
4.Spores refers to transmission via small reproductive structures in an environment, which, when in a host, grow and cause infection, eg, potato blight spores and wind
What factors affect transmission?
-Overcrowding
-Poor nutrition
-Compromised immune system
-Culture
-Socioeconomic status
-Waste disposal
-Vector distribution
