Biodiversity & Natural Resources Flashcards
BIODIVERSITY
Index of Biodiversity
Comparing Biodiversity of Different Habitats
Used to compare the Biodiversity of Different Habitats
Learn Index of Diversity Equation
Value of 1 means there is no diversity at al
N = total number of organisms of all species
n = total number of organsims of a particular species
BIODIVERSITY
Comparsion of 2 habitats
For Example: What needs to be measured in order to compare 2 rainforests
Measure Species Richness:
Count the number of different species
Determine Population Size:
Number of individuals per species
BIODIVERSITY
Definition of Biodiversity?
Measured by?
The variety of plant and animal life in a particular habitat.
Number of species within a habitat or Genetic Variation within a species.
BIODIVERSITY
Definition of Species?
A group of organisms that can interbreed to produce fertile offspring.
BIODIVERSITY
Definition of Species Richness?
Measures number of species in a habitat.
BIODIVERSITY
Measuring Genetic Diversity?
Equation
Definition of Heterzygote?
Calculate the heterozygosity index:
Number of heterozygotes/ number of individuals within a population
Heterozygote - an individual having two different alleles of a particular gene, giving rise to varying offspring.
BIODIVERSITY
Definition of Endemic?
A species that is found on only one geographical location.
BIODIVERSITY
Definition of Species Eveness?
How relatively abundant each of the species are
BIODIVERSITY
Definition of Niche?
Competition within an Niche?
A role that an organism plays in the ecosystem:
include biotic and abiotic interactions
Exploitation of a particular organsims environment
If 2 species attempt to occupy the same Niche, one will be out-competed untill only one species survives.
ADAPTATIONS
What are the 3 types of adaptations?
- Behavioual
- Physiological
- Anatomical
ADAPTATIONS
Behavioural Adaptation:
The way that an organism acts which increases it’s chance of survival.
ADAPTATIONS
Anatomical Adaptation
Strutural Features of an organism which increase its chance of survival.
ADAPTATIONS
Physiological Adaptation
Internal Features
Processes which occur within the body of an organism to increase chance of survival.
***Metabolic Reactions in response to a stimulus.
What is the effect of interbreeding on Genetic Diversity?
- Increases the size of the gene pool
due to the introduction of new alleles into the population
NATURAL SELECTION
Definition of Natural Selection?
Process by which individuals with a favourable phenotype are more likely to survive and pass on alleles to offspring
Advantageous alleles increase in frequency over time
NATURAL SELECTION
Definition of Evolution?
Change in allele frequency within a population over time.
Allele = an alternative form of a gene
NATURAL SELECTION
How does natural selection lead to evolution?
Random Mutations = New Alleles
1. Advantageous allele frequency will increase overtime due to natural selection
2. Individuals without this will not survive long enough to reproduce
3. This means there is reduced competition for resources
4. Non advantageous allele frequency decreases
Changes to allele frequency leads to evolution within a population
Individuals with ADVANTAGEOUS ALLELE will pass on to their offspring - they are also more likey to survive.
NATURAL SELECTION
Why does Natural Selection Occur?
Types of Selection Pressures
- PREDATORS
- DISEASE
- COMPETITION
Results in differential survival and reproduction
NATURAL SELECTION
The Hardy- Weinburg Principle
- Estimates the frequency of alleles in a population.
- Estimates if allele frequency is changing over time.
NATURAL SELECTION
The Hardy- Weinburg Equation
Key:
P^squared + 2pq + q^squared = 1
p + q = 1
P = Homozygous Dominant Allele
pq = Heterozygous
q = Homozygous Recessive
NATURAL SELECTION
Definition of Speciation?
Development of a new species
- Population of a species become separated from eachother by geographical barriers
NATURAL SELECTION
Definition of Reproductive Isolation?
Occurs when changes in alleles and phenotypes of some individuals in a population:
* prevents them from successfully breeding with other individuals
NATURAL SELECTION
How does Speciation Occur?
SPLIT & ISOLATED POPULATION
different selection pressures acting on 2 groups
If genetic makeup changes so that groups can no longer interbreed
They become a new SEPERATE SPECIES
NATURAL SELECTION
How does reproduction and speciation cause the formation of a new species?
Random Mutation = change in allele frequencies
Population becomes split and isolated
If sufficient selection pressures change the gene pool of both populations that they can no longer interbreed…
POPULATIONS WILL DIVERGE AND FORM SEPARATE SPECIES
NATURAL SELECTION
How do mutations lead to a population becoming a seperate species?
- Mutations results in prodution of new alleles
- Selection pressure cause ADVATAGEOUS ALLELES
- Frequency of advantageous alleles increases
( more individuals survive and reproduce) - After some time, population will not be able to reproduce with another species to produce fertile offspring
CLASSIFICATION
Definition of Classification
A means of sorting organisms into categories based on their relationships using both genotypes and phenotypes.
CLASSIFICATION
What are the 5 kingdoms in the model for Classification?
- Animalia
- Plantae
- Fungi
- Protoctista
- Prokaryote
CLASSIFICATION
What is the Taxonomic Hierarchy of groups?
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
CLASSIFICATION
Name of the system in which each species is named?
Meaning -
Bionomial System
The first part of the name is the genus, the second part of the name is the species.
CLASSIFICATION
Features of Kingdom Animalia
- Multicellular Eukaryotes
- Heterotrophs
obtain energy by ingesting material from other organisms
CLASSIFICATION
Features of Kingdom Plantae
- Multicellular Eukaryotes
- Autotrophs
make their own organic molecules by Photosynthesis
CLASSIFICATION
Features of Kingdom Fungi
- Multicellular Eukaryotes
- Heterotrophs
absorb nutrients from decaying matter after external digestion
CLASSIFICATION
Features of Kingdom Protoctista
- Eukaryote
- photosythesise/ feed on organic matter from other sources
For Example ; algae
CLASSIFICATION
Features of Kingdom Prokaryotae
- Prokaryotic Organisms
For Example; bacteria
CLASSIFICATION
Woese phylogenetic tree
3 Domains:
* Archea
* Bacteria
* Eukaryota
Contain RNA sequences that are unique to their domain.
CLASSIFICATION
Molecular Phylogeny?
The analysis of molecular differences in different organisms to determine the extent of their evolutionary relationship.
CLASSIFICATION
How can molecular phylogeny be used to show two populations are reproductively isolated?
- Comparison of similarities and differences in DNA
- Comparison of Nucleotide Sequences
- Greater number of differences , more likely to be reproductively isolated.
CLASSIFICATION
How does the scientific community evaluate the data?
- Findings published in scientific journals
- Presented at scientific conferennces
- PEER REVIEW
PROPERTIES OF PLANTS
STRUCTURE AND FUNCTION
Plant Cell Wall
- Made of Cellulose
Outer Layer = Middle Lamella
Holds adjacent cells together
Provides support and protection
PROPERTIES OF PLANTS
STRUCTURE AND FUNCTION
Chloroplast
Contained thylakoid membranes which are stacked into grana.
* Contain chlorophyll
Surrounded by the stroma = liquid containing photosynthetic enzymes
PROPERTIES OF PLANTS
STRUCTURE AND FUNCTION
Amyloplasts
Produces and stores starch
* Composed of amylose & amylopectin
- Surrounded by a double membrane
PROPERTIES OF PLANTS
STRUCTURE & FUNCTION
Vacuole
- provides cell support
- Storage for nutrients needed as well as waste materials before removal
Sac filled with cell sap
Vacuole is surrounded by a single membrane, tonoplast
PROPERTIES OF PLANTS
STRUCTURE & FUNCTION
Plasmodesmata
Connect neighbouring cells together
- allows transport of substances between them
PROPERTIES OF PLANTS
STRUCTURE & FUNCTION
Pits
Thin sections of cell wall which allows:
* Easy diffusion
* Enables substances to be transferred between them
PROPERTIES OF PLANTS
Structure of Cellulose
- Polymer of Beta Glucose
- Contains 1,4 glycosidic bonds
- Every other glucose molecule = inverted
- In an unbranched straight chain
Hydrogen bonds join adjacent cellulose molecules together in a cellulose microfibril
PROPERTIES OF PLANTS
Structure of Starch
- Polysaccharide made from alpha glucose
Monomers = chains joined by 1,4 glycosidic bonds
Branches = joined to chains by 1,6 glycosidic bonds
Contains amylose & amylopectin
PROPERTIES OF PLANTS
How does starch relate to its function as a storage molecule?
- Contains glucose needed for respiration
- Insoluble so has no osmotic effect
Contains amylose & amylopectin:
Amylose = coiled making starch compact , more energy can be stored
Amylopectin= branched so can be rapidly hydrolysed
PROPERTIES OF PLANTS
STRUCTURE
Comparison between Cellulose & Amylopectin
- Both polymers of glucose
- Both contain 1,4 glycosidic bonds
Cellulose contains beta glucose whereas amylopectin contains alpha glucose
Amylopectin contains 1,6 glycosidic bonds whereas cellulose does not
PROPERTIES OF PLANTS
Suitable for energy storage?
Amylopectin and Glycogen
- Branched so can be rapidly hydrolysed to release glucose
- Compact so more energy can be stored
- Insoluable so does not have an effect on osmosis
- Energy molcules are too large to diffuse across cell membrane so they can be stored well
PROPERTIES OF PLANTS
How does the structure of Cellulose relate to its function?
Long beta glucose chains are held together by hydrogen bonds to form microfibrils
Hydrogen bonds = strong
So, cellulose is well suited to providing structural support.
PROPERTIES OF PLANTS
Xylem Vessels
Long cylinders of dead tissue with open ends
* Transport Water & Minerals as well as providing structural support
Thickened with a tough substance called lignin
- Inside of Vascular Bundles
PROPERTIES OF PLANTS
What is the purpose of Lignin in the cell walls?
Strength & WaterProofing
Example - In Xylem & Sclerenchyma
PROPERTIES OF PLANTS
Sclerenchyma Fibres
- Dead cells with a hollow lumen and end walls
Provide structural support
Also thickened with a tough substance called lignin
PROPERTIES OF PLANTS
How do cells become lignified?
Example - Xylem & Sclerenchyma
Polymer lignin impregnates the the cellulose wall
PROPERTIES OF PLANTS
How are Xylem Vessels formed?
- After lignification
entry of water and solutes into cells are restricted - Tonoplast Breaks down - Autolysis occurs
Leaves dead empty cells that form a tube
Autolysis = Cell starts to breakdown, cell membrane dissolves and enzymes & other cell contents spill out and digest surrounding tissues.
PROPERTIES OF PLANTS
Phloem Vessels
- Tubes made of living cells
Involved in translocation
Translocation - Movement of food substances and nutrients from leaves to storage organs.
PROPERTIES OF PLANTS
How does the structure of Xylem & Sclerenchyma relate to its function?
cellulose microfibrils form a net like arrangement in the cell walls of the fibres.
Secondary thickening (lignin) strengthens fibre further
Fibre = structually supports the plant
PROPERTIES OF PLANTS
Vascular Bundles
Components for Transport and Support
- Xylem Vessels
- Phloem Vessels
- Cambium Cells
- Sclerenchyma Fibres
- Parenchyma Cells
Cabium Cells - undifferentiated cell, can specialise as plant grows
Parenchyma cells - acts as packing cells between other cells and vessels
PROPERTIES OF PLANTS
Importance of Water in Plants
- Required for photosynthesis
- Maintain rigidity of cells
- Transport of substances
- Thermoregulation
PROPERTIES OF PLANTS
Why are plant fibres useful for humans?
- Sustainable & Renewable Resource
- Products are Biodegradable
- Strong and Cheap
- Can be used to make bioplastics and bioethanol
PROPERTIES OF PLANTS
What are the 3 organic ions important to plants?
- Nitrate Ions
- Magnesium Ions
- Calcium Ions
PROPERTIES OF PLANTS
Function of Nitrate Ions?
How are they transported from root to the leaves.
Supply Nitrogen for production of DNA, proteins and chlorophyll.
Through Xylem vessels in water - Transpiration Stream
PROPERTIES OF PLANTS
Importance of calcium and magnesium in plants?
- Calcium = Form calcium pectate for cell walls growth.
- Magnesium = Chlorophyll production and Enzyme activation.
PROPERTIES OF PLANTS
What are the effects of a shortage of magnesium ions?
- Shortage = limits chlorophyll production
- Lack of glucose due to less photosynthesis
- Cause stinted growth/ discolouration of leaves.
PROPERTIES OF PLANTS
Sustainability
Definition
How can using plant products improve this?
Using resources in a way that also maintains them for future generations.
Plants Fibres = biodegradable & cheap
Starch = extracted from crops and can be regrown
DRUG TESTING & DEVELOPMENT
Drug Testing
William Withering
- Potential useful substance identified
- Trial on small group of paitents with disease
- Large group of paitents used
- General Use
DRUG TESTING & DEVELOPMENT
Drug Testing
Modern Day
- Potential useful substances found
- Active ingredient identified
- Pre Clinical Trial on Animals - Safety/ Toxicity/ Efficacy
- Stage 1
Review of Data - Stage 2
- Stage 3
Approval for Use
DRUG TESTING & DEVELOPMENT
Drug Testing - Stages of Testing
Stage 1
Drug Tested on HEALTHY individuals to test for side affects
DRUG TESTING & DEVELOPMENT
Drug Testing - Stages of Testing
Stage 2
Drug is tested on a group of paitents
DRUG TESTING & DEVELOPMENT
Drug Testing - Stages of Testing
Stage 3
Drug Tested on a LARGE GROUP of paitents
1 group recieves existing treatment others recieve new treatments
DRUG TESTING & DEVELOPMENT
Describe how clinical trials of a vaccine would be conducted?
- Small group of healthly volunteers are given volume to test for side affects.
- A group of people at risk of contracting disease is given the vaccine.
- People who develop disease are monitored.
DRUG TESTING & DEVELOPMENT
The role of a placebo in producing valid conclsions.
Stage 3
Placebo provides control group for comparison
This ensures active ingredient is causing the effect.
DRUG TESTING & DEVELOPMENT
The role of a double blind trial in producing valid conclusions.
Stage 3
Double blind trial, neither doctors or paitents know who has been given the drug.
Ensures bias is removed from the trial
DRUG TESTING & DEVELOPMENT
How can a safe dose of serious illness drug be determined?
- Test the drug on HEALTHY individuals
- Test drug on a group of individuals WITH ILLNESS
- Gradually INCREASE dosage to determine its effects
DRUG TESTING & DEVELOPMENT
Conditions required for bacterial growth.
- Correct Temperature & PH for metabolic enzymes
- Source of nutrients required for respiration
- Suppy of Oxygen (for aerobic bacteria)
CONSERVATION
Definition of Conservation
The protection & management of species & habitat
In order to maintain biodiversity
CONSERVATION
What are Captive Breeding Programmes?
Endangered species are carefully bred to increase genetic diversity and population size.
CONSERVATION
How would captive breeding programmes prevent a species becoming endangered?
- Relocation causes reproductive isolation
- Use of studbook
- Increase in number of another species
- Reintroduction to naitive habitat
CONSERVATION
Role of Zoos in animal conservation?
- Protection from poachers
- Repopulation - species can increase in numbers
- Education about conservation - importance of breeding programmes
- Research - discovering better nutrition to improve animal health
CONSERVATION
Explain how breeding programmes in zoos maintain genetic diversity of captive populations.
- Animals are selected to prevent an interbreeding depression
- A stud book is used to select individuals for mating
- There is an exchange of animals between zoos.
CONSERVATION
EX-SITU CONSERVATION
Advantages & Disadvantages
Examples - Captive Breeding Programmes & Seed Banks
ADVANTAGES - Requires little space, predators & poachers
DISADVANTAGES - Expensive , disease spreads quickly & can’t fully recreate natural habitat.
CONSERVATION
Purpose of Seed Banks?
Store a large number of seeds to conserve genetic diversity and prevent plant species from going extinct.
CONSERVATION
Suitable Conditions for keeping seeds in a bank.
Cold & Dry Conditions
CONSERVATION
Benefit of drying seeds before storage?
Extends storage time of seeds
- As drying prevents germination of seeds
