Topic 4 Flashcards
What is a niche?
= The role and position of a species in an environment
= The precise role of an organism in an environment
- Two species sharing the same habitat will tend to not be in competition w/ each other as they will have a different ecological niche
- If two species live in the same habitat and have the same ecological niche the better adapted organism will outcompete the other and exclude it from the habitat
What is a habitat?
Habitat = the particular place where a community of organisms is found
What is a population?
- a group of individuals belonging to one species
What is a community?
- all the living organisms in an area
What is a species?
= a group of similar organisms which can breed to produce fertile offspring
= a group of organisms w/ similar morphology, physiology, and behaviour
What are some molecular techniques to determine a species?
- DNA
- Morphology
- Physiology
- Behaviour
What are behavioural adaptations?
Behavioural = acts or reactions that an organism, individual or system produces in response to a particular circumstance
- The way it interacts w/ its environment and organisms present, such as, feeding, territory, courtship, escaping predators
What are physiological adaptations?
Physiological = the functions and activities of life or of living matter and of the physical and chemical phenomena involved
- Body chemistry and qualities that help it explore its niche, ie. temp control, camouflage, reproductive strategy, digestion, chemical signalling, venom
What are anatomical adaptations?
Anatomical = the bodily structure of an organism or of any of its parts
What is an adaptation?
Adaptation = a process by which an animal or plant species becomes fitted to its environment
The ability of a new population to adapt to new environments depends on…?
- The strength of the selective pressure
- Size of the gene pool and mutation role
- The reproductive rate of the organism
What are the dynamics of adaptation?
- No organisms will be perfectly adapted to its environment
- Environmental change has a time lag
- Mutations occur all the time naturally
The niche
- Avoids competition
- Interdependence = vulnerable
- Adaptable species are always in competition but less vulnerable to change
What is co-evolution?
Co-evolution = when two or more species reciprocally affect each other’s evolution
What is interdependence?
Interdependence = the dependence that two or more things have on each other
What is natural selection?
Natural selection = the process in nature by which organisms that are better adapted to their environment tend to survive longer and transmit more of their genetics and characteristics to succeeding generations than those less well adapted
What are the assumptions made in order for the Hardy-weinburg equation?
- Large population = everything is equally represented
- Mating is random = doesn’t influence the changing population
- No selective disadvantage/ advantage for any genotype
- No mutations, migration or genetic drift
What is genetic drift?
Genetic drift = the change in frequency of an existing gene variant (allele) in a population due to random sampling of organism
What can the Hardy-weinburg equation be used to show?
- See phenotype/ genotype
- To know how many sufferers/ carriers there are
- To see if assumptions are true
The Hardy-Weinburg Equation
We can find by seeing who suffers from the disease
p can be found by 1 - q = p
Once we have p and q we can find out how many carriers of a disease there are
What are the sources of variation? - Reproductive isolation
- Random assortment
- Crossing over
- Which sperm reaches the egg
- Mate selection/ random/ fertilisation
Mutations
- Gene (point) mutations
- Chromosome mutations
What is biodiversity?
= refers to the variance and variability of life on earth
= the number and variety of different organisms found in a specified area
Why should we protect biodiversity?
- Ensure a stable atmosphere of gases as a source of Oշ
- Is the foundation of human health and welfare
- Essential to the security of our food sources
- Inv. in many medicines
- Biotechnology - value of genetic material in - plants and animals
- Large diversity means less impact from other species
- Needed for long-term sustainability and mitigation of climate change
What is conservation?
Conservation = an ethic of resource use, allocation and protection
What is an endangered species?
Endangered = a species seriously at risk of extinction
- Conservation management: successful if the species is able to retain enough genetic diversity to survive minor environmental changes in their natural habitat
What is the order of classification?
K - kingdom - keep (plants/ animals/ fungi/ prokaryotes/ protists) (PP FAB)
P - phylum - parts (mammals/ reptiles/ fish/ amphibians/ birds) (MR FAB)
C - class - clean
O - order - or
F - family - forget
G - genus - good
S - species - sex
What is Archaea? - Three Domain Theory
Archaea = look like conventional bacteria on the outside but work in different ways
- Ribosomal RNA (rRNA)- since ribosomes have a role in protein synthesis they don’t change during evolution
- Membranes composed of hydrocarbon chains attached to glycerol by ester linkages
- Mutations will impair/ change their functions
What is bacteria - Three Domain Theory
Bacteria = prokaryotic cells that are common in human daily life
- Membranes composed of unbranched fatty acid chains attached to glycerol by ester linkages
- Has unique rRNA to the bacteria indicated by the presence of molecular regions different from rRNA of Archaea and Eukarya
What are Eukaryotes - Three Domain Theory
Eukaryotes = have eukaryotic cells
- Membranes composed of unbranched fatty acid chains attached to glycerol by ester linkages
- Contain rRNA unique to eukarya
Four kingdoms: protista/ fungi/ plantae/ animalia
What is the degenerate code?
Degenerate code = a code in which several code words have the same meaning
What are the differences in ribosomes?
Prokaryotes and archaea = 70S
Eukaryotes = 80S
What are some ways to evaluate scientific ideas?
- It is peer reviewed by scientists who specialise in the area
- Publish in a scientific journal
- Other scientists repeat the experiment to hopefully get similar results
- Other scientists use the theory to make new predictions and experiments
What is species diversity?
Species diversity = the no of different species and the abundance of each species in an area
What is genetic diversity?
Genetic diversity = the variation of alleles w/n a species of a population of a species
What is ecosystem diversity?
Ecosystem diversity = the variety of alleles w/n an area
- This will result in a higher species diversity
How can you measure diversity?
Quadrats/ transects w/ low growing plants
Pooters for insects (a straw to suck up the insects)
Pitfall traps for insects (generally nocturnal ones)
Sweep nets (like ones used for butterflies)
Kick sampling (net underwater and kicking river bed)
Capture/ recapture technique = capturing animals, marking them in a way that doesn’t affect survival chances, catch them again to examine how many are marked
What is the heterozygosity index?
Heterozygosity index = the proportion of genes which are present in heterozygous form
Number of heterozygotes -------------------------------------------------- No. of individuals in the population
The higher the number the larger the genetic diversity = more chance of survival
What is species evenness?
Species evenness = a measure of the relative abundance of the different species making up the richness of an area
- How even is the distribution
What is species richness?
Species richness = no of species per sample/ area
- The more species present the richer the sample
- More money = richer, more species = richer
What is taxic richness?
Taxic richness =measures genetic diversity by using the relationship b/w organisms w/n an area
- The less closely related, the higher the score
What are biodiversity hotspots?
Biodiversity hotspots = an area w/ a particularly high plant biodiversity,
Eg. Mediterranean basin holds 10 % of earth’s plant species
What is sample size rarity?
Sample-size rarity = a measure of how common an organism is
- The less common the greater the weighting
What is germinating?
Germinate = a seed/ spore begins to grow and put out shoots after a period of dormancy
What are tonoplasts?
Tonoplasts = a cytoplasmic membrane surrounding the vacuole
What are amyloplasts?
Amyloplasts = non- pigmented organelle where starch is stored
What is molecular phylogeny?
Molecular phylogeny = analysis of the structures of many different chemicals and genes to identify the interrelationships b/w groups of organisms
What is celluose?
Cellulose = made up of beta glucose
- Produces strong cell walls from cellulose
- Polymer of sugar molecules
- Can build columns and tubes w/ it
Stiffen these cells w/ another polymer called lignin
What is starch?
Starch = made up of amylose and amylopectin = made up of alpha glucose
- Test for starch is iodine (turns it blue/ violet)
How does the formation of a beta polymer work?
- Condensation reaction b/w OH groups, 1st + 4th carbon, forms 1-4 glycosidic bonds
- Forms a long unbranched molecule
- Molecules join at 180 to each other
What is microfibril?
Cellulose chain contains 1,000 to 10,000 glucose units
H bonds b/w neighbouring cellulose chains form bundles = microfibrils
Microfibrils ‘glued’ together w/ branched polysaccharides called hemicelluloses and pectins (amylose and amylopectin)
Pectin acts as a cement in the middle lamella, joining cells together
What is the epidermis?
Epidermis = single layer covering plant
What is vascular tissue?
Vascular tissue = inv. in transport (xylem + phloem)
- NB sclerenchyma fibres surround the vascular bundles (around phloem)
- They harden/ strengthen the vascular bundles
- The cambium separates the xylem and phloem
What are ground tissues?
Ground tissue = contains cells specialised for photosynthesis, storage + support
Water and Mineral transport
- Water in xylem is pulled upwards by the constant movement of water into the leaf caused by transpiration
- Removal of water at top of xylem causes a gradient in hydrostatic pressure, w/ lower pressure at the top
- Water moves down pressure gradient continuously (transpiration stream)
- Cohesion drags it up, adhesion keeps it from falling
What is the movement of water and ions?
Water: soil→root hair cells→xylem
- Osmosis - moves down osmotic gradient
Ions: soil→root hair cells→xylem
- Active transport
What is cohesion?
Cohesion = the attraction of molecules to other molecules of the same kind
What is adhesion?
Adhesion = the attraction of molecules to dissimilar particles or surfaces
What is the xylem?
Xylem = vascular tissue responsible for the conduction of water and nutrients from the roots up the stem to the leaves
What is the phloem?
Phloem = vascular tissue which conducts sugars and ions downwards from the leaves
What is transporation?
Transpiration = the process where plants absorb water through the roots that then evaporates through pores in their leaves, basically water movement in the xylem
What is the stomata?
Stomata = tiny openings to allow plants to exchange the gases necessary cellular processes
What is sclerenchyma?
Sclerenchyma = support tissue composed of any of various kinds of hardwood, fibres and sclereids
What is plasmodesmata?
Plasmodesmata = a narrow thread of cytoplasm that passes through cell walls of adjacent cells, allows communication b/w them
What is the process of water transport?
Evaporation of water from the cells in the substomatal cavity of leaves provides the force needed to draw water up a plant
The channels b/w the cellulose microfibrils in the cell act as capillaries
Capillaries can draw water up them by capillary action
Capillary action is caused by surface tension
As water evaporates, it is replaced by capillary action
The capillaries in the cell walls of leaves produce a pull on the water behind them
The pull then draws water from the xylem and up the stem
This stream of water is the transpiration stream
What is translocation?
Translocation = the movement of organic solutes from source to sink through the phloem by means of mass flow
- Sugar movement in phloem
What are plant fibres?
Plant fibres = long tubes of plant cells
Why are plant fibres strong?
- They’re strong so can be used for ropes or fabrics
Strong b/c of the arrangement of cellulose microfibrils in the cell wall
- A net-like arrangement
- Microfibrils are strong
- Strong b/c of secondary thickening of cell walls
- Forms b/w cell wall and cell membrane
- It is thicker and made more of lignin
- Lignin is a woody substance making them stronger
Tensile strength of plant fibres experiment
- Extract a plant fibre→to use as a test subject→insects on plant = infection
- Attach the fibre to a clamp stand→to keep it steady→heavy (feet)
- Measure the length of the plant fibre→so length can be taken into account
- Add a weight to the end of the plant fibre→to see if it can hold it→heavy (feet)
- Keep adding weights until it breaks→to see how much it takes to break→heavy
- Record the weight the plant fibre breaks at→for validity→weights may go everywhere
- Repeat the experiment with the same type and length of plant fibre→for reliability
- Calculate a mean and draw an appropriate graph→for reliability
What are some sustainable uses of plant fibres?
- Ropes and fabrics can be made instead of using plastic (from oil)
- Meaning less fossil fuels are used up and crops can be regrown
- Products are then biodegradable (broken down by microbes)
- They are easier to grow and process than oil so its cheaper
What are the sustainable uses of starch?
- It can replace plastic made from oil, they’re then bioplastics
- It can replace vehicle fuel, e.g bioethanol
- Meaning less fossil fuels are used up and crops can be regrown
Water and inorganic ions
- Water is needed for photosynthesis, to transport molecules, maintain structural rigidity (from pressure), and regulates temperature
- Magnesium ions for production of chlorophyll for photosynthesis
- Nitrate ions for DNA, protein, chlorophyll production, for plant growth, fruit and seed production
- Calcium ions for cell walls for plant growth
Plant mineral deficiencies experiment
- Make 5 mixtures: all nutrients, no nitrogen, no magnesium, no calcium and then deionised water→to compare against→liquids
- Then split the mixtures up into three test tubes each→for validity→liquids
- Measure the masses of 9 germinated seeds of the same plant, e.g mung beans→to use as test subjects→diseases
- Then place the seeds’ roots in the mixtures with the seeds out of the liquid using cling film→to represent the ground→glass
- Cover the outside of the test tube w/ foil→to prevent light entering and algae growth
- Then place all the test tubes near the same light source and leave for two weeks→to allow for plant growth→light = eyes // burn
- Every day check if the mixtures need topping up to keep the roots suspended→for plant growth
- Carefully remove each plant and blot dry→to not affect mass // for validity
- Measure and record the masses of the plants→to compare
- Calculate the mean change from the results→for reliability
What are the drug testing phases?
- Testing on a small group of healthy individuals to find a safe dosage and any side effects
- Tested on a large group of patients to see how well it works
- Compared to existing treatments using a large sample size
What is a placebo?
Placebos = an inactive substance that looks like the drug but doesn’t do anything
Phase 2
- Tests if the drug actually works and its not the people saying/ believing they’re better
What is a double blind study?
Double Blind Study = neither the patients nor doctors know who has the drug or placebo
Phase 2 and 3
- This reduces bias as attitudes can’t change the results
How to test bacterial growth?
To test it, the conditions have to be right for bacteria to survive and reproduce
- Nutrients are needed to respire and grow
- They may need oxygen for aerobic respiration
- The temp and pH of the environment can not be too high or low
- It affects enzyme activity meaning metabolic processes can’t occur normally
Antimicrobial properties of plants experiment
- Prepare an agar plate and transfer the bacteria using a sterile pipette→to place in a controlled environment // prevent cross-contamination→its bacteria
- Spread the bacteria around the plate using a sterile plastic spreader→for a large SA // to prevent cross-contamination→seriously, its bacteria
- Cover the plate w/ lid→to keep it contained→back to the point it’s bacteria
- Dry and grind each plant you want to test and soak in ethanol→to use as test subjects // to sterilise→ethanol = slip/ flammable/ eyes
- Filter the ethanol off and using sterile forceps dip equally sized sterile absorbent paper in the plant extracts→so the ethanol doesn’t affect it→ethanol
- Leave for one hour→to absorb the plant extracts→liquids // glass
- Place the discs on the agar plate with another equally sized disc of just ethanol→control group→ethanol
- Tape the lid shut, invert and incubate at 25°C for 48 hours→to allow for it to kill the bacteria
- Then remove the lid and make 4 radius measurements of each clear zone and calculate an average→to measure and compare→it’s still bacteria
- Repeat the experiment and create an average→for reliability and validity
What are the purposes of Zoos and seed banks?
Purpose = conserve endangered species of plant and animals
- Extinction of a species/ loss of genetic diversity w/n a species causes reduction in global diversity
- Some are already extinct (dodo) and some are endangered
What are seed banks?
- Store lots of seeds from different species of plants, esp. endangered ones
- Conserve biodiversity and genetic diversity through storing them
- If a plant becomes extinct, the seeds can be used to regrow them
What is the storing process of seed banks?
- Check they have a permit to store the plant
- Dry out the plant
- Move to the dry room, which is at 15°C, for 6 months
- So only a 5% moisture is left, ↓metabolism
Clean them from the rest of plant material, to prevent contamination - Put them through a vacuum to remove weak seeds
- Xray them to make sure they have a healthy embryo
- Dry them out again
- Seal them and store them at -20°C
- Every 10 years take some seeds out to see germination success
- It has to be above 75% for the seeds not to be replaced
What are the advantages of seed banks?
- Cheaper than fully grown plant
- Larger numbers w/ less space
- Less labour required
- Can be stored in any cool dry place
- Less likely to be damaged from disease, natural disasters or vandalism
What are the disadvantages of seed banks?
Testing viability is expensive and time consuming
- Too expensive to store and test all types of seeds
- Can be difficult to collect seeds from remote locations
What are zoos?
- They use captive breeding programmes
- Endangered or extinct in the wild can be bred together, e.g. pandas
- This can help protect genetic diversity and global biodiversity
What are the problems with zoos?
- Animals may not be willing to breed outside of their habitats
- There might not be enough animals of a species to breed successfully
- Age, gender, health, siblings
- Many people think it’s cruel to keep them in captivity
What is reintroduction? (zoos and seed banks)
- Once numbers have increased and the habitat is available they can reintroduced into the wild
- Can bring species back from the brink of extinction
- Can help other organisms who rely on these reintroduced organisms
- Reintroducing plants helps restore habitats
What are the problems with reintroduction?
- They may bring new diseases harming other organisms
- The organisms may not be able to survive in the wild successfully
- E.g open season (the film but w/ a sad ending)
How do seed banks contribute to scientific research?
- Can study how plant species are grown
- Can grow endangered plants useful for new crops/ materials
- Protecting the plants already in the wild
- Can provide knowledge to local people on how to protect plants
- E.g the Millenium Seed Bank Project
- But limited to the small number of seeds that are stored
How do zoos contribute to scientific research?
- Increases knowledge on behaviour, physiology and nutritional needs
Contributing to conservation methods
Can carry out research studies not possible in the wild
- E.g. nutritional or reproductive studies
Educates the rest of the world so they are more interested
- More willing to want the animals to be protected
Can educate local people on why they shouldn’t hunt/ kill them
- E.g. learning elephants don’t like tomatoes in their eyes so tomato bombs are being used to deter elephants entering villages
- Though animals in captivity may act differently to those in the wild
