Flashcards in Topic 4 Deck (92):
1
What is a species
a group of organisms with similar morphology, physiology and behaviour, which can interbreed to produce fertile offspring, and which are reproductively isolated from other species.
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What is Biodiversity
The variety of plant and animal life in the world or a habitat
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What is Endemism
Species in a defined geographical location and only that location
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What is a Habitat
Place where an organism lives
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What is a Population
Group of interbreeding species
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What is a community
When there are various populations in a habitat
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What is the heterozygosity index
H = number of heterozygotes /population
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What are the equations used for measuring biodiversity
H = number of heterozygotes /population
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What is a niche
the way an organism exploits its environment e.g food, shelter and time
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When are two species in competition with eachother
• If two species in a habitat that are not in competition they do not control the same niche
• If two species control the same niche they will be in competition, and the better adapted organism will win
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How does adaptation link with competition
• Organisms adapt to exploit niches better for a higher change to survive
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There are three areas where adaptation can occur in a species what are they
Behavioural
Physiological
Anatomical
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What is behavioural adoptation
How the organism acts e.g leaves growing towards the sun, feeding times
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What is Physiological adoptation
Change in location
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What is Anatomical adoptation
Physical characteristics e.g fluffy bumble bees = more pollen
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What is co-adoptation
Two organisms become dependent on each other
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How does natural selection take place
1. Naturally occurring mutation and genetic variation leads to new alleles
2. Change in environment causes the selection pressure to change
3. New allele becomes advantageous meaning the organism is more likely to survive and produce offspring
4. Offspring is more likely to inherit this allele and it therefore becomes more common in the population
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When does natural selection take place
• These changes occur over generations and leads to evolution (the change in allele frequency in a population over time)
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What is the purpose for the hardy weinberg equation
Looks for changes in allele frequency
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What is the hardy weinberg equation and why does the equation = 1
p² + 2pq + q² = 1 (always equals 1 because there is only one allele)
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What do all the symbols mean in the hardy weinberg equation and what does the answer represent
P² = The frequency of homozygous dominant allele
2pq = The frequency of heterozygous alleles
q² = The frequency of homozygous recessive alleles
Answer is a percentage (%) e.g 0.7 = 70%
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What is speciation
When a new species is developed and is productively isolated
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What is classification and what is it based off
• Organising the variety of life based on relationships between organisms
• Based off phenotypes which can be found using DNA analysis (e.g sharks and dolphins have no relation)
• Classification is used to look at evolutionary relationship
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What does Taxonomy mean
The scientific study of putting organisms into hierarchical taxa (groups)
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What is the main hierarchy of groups
Kingdom
1. Phylum (classification according to body shape)
2. Class ()
3. Order ()
4. Family ()
5. Genus ()
6. Species (morphology, physiology, behaviour interbreed to produce fertile offspring and reproductively isolated)
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How many kingdoms are there and what are they
Animalia
Plantae
Fungi
Protoctista
Prokaryotae
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What does the Animalia kingdom consist of
multicellular eukaryotes that are heterotrophs (have energy as readymade organic molecules by ingesting material from other organisms)
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What does the Plantae kingdom consist of
multicellular eukaryotes that are autotrophs (make their own organic molecules by photosynthesis)
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What does the Fungi kingdom consist of
multicellular eukaryotes that are heterotrophs but absorb their energy through decaying matter after external digestion
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What does the Protoctista kingdom consist of
eukaryotes that photosynthesise or feed on organic matter from other sources but are not included in the other kingdoms, incused single celled protozoa such as algae
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What does the Prokaryotae kingdom consist of
prokaryotic organisms, includes bacteria and blue-green bacteria
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What does the scientific community in the category of developing domains
• Community carefully checks data for reliable and valid results
• For archae Carl Woese found this category, but didn’t do shite to tell people about it as he was to shy to go to conferences
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What are the three domains used today
Bacteria, Archaea and Eukaryota
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What do modern evolutionary systems try to do
attempt to show evolutionary relationships between species
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How is classifying helpful to medication
Looking for relationships between organisms that are already used in medication
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What is used to measure genetic diversty
The Diversity index D=(N(N-1))/(∑n(n-1))
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What is the name given for the number of species in a habitat
Species richness
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What do all the symbols in the diversity index mean
D = diversity index
N = total number of organisms for all species
N = total number of organisms in each species
39
What is the structure of a plant cell
Large valcuole in the center
Around the vacluole:
vacuolar membrane
All the usual stuff Eukaryotes have
Chloroplast
Amyloplast (contains starch grains)
40
What is cellulose
A polysaccharide, that is an important part of the cell wall.
41
What is the structure of cellulose
• Made of β-glucose
• Bonds from in condensation reaction forming 1,4 glyosidic bonds
• 1000 – 10000 glucose units to form a straight chain
• Hydrogen bonds on -OH groups with neighbouring chains to form microfibrils which are made of 60-70 cellulose molecules
• Hemicellulose and pectins are used to glue the microfibrils in place and create a matrix to reinforce the cell wall
• The microfibrils are laid down at different angles to make the wall stronger and more flexible
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Why must plant cells be stiff
for mechanical support but must also still be allowed to transport substances
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What are the two transport tubes in plant cells
Xylem and Phloem cells
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What is the function of Sclerenchyma and what do they look like
Columbus of their fibres provide cell walls with support, are chisel shaped and contains lignin
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What are xylem vessels used for
For water and minerals transport
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What is the structure of a xylem vessel
Has stiff cell wall, is made of dead cells
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What are Phloem tubes used for
Long tubes that transport organic solutes
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What is the structure of Phloem tubes
Does not support the plants structure because it does not have stiff cell wals
49
How do xylem vessels form and explain the process
• Autolysis (cell contents is broken down) of cell content leaves a dead empty cell as a tube
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How are the xylem vessels waterproof
cells have been lignified so they are waterproof
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How is water transported in xylem vessels
• Diffusion gradient, as the plant transpires the cavity provides enough force to drag the water up
• This movement is called the cohesion-tension theory
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How do xylem vessels transport water and give examples of ions transported
• Transports ions in this mass flow system
• Nitrate --> needed to produce amino acids
• Magnesium --> needed to make chlorophyll
• Calcium --> stunts growth due to cell wall structure and permeability
53
What is the epidermis
dermal tissue
54
What are the tree types of tissue plants have
Epidermis
Ground tissue
Vascular tissue
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What is the Vascular tissue
contains the vascular bundle and sclerenchyma
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What are the components in a cross section of a plant stem
Epidermis (contains stoma)
Collenchyma tissue
Parenchyma tissue that contains:
Vascular bundel that contains:
Sclerenchyma
Phloem tube
Xylem vessel
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Explain the cohesion-tension theory and how can it help the plant
• Water has strong bonds between its molecules that keeps it together
• Some molecules make bonds with the cell wall
• Temperature effects density of water so when plants are living under ice of a frozen lake they will not freeze as the ice will float to the top, and they are at a lower point where the temp is higher
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What are most of the cells in a phloem cell
Degenerate (dont do anything)
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What does translocation mean
Mass transport of organic molecules
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What is the structure of phloem cells
Mostly a fluid space called the lumen
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What components surround the phloem plants
Perforated walls are sieve plates
• Area between sieve plates is called the sieve tube element
• Next to the sieve cells are the companion cells, these perform the metabolic functions for the sieve cells
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How do the phloem and xylem work together
• Sugars and aminos made in the leaf made for energy storage or growth are transported around the plant via the phloem vessels
• Mineral ions from root via the phloem into the xylem to be transported upwards, and then to the leaf via the phloem again
• Water travels up the xylem and then some travels back down in the phloem
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What does Turgid mean
A cell is completely full, if a plant loses water it loses turgidity causing the plant to wilt
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What are uses for plants
• Textiles
• Heavy metal absorption
• Biocomposites fibres are mixed with plastic to make it stronger than plastic alone (biodegradable and renewable)
• Bio fuels
• Drugs (comes later)
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How are plant fibres extracted
Enzymes (sometimes from bacteria), or chemicals are used to dissolve or digest the plant material around the durable fibres
66
What are anitbacterials
Toxic chemicals that kill bacteria
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Why do plants use antibacterials
toxic chemicals to defend themselves
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What can humans use antibacterials for
Medicine
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What are the stages of drug trials and explain what happens in them
1. Pre-clinical testing:
• Lab studies on cells, animals and tissue culture to see whether it is effective
• Takes several years
• Animal trials make a base for human trials
2. Clinical trials – phase 1:
• Small group of volunteers given different doses
• Volunteers are normally healthy but can be sick
• Confirms if drug is absorbed, metabolised, distributed and excreted
• Different doses are monitored
3. Clinical trials – phase 2:
• A group of 100-300 volunteers with disease treated to look for drug effectiveness
4. Clinical trials – phase 3:
• Large group of patients 1000-3000 are divided into two groups
• One group is given a placebo, the other the real thing
• Neither patient or doctor knows who has the placebo or the drug (double-blind randomised controlled trial)
• Statistic results
5. After licensing:
• Data is continued to be collected for effectiveness and safety
70
How do bacteria reproduce
asexually in the process called binary fission
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What is binary fission
DNA is replicated, cell contents is synthesised and cell divides into roughly two equal half’s
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What conditions are needed for optimum bacterial growth
sufficient nutrients and O2, optimum temp and pH, no toxic waste build up
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What are the stages of bacterial growth
1. Lag phase -> cells adjust to conditions
2. Log or exponential phase -> cells divide at fastest possible rate for the given conditions
3. Stationary phase -> limited growth due to a negative change in the conditions
4. Death or logarithmic decay phase -> number of cell deaths is greater then cell growth
74
Why are seeds importat
Because they:
• Holds a lot of starch (does not dissolve in water)
• Protects the plant embryo
• Aids in dispersal
• Provides nutrition for the new plant
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What can starch be used for
Starch is used in adhesives, paint, textiles, plaster, insulator, conditioner, sun screen and anti-perspirants
supper absorbent
foam
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How can starch be made bigger and harder
When heated in water the starch is able to absorb water causing it to expand, once it cools it hardens
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How is starch made into a super absprbant
if it is chemically cross linked, gelatinised (made into jelly) and then dried it enables the particles to take in lots of water when rehydrated
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How is starch made into foam
can from a plastic mass, with a water content of less than 10% gelatinisation occurs at temperatures way over waters boiling point, if the pressure is also raised a plastic mass forms, and with a quick release of the pressure the starch expands forming foam
79
What are vegetable oils used for
Making fuel
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What are the problems preventing sustainability
• Burning fossil fuels contributes to global warming via the greenhouse effect
• Oil reserves will eventually run out
• Plastics from these fossil fuels produce non-biodegradable waste
• Conflict between weather crops should be used for fuel or food
• Using paper bags instead of plastic ones wont work cuz rain will delete them, so plant-based plastic bags can be used and they will still biodegrade
• Limited space --> land not suitable, needed for wildlife or water conservation, increasing human population, more costly to produce things using plants
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What are zoos used for
Money, research, education and helping endangered species
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What does In situ mean
on site
83
What does Ex situ mean
off site
84
What do captive breeding programs do
• Successfully breeding animals
• To increase the number of individuals of the species
• Maintain genetic diversity within the captive breeding population
• Reintroducing animals into the wild if possible
85
How can genetic variation be lost
Genetic drift
Inbreeding
Inbreeding depression
86
What is genetic drift
In small populations some alleles may not be passed on to the offspring which leads to a decrease in genetic variation
87
What is inbreeding
In small populations the likelihood of inbreeding is higher, this will cause the frequency of homozygous genotypes to increase and heterozygous to decrease
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What is inbreeding depression
When individuals inbreed the offspring is more likely to get homozygous recessive genotypes which often have harmful effects
89
How do zoos maintain genetic diversity
• Maintaining a large size of population is the best way to do this
• Keeping studbooks these holds the genetic history and location of all the captive animals in the zoo, these are used to plan which animals are to breed with each other and weather a new animal will need to be transferred into the zoo
90
Why was the millennium seed bank founded and what does it do
• Plants are threatened worldwide by habitat destruction, to combat this seed banks and botanic gardens have been made
• The MSB project is to conserve seed samples from threatened species of plants
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What percentage of seeds does the millennium seed bank want to have by 2020
Aim is to have 25% of the worlds species by 2020
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