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Higher Biology - Unit 3
Terms in this set (105)
Give some examples of human activities which are contributing to current extinction events?
Overexploitation/Habitat degredation/Introducing invasive species/Pollution/climate change
What are the measurable components of biodiversity?
Genetic diversity, species diversity, ecosystem diversity
What is species diversity?
The species richness - number of different species and The relative abundance - proportion of each species present
How can having a dominant species affect species diversity?
Dominant species reduces relative abundance of other species which lowers species diversity.
What is genetic diversity?
Number and frequency of alleles present in a population
What is ecosystem diversity?
Number of distinct ecosystems in an area.
What is the bottleneck effect?
When a large percentage of population is lost leading to reduced genetic diversity of survivors. Can lead to inbreeding depression.
Which factors can affect biodiversity of an island?
Size of island and Distance from mainland
How does habitat fragmentation affect biodiversity?
Leads to reduced habitat area so reduced resources. Lowers biodiversity as species have to compete for resources and some will become extinct.
Why are habitat corridors used?
To join habitat fragments allowing members to colonise an area and to mate.
What is meant by an introduced species?
Foreign species moved intentionally or accidentally into a new area.
What is meant by a naturalised species?
Foreign species who are able to survive and reproduce in their new habitat.
What is meant by an invasive species?
Foreign species who reproduce rapidly and outcompete with native species
Which factors allow introduced species to become invasive?
Free of their usual competitors, predators, pests and parasites so can outcompete native species.
What is meant by overexploitation?
Removing organisms from environment faster than they can be replaced by reproduction.
What is meant by social hierarchy?
The order of feeding dependant on social status
Why can a social hierarchy be beneficial?
Means that aggression is ritualised, keeps real fighting to a minimum, ensures fittest individuals survive to pass on genes, leads to experienced leadership
What are the advantages of cooperative hunting?
Larger kills than when hunting alone; Individuals gain more energy than if hunting individually; Subordinates benefit from share of kill as well as dominant individuals
What are the benefits of social defence?
Increased protection, more chance of seeing predators
What is meant by altruism?
When the donor is harmed by the behaviour but the recipient benefits
What is meant by reciprocal altruism?
When the altruistic act is returned to donor in future
What is meant by kin selection?
Providing resources or protection to related individuals - donor gains indirectly through survival of offspring who have some shared genes with donor
Why do social insects provide resources to their queen?
Queen is related to all members of hive so workers benefit indirectly through queen passing on genes she shares with workers
What is a keystone species?
A species which plays a vital role for the survival of other species in an ecosystem (e.g. bees acting as pollinators)
Why do primates have long periods of parental care?
To allow for offspring to learn complex social behaviours
What methods are used in social groups to reduce conflict?
What is meant by ritualistic display?
Making self look bigger and more threatening e.g. baring teeth, raising heckles, banging chest
What is meant by appeasement behaviour?
Reverse of threat display to show submission. Includes behaviours like grooming, submissive facial expressions, certain body postures, sexual presentation
Which factors can influence the social structures of primate groups?
Ecological niche, resource distribution and taxonomic group
What is meant by an alliance?
Relationships formed between individuals which increase social status, maintained by grooming
How can alliances benefit organisms?
Increases social status of individuals which can lead to increased access to food or mates
What is meant by symbiosis?
Co-evolved relationship between members of two different species
What are the two types of symbiosis?
Parasitism and mutualism
What is meant by parasitism?
When the parasite benefits by gaining energy or resources and the host is harmed
What is a parasite?
An organism which gains energy from the host at the hosts expense
What is meant by mutualism?
When both species benefit from the relationship
What is a vector?
Carries a parasite from host to host
Why might parasite lifecycles involve the use of a secondary host?
If they have no method of locomotion, allows them to survive until back in contact with primary host
What are some examples of mutualism?
Coral polyps and zooxanthella - coral benefits by receiving carbohydrates from photosynthesis and zooxanthella get secure habitat.
What are the costs of providing good animal welfare (using free-range farming techniques)
Financial cost of providing high quality food and protection from predators; lower yield per unit area
What are the benefits of providing good animal welfare (using free-range farming techniques)
Higher value of product, good public relations, healthier animals, lower risk of disease spread
What are some indicators of poor animal welfare?
Misdirected behaviour, stereotypy, failure of reproductive or parental behaviour, altered levels of activity
How can poor animal welfare be overcome?
Enriching animals environment, providing company
What is the term which describes the study of animal behaviour?
What is meant by monoculture?
Growing a crop with only one species, increases chances of pest or disease outbreak
What is a perennial plant?
Lives for many years
What is an annual plant?
Life cycle occurs in one year
What traits do perennial weeds have?
Storage organs and vegetative reproduction
What traits do annual weeds have?
Large number of seeds, long term seed viability, short life cycle, grow rapidly
What is a fungicide?
What is a herbicide?
What is an insecticide?
When would you use a selective herbicide?
On grass crops where only weeds with broad leaves are affected
When would a systemic herbicide be useful?
If weed has underground storage structures that could regrow if left behind
What are some examples of cultural methods of crop protection?
Growing a cover crop; Ploughing; Removal of alternative hosts; Crop rotation
What would be the characteristics of an ideal pesticide?
Specific to pest, short lived, safe
What is bioaccumulation?
When the pesticide remains in tissues over time and builds up faster than it can be removed
What is biomagnification?
When the concentration of pesticide increases at each trophic level in food chain and can reach toxic levels near top
What is biological control?
Use of a natural predator to control pest species
What are the risks associated with organisms used for biological control?
Could become invasive, could eliminate other species, could reduce biodiversity
What is integrated pest management?
Use of biological control and chemical control
What is meant by productivity?
Rate at which plants generate new biomass
What is meant by economic yield?
Mass of desired product (e.g. grain)
What is meant by biological yield?
Total plant biomass produced (includes unneeded parts)
The purpose of replicating treatments in a field trial is to?
Take into account the variability within the plants being grown
The purpose of carefully selection of treatments in a field trial?
To ensure valid comparisons can be made
The purpose of randomising treatments in a field trial?
To eliminate bias when measuring the effects of treatments
Which characteristics may plant breeders try to select for?
Improved yield; Improved resistance to pests or disease; Ability to thrive in particular environments
What is meant by discrete variation?
Fits into discrete categories
What type of inheritance causes discrete variation?
Single gene inheritance
What is meant by continuous variation?
Wide range of characteristics
What type of inheritance causes continuous variation?
What is a test cross?
Used to identify organisms with unknown genotypes
How is a test cross conducted?
Cross unknown with homozygous recessive
What is meant by inbreeding?
Crossing related individuals
What is meant by outbreeding?
Crossing unrelated individuals
Why is inbreeding useful?
Ensures offspring receive alleles for desired characteristics
Why can inbreeding be harmful?
It can lead to inbreeding depression
What is meant by inbreeding depression?
A build up of homozygous recessive deleterious alleles
Why is inbreeding depression less likely to occur in plants?
Years of natural selection eliminates deleterious alleles
What is meant by an F1 hybrid?
Produced by cross between two genetically dissimilar parents who have desired traits
Why can the F1 hybrid be useful?
Show hybrid vigour - increased yield, fertility or other beneficial characteristics
How can offspring showing the desired F1 traits be maintained?
Back cross with parents or maintain and continue to breed original parents
Why is the F2 generation produced by crossbreeding often not useful?
Shows genetic variability so not all offspring will show desired traits
Why can the F2 be sometimes useful?
Introduces new variation
How could breeders identify organisms with particular alleles without doing test crosses?
How could breeders create organisms with particular alleles without breeding?
What is an action spectrum?
Shows the rate of photosynthesis at different wavelengths of light.
What is an absorption spectrum?
Shows which wavelengths of light have been absorbed by plant.
Which wavelengths of light are absorbed by chlorophyll?
Which wavelengths of light are absorbed by the carotenoids?
What is the advantage of having the carotenoid pigments?
It extends the range of wavelengths of light that can be absorbed by plants.
What are the three fates of light when it strikes a leaf?
Absorbed, reflected, transmitted
Describe what happens in photolysis?
Light energy excites electrons which are passed into electron transport chains to generate ATP.
Energy is used to split water into hydrogen which is picked up by NADP and oxygen which is evolved.
Describe what happens in the calvin cycle?
Carbon dioxide combines to RuBP to form intermediates. Intermediates are combined with hydrogen supplied by NADPH and ATP is used to form G3P. G3P molecules are either combined or used to regenerate RuBP.
Which enzyme is responsible for fixing Carbon Dioxide to RuBP?
Which coenzyme combines with hydrogen and takes it to the calvin cycle?
What happens to the glucose made by photosynthesis?
Either used in respiration, used to synthesise starch, used to synthesis cellulose or used in other biosynthetic pathways.
What is food security?
Having access to a sufficient quantity and sufficient quality of food.
What is meant by sustainable food production?
Growing food without degrading natural resources on which agriculture depends.
How can we improve crop production with limited area for crop growing?
Growing higher yielding cultivars; Protecting crops from weeds and pests; Using fertilisers; Identifying and reducing the limiting factors of photosynthesis
Why is farming livestock less efficient than farming crops?
Energy is lost at each trophic level
THIS SET IS OFTEN IN FOLDERS WITH...
Higher Biology Unit 2
Higher Biology Unit 1
Higher Biology - Unit 2
Higher Biology Unit 1
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