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36 Cards in this Set
- Front
- Back
What are natural classification systems based on? |
The evolutionary relationships and genetic similarities between organisms
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What are artificial classification systems based on?
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The appearance rather than genes
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What is the order of the classification systems?
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Kingdom
Phylum Class Order Family Genus Species |
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What is a species?
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A group of organisms capable of interbreeding to produce fertile offspring
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What is a genus?
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A group of closely related species
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Why can it be difficult to classify organisms into the distinct groups?
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Many organisms share characteristics of multiple groups
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What does DNA sequencing allow us to see?
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The genetic differences between different groups
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What is asexual reproduction?
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The organism makes a copy of its self to create offspring. Eg bacteria
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What are hybrids?
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Created when a male and female from different species breed.
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Why are hybrids difficult to classify?
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They are often infertile and so aren't a new species
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What is the binomial system?
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A two–part naming system
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What does the first and second part of the binomial system refer to?
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First = genus
Second = species |
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Why is the binomial system important?
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It is used by scientists all over the world so despite speaking other langauges they refer to a particular species by the same name
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Why might closely related species look different?e
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Evolved in different habitats
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What is a pyramid of biomass?
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Each bar/level shows the dry mass of living material at each stage
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Why are pyramids almost always pyramid–shaped?
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Because biomass is lost at each stage in the food chain
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Why is measuring dry biomass difficult?
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You have to kill the organism
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What are pyramids of numbers?
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Each bar/level shows the number of organisms at that stage of the food chain
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What is energy lost through at each stage of food chains?
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Respiration, as heat, egestion and excretion
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What is the equation for efficiency?
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Efficiency = useful energy output/ total energy input
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What is interspecific competition?
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Competition between different species
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What is intraspecific competition?
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Competition between the same species
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Which type of competition has the greatest impact and why?
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Intraspecific because the organims are competiting for the exact same resources
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Why are predator and prey relationships always out of phase?
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It takes time for changes to effect the species
Eg. reproduction or death |
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What is a parasite/parasitic relationship?
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An organism which lives off a host. It takes what it needs but does not give anything back which often harms the host.
Eg. Fleas on a dog |
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What is a mutualistic relationship?
Give an example |
Where both organisms benefit
Eg. Ox–peckers and buffalo |
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What is an adaptation?
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A feature that makes an organism better suited to their environment
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What is a specialist?
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An organism that is specifically adapted to one habitat
Eg. Giant pandas and bamboo |
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What is a generalist?
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An organism that are adapted to survive in a range of habitats
Eg. Black rats = forests, cities, farmland |
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What are "extremophiles"?
Give an example |
Organisms that are adapted to extreme conditions of temperature or pH
Eg. Extremophile bacteria do not denature at high temperatures Eg. Organisms in very cold environments have antifreeze proteins |
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What are 3 anatomical adaptations to cold environments?
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– A thick coat or fat/blubber = insulates |
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Explain counter current heat exchange |
– Blood vessels pass close to each other and allow heat to transfer when the blood flows in opposite directions |
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What are 3 behavioural adapations to cold environments?
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Migration to warmer climates
Hibernate = saves energy Huddle together = keep warm |
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What are 3 anatomical adaptations to hot environments?
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– Small body (Large surface area to volume ratio) = lose more body heat |
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What are 3 behavioural adaptations to hot environments? |
– Go in the shade or underground = reduce heat gain |
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What are four adaptations cactus have to dry conditions? |
– Thick waxy cuticle and spines = reduce water loss |