ecosystems & population Flashcards
what are the classifications of organisms from simplest to most complex?
cell, tissue, organ, organ system, complete organism
what are the classifications of biomes from least complex to most?
species, population, community, ecosystem, biosphere
what is a habitat?
an area or place in a biome with a specific set of characteristics in which a species live
what is an example of a habitat?
squirrels live in trees
what is a range?
geographical area where the population of species is found
what is an example of a range?
raccoons live in many parts of Canada
what is a population?
same species, same area, same time
what are the two categories for population limiting factors?
- internal factors
2. external factors
what will happen if population growth isn’t balanced?
organisms would reproduce out of control
what are the internal limiting factors?
- birth potential
- capacity for survival
- breeding frequency
- length of reproductive life
what is birth potential?
max number of offspring per birth
what is capacity for survival
number of offspring that reach reproductive age
what is breeding frequency?
number of times a species reproduces in a year
what is the length of reproductive life?
the age of sexual maturity and the number of years an individual can reproduce
what is carrying capacity?
the theoretical maximum population size that an ecosystem/environment can maintain over an extended period of time (BR = DR)
what do abiotic and biotic factors do?
they limit the number of individuals in a population
what are the external limiting factors?
abiotic and biotic factors
what are biotic factors?
living factors that influence an organism
what are abiotic factors?
non-living factors that influence an organism
what are examples of abiotic factors?
soil type, moisture, humidity, temperature, water source
what are three biotic factors?
- competition
- predators
- parasites
what is intraspecific competition?
members of the same species competing for resources
what is interspecific competition?
members of different species competing for resources
what is predation?
consumption of one organism by another
what is parasitism?
when one organism (the parasite) benefits from another (the host), the host is harmed in some way
what are the two types of competition?
intraspecific and interspecific
what are the two types of sections ecologists use to sample population?
- transect
2. quadrat
what is a community?
multiple populations, same area, same time
what is an ecosystem?
multiple different populations interacting within the same environment
what are the two types of factors affecting ecosystems?
- density dependant factors
2. density independant factors
what are density dependant factors?
- factors in an ecosystem that affect members of a population because of population density
- often biotic factors
- ex. shortage of food, disease
what are density independent factors?
- factors in an ecosystem that affect members of a population regardless of population density
- often abiotic
- ex. natural disasters, loss of habitat
what is an ecological niche?
the role that a species’ members play in an ecosystem (aka. a species’ job in the ecosystem)
what is an indicator species?
a species that is very sensitive to small changes in an ecosystem and its environmental conditions, it lets us know when there is something wrong within the system
what is taxonomy?
the practice of classifying living things
what did Aristotle do?
he discovered the two Kingdoms: Plant or Animal
what did Haekel do?
he added a 3rd Kingdom: Protista
what are the 6 Kingdoms?
- Plantae
- Animalia
- Protista
- Fungi
- Eubacteria
- Archaeobacteria
what are the 3 domains?
- Bacteria
- Eukarya
- Archaea
who discovered the Plant and Animal Kingdoms?
Aristotle
who discovered the Protista Kingdom?
Haekel
who created “Classification”?
Carl Linnaeus
what are the 7 subdivisions of a Kingdom from broadest to most specific?
Kingdom, Phylum, Class, Order, Family, Genus, Species
what is the acronym for the subdivisions of a Kingdom?
King Philip Came Over For Good Soup
what did Carl Linnaeus do?
he created classification
what is a species?
a group of organisms that look alike and can interbreed under normal conditions to produce fertile offspring
what is adaptation?
a structural, behavioural or psychological process that helps an organism survive and reproduce
can adaptations be learned?
no you must be born with them
do adaptations happen quickly?
no they are gradual changes that take place over time
what is the result of a population that reproduces quickly?
they adapt quickly
can individuals adapt?
no only populations
what must happen in order for an adaptation to occur?
variations of that trait must be present in the population/among the species
what is a variation?
a visible or invisible difference from one individual to the next
what is the result of an advantageous variation?
it is more likely to be passed on, it will then become more common from generation to generation until it becomes a trait of the population
what are the two sources of variation?
- sexual reproduction
2. mutations
which source of variation has a higher chance of variation?
sexual reproduction because genes are passed down to offspring
what are mutations?
changes/mistakes in the genetic material of an organism , they can be visible or invisible
how do mutations happen?
they can be natural or caused by a mutagen
what are the three types of mutations?
- neutral
- harmful
- beneficial
what is a selective advantage?
a characteristic that improves an organism’s chance of growth, survival and reproductive ability
what is fitness?
the ability to successfully reproduce
what is a selective disadvantage?
a characteristic that does not improve survival capabilities
do all mutations lead to adaptations?
no
What did Charles Darwin find?
he found fossils that closely resemble current life forms, species living in South America don’t resemble those living in Africa and 13 similar species of finches with slight variations and distinct adaptations
what is Darwin’s theory?
theory of natural selection; through generations of surviving, a trait becomes more common as it is naturally selected for, maybe so common that is becomes a characteristic of that species
what is natural selection?
natural selection is the process of a population changing because individuals with certain traits can survive better and pass on these traits to their offspring
what must be present for natural selection to occur?
there must be variety or diversity within a species
what is selective pressure?
any phenomena that alters the behaviour and fitness of living organisms
what is the driving force of natural selection?
selective pressure
what are the 5 aspects of Darwin’s theory of natural selection?
- overproduction
- competition
- variation
- survival of the fittest
- origins of new species
what is overproduction?
when more offspring are produced than are intended to survive
what is survival of the fittest
an organism that has a trait that somehow gives it an advantage over other organisms of the same species in that environment
what is the theory of evolution based on?
- changes in DNA (mutations)
2. pressure from the environment
what are the two types of evolution?
- divergent evolution
2. convergent evolution
what is divergent evolution?
members of a species develop variations and differences
what is convergent evolution?
when members of unrelated species start to develop similar traits
what is phylogeny?
the history of evolution of a species
what are the 7 types of evidence of evolution?
- fossil record
- radioactive dating
- biogeography
- anatomy
- embryology
- biochemistry
- artificial selection
what is palaeontology?
the study of fossils
when are fossils formed?
when the bodies of organisms become trapped in sediments
what are transitional fossils?
fossils that show links between groups of organisms that help fill in the gaps in fossil records
what are index fossils?
a fossil used to determine the age of a fossil, rock or the rock layer it is found in
what are the 3 requirements of a good index fossil?
- easily recognizable
- widely found
- short lived so that they are only found in one strata
what is radioactive dating?
a technique used to determine the age of a rock or fossil, the level of radioactive decay in the rock/fossil is measured to determine the age
what is biogeography?
the study of past and present geographical distribution of life on earth
what are homologous features?
features with similar structures but different functions derived from a common ancestor
what are analogous features?
features that are similar in function and appearance but do not have the same evolutionary origin
what are vestigial features?
structures that have no useful function/purpose in modern organisms but had use in ancestral form
what is embryology?
the embryos of different organisms exhibit similar stages of embryonic development
what is biochemistry?
if two species have similar patterns in portions of their DNA, this similarity indicates that they were most likely derived from a common ancestor
what is artificial selection?
the process of humans selecting a breeding individuals with the desired trait
what is speciation?
the formation of a new species due to gradual changes over a long period of time
what is adaptive radiation?
the diversification of a common ancestor into a variety of species
what are the two pathways of the formation of a new species?
- transformation
2. divergent evolution
what is transformation?
one species evolving into a different species
what are the two types of barriers that cause speciation?
- geographical
2. biological
what are geographical barriers?
physical barriers such as mountains or rivers
what are biological barriers?
behaviour that keeps two groups of the same species separate
what is allopatric speciation?
a three step process of a new species being formed
what are the three steps of allopatric speciation?
- population is separated by a physical or behavioural barrier
- natural selection works on the separate groups independently
- in time accumulated differences are so pronounced that two distinct species are formed
what is the theory of gradualism?
that evolution/speciation occurs at a slow, steady pace
what is the theory of punctuated equilibrium?
long periods of time in which little change occurs, followed by the abrupt appearance of many new species
what are the three types of adaptations?
behavioural, physiological and structural
