Biology test Flashcards
various types of organisms that live in the same suburban backyard. these organisms together make up…?
a community
Biotic factors are the living components of an ecosystem. They are sorted into three groups:…?
producers or autotrophs
consumers or heterotrophs
decomposers or detritivores.
a location where primary succession cannot occur?
a forest that has been destroyed by fire
homo erectus and homo sapiens belong to the…?
same genus but different species
genetic diversity is important as it ensures that a species can…? (3)
avoid inbreeding with members of the same species
resist disease
survive when the conditions of its environment are changed
adaptions? (3)
behavioural
structural
physiological
natural source of carbon dioxide emissions? (2)
plant/animal respiration
volcanic combustion
consequence of increasing carbon dioxide concentrations in the atmosphere?
enhanced green house effect
difference between habitat destruction and habitat fragmentation?
habitat destruction is the complete removal and deconstruction of the habitat/ecosystem that organisms occupy. habitat fragmentation is when the natural ecosystem is broken up into isolated patches.
why polar bear is keystone species?
it applies to the control of the population of seals, whales, walrus, reindeer, rodents, seabirds, fish, and vegetation in its ecosystem. this prevents those population sizes from increasing to unsustainable levels which could disrupt the food web.
community?
the populations of different species interacting in the same place at the same time.
how can re-establishment of climax community occur after a fire?
climax community= An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.
there is existing soil after disturbance, colonising plant species can quickly grow.
trophic level of ecosystem is removed? what is this called?
trophic cascade
consequences of ecosystem without sea otters? (keystone species)
the sea urchin population will increase. there is increased predation of kelp (producers) to the point where it is completely removed from the ecosystem. this results in the collapse of other trophic levels and chains that rely on kelp for energy production.
define structural adaption?
physical characteristics that an organism possesses which increase its chance of survival and reproduction.
define behavioural adaptions?
behaviours exhibited by an organism that increases its chance of survival and reproduction.
define physiological adaptions?
metabolic processes that an organism possesses which increase its chance of survival and reproduction.
needs fulfilled by adaptions that enable an animal to survive in its environment? (3)
hair in ears and eyelashes - prevent debris from getting into ears and eyes.
wings - to fly
hormone & electrochemical signals to generate the desired response
Abiotic factors?
non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. such as: Sunlight Soil Water Atmospheric and Dissolved Gases Temperature Fire
population?
The term “population” surrounds a group of organisms of a single species that can interbreed and live at the same time in the same environment.
species?
A species is often defined as a group of organisms that can reproduce naturally with one another and create fertile offspring.
producer?
Producers are organisms that make their own food; they are also known as autotrophs. They get energy from chemicals or the sun, and with the help of water, convert that energy into useable energy in the form of sugar, or food. The most common example of a producer are plants.
consumers?
Consumers are organisms that need to eat to obtain energy.
decomposer?
They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.
the trophic levels?
1: Plants and algae make their own food and are called producers.
2: Herbivores eat plants and are called primary consumers.
3: Carnivores that eat herbivores are called secondary consumers.
4: Carnivores that eat other carnivores are called tertiary consumers.
arrows in food chain
show the direction in which energy and nutrients flow
10% rule
On average, only about 10 percent of energy stored as biomass in a trophic level is passed from one level to the next.
why start with producer?
because some organism has to be able to produce energy from its environment to get the chain/web started.
keys points of natural selection.
Variation, Inheritance, Selection, Time and Adaptation.
how an original (ancestral) population may develop into 2 different species.
These changes might occur by natural selection or by random chance (i.e., genetic drift), and in both cases result in reproductive isolation.
how an original (ancestral) population may develop into 2 different species.
These changes might occur by natural selection or by random chance (i.e., genetic drift), and in both cases result in reproductive isolation.
