Populations In Ecosystems Flashcards
(39 cards)
define ecosystem
all the organisms living in a community plus all the abiotic conditions in the area in which they live
define community
a group of interacting populations of different species living in the same place at the same time
define population
a group of organisms belonging to the same species found in the same area at the same time and potentially able to interbreed
define habitat
the environment in which an organism or population of organisms usually live
define biotic
the living features of an ecosystem e.g. the presence of predators or food
define abiotic
the non-living features of an ecosystem e.g. temperature and the soil
define niche
the role of a species within its habitat e.g. what it eats, when and where it feeds
explain competitive exclusion
if 2 species try to occupy the same niche, there will be competition. one species will be more successful and survive and reproduce
define adaptation and whats it caused by?
-a characteristic that members of a species have that increase their chance of survival and reproduction
-caused by random and spontaneous mutations
define natural selection
when adaptations become more common in a population increasing allele frequency
define carrying capacity
the max population size that can remain sustainable in an ecosystem
give an example on the effect of abiotic factors on plants
a plant will grow much quicker if there is a higher temperature, higher light intensity, water and space available
how might a abiotic factor of colder temp effect mammals?
-having the use a lot of energy to maintain the correct body temperature
-so less energy available for growth so slower growth
-less reproduction
-so population size will decrease
what are the 3 main types of biotic effects that can influence population?
- interspecific competition
- intraspecific competition
- predation
describe interspecific competition
-competition that occurs between different species
-can be competing to occupy the same niche
-one species will have a competitive advantage = competitive exclusion principle
(inter= think intergalactic (outside different) from beastie boys)
describe intraspecific competition
-competition between members of the same species
-causes fluctuations in population size around the carrying capacity = cyclical pattern
-as population increase, there are less resources for a larger population
-more intraspecific competition so now less food/energy for growth and reproduction
-population decreases so recourses increase
-less intraspecific competition
-more food/energy for growth and population so population increases
describe predation on population size
-predation is where a predator kills and eats its prey.
-prey and predator pop sizes are inter-linked
-the relationship between them creates a selection pressure
-means those members of the species that are better adapted to hide or escape from predators are more likely to survive and reproduce
why will predators never have higher population than prey?
biomass is lost so less energy to grow and reproduce
what’s the advantage in knowing cyclical predation patterns?
carry out research at a more advantaged time when populations are higher
why do we use logs?
-compare values with a very large range
-diff to plot on y axis
-to find the original value
-values in order of magnitude not numbers
what does the log10 number tell you?
how many times 10 has been multiplied by itself to give that value
factors 2 effecting bacteria growth
food and space available
whats a broth culture?
a liquid broth containing bacteria
whats a liquid broth?
a liquid containing nutrients a bacteria needs to grow
