Ecology and the Environment Flashcards
what is an ecosystem?
It is all the living and no-living organisms in a particular area
can ecosystems have ecosystems inside them?
give an example
yes, like rivers on forests
what are producers?
plants or algae which photosynthesise to produce food
what are consumers?
animals that eat (consume) other plants or other animals
what are decomposers?
organisms that break down (decay) dead material and recycle nutrients
what is the physical environment?
non biological components, such as water and soil
what is a habitat?
a place where an organism lives
what is a population?
all the organisms of a particular species found in a ecosystem at a certain time
what is a community?
the population of all species found in an ecosystem at a given time
what are the names of the two factors that influence the distribution of organisms and population sizes in an ecosystem?
abiotic and biotic
What are biotic factors?
Give 3 examples
Biological factors (living)
examples:
- DISEASE
- presence of pollinating insects
- FOOD availability
- parasitism
- predation
- COMPETITION
What are abiotic factors?
Give 3 examples
Physical or chemical factors (non living) examples: - temperature - light intensity - soil/water pH - pollution - oxygen - mineral availability
what are ecosystems continuously doing with each other and their physical environment?
(hint: there are 3 points)
- feeding among other organisms.
- competition among other organisms.
- interactions between organisms and the environment.
what is having a stable community mean?
it means that there is a large range of correct biotic and abiotic factors.
what happens if a factor within a stable community changes?
there will be a change in population size or distribution
what do animals compete for?
Give 3 examples
- food
- mates
- shelter
- nesting sites
what do plants compete for?
Give 3 examples
- light
- water
- mineral ions
- carbon dioxide
how are organisms adapted to survive in certain habitats?
their structure is suited to it. Also, it depends on the habitat and organism
example question:
How is a polar bear adapted to survive in its habitat?
Give 3 examples
- white fur
- large paws
- large body mass
- layer of blubber
what is sampling?
it is a technique that ecologists use to calculate how many organisms are living in a habitat.
what is a sample?
a smaller representative part of the population.
how do you take a sample?
you use a piece of equipment called quadrat
how do you calculate the area of a quadrat?
width x length
ex.
- 0.5 x 0.5 = 25 cm(squared)
- 1 x 1 = 1 m(squared)
where do you place your quadrat when taking a sample? and why?
the quadrat must be placed randomly. This is so that you avoid bias and ensure validity
Explain the step by step method of sampling
there are 4 points to be made
1) place 2 measuring tapes at right angles
2) use a random number generator to generate a set of coordinates
3) walk along for the first number, and up for the second and place the quadrat
4) count number of x things.
5) repeat this process at least 10 times to improve reliability.
how do you find the average of something?
sum up all numbers and divide by the number of added numbers. ex. 2, 3, 3, 5, 7, 10 added together = 30 30/ 6 = 5
what calculation do you do to calculate the average number of x in the field?
important facts!!
area of field = 30
3 dandelion average in 1 square
ex.
area of field: 6 x 5 = 30
3 dandelion average in 1 square -> 3 x 30 = 90
what is a food chain?
it is a simple way of showing feeding relationships within an ecosystem
what are trophic levels?
it is different stages within a food chain
what are the four stages of a food chain?
- producer
- primary consumer
- secondary consumer
- tertiary consumer
what is a producer?
2 points
- it is the start of a food chain
- it uses photosynthesis to produce food
what is a primary consumer?
2 points
- eats the producer
- is a herbivore
What is a secondary consumer?
2 points
- eats the primary consumer
- it is a carnivore
what is a tertiary consumer?
3 points
- eats the second consumer
- carnivore
- nothing else eats it
what do the arrows in a food chain stand for and what does the movement of the arrow show?
- it stand for ‘is eaten by’
- shows the movement of energy from one organism to another as a result of eating
what is the name of the group of fungi or bacteria that can be added to food chains?
decomposers
what are food webs?
they are interrelationships that exist between food chains and an ecosystem
how does change in a population of an organisms in the food web might affect other?
other organisms may increase or decrease or stay the same
ex.
if the population of krill decreases, so does the population of blue whales