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
What is pollution?
it is the contamination of the environment by harmful substances that are produced by human activity
what are 4 common air pollutants?
- carbon dioxide
- methane
- carbon monoxide
- sulphur dioxide
what is the greenhouse effect?
it is when gasses absorb and re-emit some infrared radiation, which heats up the earth’s surface
is the natural greenhouse effect positive and why?
yes it is positive because it keeps our planet at liveable temperatures
which gases are absorbed by long wave IR radiation?
hint there are 5
- CARBON DIOXIE
- METHANE
- WATER VAPOUR
- nitrous oxide
- Chlorofluorocarbons
what happens to long wave IR radiation?
some is absorbed by greenhouse gases, and re-emitted back to the earth
what are the two biggest gases that human activities have lead to an increase in greenhouse effect in the atmosphere?
- carbon dioxide
- methane
how is the ‘bad’ greenhouse effect formed?
increase of gases -> more wave IR radiation absorbed and re-emitted -> enhanced greenhouse effect
what is the definition of global warming?
rise in the earth’s surface temperature
what causes the increase of carbon dioxide?
- the increase of burning fossil fuels
- increase of deforestation
why does deforestation cause an increase in carbon dioxide?
because less trees = less photosynthesis = less carbon dioxide removed from the atmosphere
what is the formula for carbon dioxide?
hydrocarbon + oxygen -> carbon dioxide + water
what is methane? and how is it produced?
it is a greenhouse gas and it is produced when microorganisms ferment larger organic molecules to release energy
what are the 3 sources of methane?
1) decomposition of waste in landfill sites by microorganisms
2) fermentation in the stomach of cattles by microorganisms
3) fermentation in rice fields by bacteria
what is the meaning of the word fermentation?
chemical breakdown of a substance by bacteria, yeast or other microorganisms
what are 3 impacts of global warming?
- polar ice caps would melt, sea levels would rise
- EXTREME WHEATHER
- DISRUPTION IN FOOD CHAINS
- change in ocean currents
- change in rainfall
- CHANGE IN MIGRATION PATTERNS
- increase in pests
what are people doing to reduce carbon dioxide levels?
- TRYING TO BURN LESS FOSSIL FUELS
- increasing use of alternative energy resources
- REDUCING DEFORESTATION
- encouraging people to walk/ cycle to shorter distances instead of drive
why is carbon important?
it is important because it is a component of all major biological molecules
what are the 5 organic compounds?
1) carbohydrates
2) lipids
3) proteins
4) DNA
5) vitamins
carbon dioxide is what type of molecule?
it is a inorganic molecule
what are 2 processes that involve carbon dioxide?
- photosynthesis
- respiration
what is the equation of photosynthesis?
6CO(squared) + 6H(squared)O + energy –> C6H12O6 + 6O(squared)
what is the equation for respiration?
C6H12O6 + 6O(squared) –> 6CO(squared) + 6H(squared)O + energy
what does photosynthesis do to carbon atoms?
How is carbon recycled?
it ‘fixes’ these atoms from carbon dioxide into organic compound, such as glucose and starch
what is assimilation?
the manufacture of new products in cells using the products of digestion
what does feeding and assimilation do to carbon atoms?
How is carbon recycled?
it passes the carbon atoms in organic compounds along food chains
what is the relation between carbon dioxide and respiration?
How is carbon recycled?
Respiration produces carbon dioxide from organic compounds as they are broken down to release energy
what is the relation between carbon dioxide and bacteria and fungi?
(How is carbon recycled?)
they break down organic compounds into simpler substances, and this is then released into the environment. When they respires they release carbon dioxide
what is the relationship between fossilisation and carbon dioxide?
(How is carbon recycled?)
when some living organisms don’t fully decay (because soil is too acid) fossil fuels are formed. They contain carbon from the living organisms
what is the relationship between combustion and carbon dioxide?
(How is carbon recycled?)
when fossil fuels are burnt, carbon dioxide is released into the atmosphere
what are the 7 ways carbon dioxide is recycled?
1) photosynthesis
2) feeding and assimilation
3) respiration
4) bacteria and fungi
5) fossilisation
6) combustion
7) ocean and rocks
what is the relationship between the ocean and rocks and carbon dioxide?
(How is carbon recycled?)
some carbon may also dissolve into oceans, or form carbonate rocks.
what is saprotrophic nutrition?
when dead organic matter is digested outside of the body by extracellular enzymes
what is digestion?
the break down of large, insoluble substances into smaller, soluble substances
how is carbon monoxide produced?
it is produced from the incomplete combustion of hydrocarbons
what is carbon monoxide?
it is an colourless, tasteless, and odourless, toxic silent killer.
how does carbon monoxide occurs?
it occurs when there is a limited amount of oxygen available.
what happens if inhale carbon monoxide?
if you inhale it, it will bind to haemoglobin in red blood cells. Meaning it cannot bind with oxygen = less oxygen reaching cells = organs stop working
what will happen to someone who has inhaled carbon monoxide for a period of time?
the person will loose consciousness and eventually die
how is sulfur dioxide formed?
it is formed when fossil fuels are burnt and as they contain sulfur impurities it react with oxygen in the air. This combines with water droplets in the air, causing sulfuric acid essentially causing acid rain.
how does nitrogen oxide gets formed?
it is formed when nitrogen and oxygen reacts at high temperature
what else other than sulfuric acid causes acid rain?
nitric acid
what are the 3 things that acid rain can cause?
1) death of conifer trees
2) make soil more acid
3) make lakes more acid
what happens if soil is too acid?
2 points need to be made
- root hairs become less effective at absorbing minerals, so slows tree growth.
- can also cause some ions to leach into lakes, killing fish
what are the 2 major pollutants of freshwater?
- sewage
- minerals from fertilisers
what is sewage?
wet waste from houses such as faeces and excrement and waste from factories and farms
what are the 2 problems caused if sewage enters waterways?
1) contains pathogenic bacteria, meaning danger to human health
2) reduces the level of oxygen dissolved in water meaning insects and fish die
how does sewage reduce oxygen?
it contains organic material, and these materials are broken down by aerobic bacteria and other microorganisms. When they are decomposed, they require more oxygen which ends up reducing oxygen in water
what is the definition eutrophication?
it is a process when an aquatic habitat receives large amounts of minerals. These minerals can be either natural or as a result o pollution
what are 2 minerals that usually enter soil by leaching?
nitrate and phosphate
what is leaching?
be removed from substance by a flow liquid (usually rainwater)
what does the excess of minerals cause?
it simulates the growth of plants, and and photosynthetic protoctists called algae.
Usually algae grow first, and increase in numbers rapidly.
what is algal bloom?
when algae grows and increase in numbers rapidly.
what are the 6 steps of eutrophication?
1) Increase in mineral ions
2) Algal bloom
3) Algae block the light from the sun, plants die
4) Algae die and decomposed by bacteria
5) Dead plants = less oxygen, more bacteria = less oxygen
6) Fish and other animals die.
what are things that help reduce eutrophication?
using organic fertilisers such as manure
why does using organic fertilisers help reduce eutrophication?
it helps because organic fertilisers are less soluble, so they are leached less quickly from the soil
carbon cycle, describe it
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