Unit 3 Life On Earth End Unit Check Test Flashcards
Help study for end of unit check test
Define the terms
biodiversity, ecosystem, community, habitat, population, niche
Biodiversity: is the range of species present in an ecosystem
Ecosystem: is all of the organism living in a particular habitat
Community: refers to all the living organisms in a habitat or ecosystem
Habitat: a place where organisms live
Population: is the total number of one type of species in an ecosystem
Niche: is the role that an organism plays within a community
What are the definitions of producer, consumer, herbivore, carnivore, omnivore, predator, prey
Producer: is a green plant which can make it’s own food from sunlight
Consumer: a animal that gains its energy by consuming other organisms
Herbivore: a animal that only eats plants
Carnivore: a animal that only eats other animals
Omnivore: a animal that eats both plants and animals
Predator: a animals that hunts and kills prey
Prey: a animal that is hunted and killed by another animal
When does competition in an ecosystem occur
Competition in an ecosystem occurs when their is a shortage of recources
What are examples of resources that are fought for during competition
Plants: light, nutrient, water and space
animals: food, shelter, water and mates
what are the TWO DIFFERENT types of COMPETITION.
Interspecific competition occurs amongst individuals of different species for one or a few of resources they require
Intraspecific competition occurs amongs individuals of the same species and is for all the resources they require
which competition is more intense
intraspecific is more intense as you will be competing for identical things than compared to interspecific which only some resources may be the same
what is a food chain
a food chain is a diagram that shows how energy moves from one organism to another in an ecosystem
energy moves along the food chain when one oprganism eats another
what is the order of a food chain
The food chain starts with a producer and is then consumed by the primary consumer (first consumer in the chain).
The second consumer eats the first consumer and is called the secondary consumer
what do the arrows represent in the food chain
the arrows in a food chain represent the direction of the energy flow
does the energy flow in seprate indipendent food chains
no it doesn’t it goes through many
interlocking and interdependent food cahins this is called a food web
what can you see in the food webs
you can see the interactions between different organisms like how mice and grasshoppers primary consumer eat grains a producer which are then eaten by the owls a secondary consumer
what happens to the energy when it is passed from one level to the next
energy is lossed when it is passed on from one level to the next
why is the enrgy in the food chain lost for and what is the energy not being lossed used for
the enrgy in the food chain being lossed is in movment, heat and undigested material the enrgy not being lossed is used for growth
what happens to a pyramid of numbers is a single producer is present in the pyramid of numbers
it becomes a irregular shape where it becomes smaller on the bottom section
what happens, to the pyramid of numbers if parasites are present
if poarasites are present then the sections representing the parasites become alot bigger than the middle and bottom sections
what is the energy of pyramids measured in
kJ/m2/year
what is a biotic factor
a biotic factor is a living factor that can influence the population of organisms like competition for resources, disease, food availability, grazing and predation.
what happens when predation on prey increases
if predation on prey increases the opulation of prey will decrease.
what happens when grazing is at a low level.
if grazing is at a low level it decreases biodiversity as the dominant plants will outcompete the other species
what happens if grazing is at a high level
if grazing is at a low level biodiversity will increase because dominant polants will be kept in check allowing less dominant plants to grow
what happens if grazing is at a very high level
if garzing is at a very low level biodiversity will decrease as all plants will be eaten and nothing wll be given a chance to grow.
what is a abiotic factor
a abiotic factor is a non-=living factor that can affect the distribution and abundance of plants like light intensity, moisture, pH and temprature
why is light intensity important
light intensity is important because it is required for photosynthesis and light intensity affects the rate of photosynthesis
high light intensity=higher rate of photosynthesis
low light intensity= lower rate of photosynthesis
what does a plant use moisture for
a plant uses moisture for photosynthesis so a high moisture level will increase the rate of photosynthesis
and it helps keep cells in a turgid condition
lack of moisture will result in slow rate of photosynthesis and wilting
what can be a source of error when measuring abiotic factors
sources of error include
soil moisture not wiping or cleaning inbetween readings
light intensity shading the sensor when taking a reading
pH not wipiong the probe clean inbetween each reading
Temprature the liquid in the thermometer should be given time to nsettle when taking a reading and the probe should also be wiped clean inbetween each reading
one other source of error for all factors is not repeating the experiment to ensure a reprensentative sample is collected
how do you minimize sources of errors using a quadrat
You can minimize sources of errors by throwing the quadrat randomly and count the species accuratley make a rule to decide what do with plant that fall partly in or out of the quadrat and adequate replication to collect a representitive sample and having a good amount of knowledge to help with identification
what are pitfall traps used for
pitfall traps are used to measure the population of ground-living invertebrates
how do setup a pitfall trap
a pitfall trap is setup by getting a pot anfd putting small water draining holes so the invertabrates don die from downing from rain water whch when put inn the ground it’s level with the ground and a raised lid is placed on top to stop predatory birds from eating the invertabartes.
what are the six human influences on biodiversity
the six human influences on biodiversity are air pollution, water pollution, habitat destruction, deforestation, desertification and biodiversity
what are indicator species
indicator species are species that by being presence or absent indicate enviromental quality or levels of pollution
describe the first process of photosynthesis
the first process of photosynthesis light reactions light from the sun is trapped by the chlorophyll by the chloroplsts and is then converted to chemical energy which is used to generate ATP the water is split to create hydrogen and oxygen which diffuses from the cell and the ATP and hydrogen are passed on to stage 2
describe the procees of second stage of photosynthesis
the second stage of photosynthesis called carbon fixation and is a series of enzyme-controlled reactions which joins the hydrogewn and carbon dioxide together using the ATP to producer sugar (gluclose)
name three fates of the gluclose
three fates of gluclose are that can be turned into starch for storage or could mde in to cellulose and could be used for respiration
what chemical is used to test for starch to check if photosynthesis has occurred
iodine
state three limiting factors in photosynthesis
light intensity, carbon dioxideconcentration and temprature
what is a limiting factor
a limiting factor is a factor that is required for photosynthesis
what happens to the rate of photosynthesis when the limiting factors are in short supply
when these factors are in short supply they will slow down the rate of photosynthesis
why does a increase in population require a increase in food yeild
a increase in food yeild is required for a increase in population to keep the increase in population alive
what are nitrates used for
nitrates are used for the production amino acids
explain what amino acids are used for
amino acids are used for the produce plant proteins
why do aniamls consume other animals or plants
animals consume other animals or plants to obtain amino acids for protein synthesis
what happens when extra fertilisers end up in water
when extra fertilisers end up in water it results in a algal bloom algal blooms result in blockling light which kills aquatic plants these dead plants and algae become food for bacteria which then increases greatly in number. the bacteria then use up large amounts of oxygen reducing availibility for other organisms. this results in the death of other species livin in the water reducing biodiversity
what can be used to reduce the use of fertilisers
geneticall modifide crops can be used to reduce the use of fertiliser
what are the negative impacts of spraying the pesticides onto crops
one negative impact of spraying pesticides onton crops is that the pesticides don’t break down quickly so the pesticide can slowly build up a in living organisms after many organisms are eaten by one individual this called bioaccumulation
describe the term bioaccumulation
bioaccumlation is when pesticides slowly build up after being p[ased along the food chain and as the food chains go further the toxcity of the pesticide increases
what is the impact of pesticides being passed along the food chains
when the pesticide gets passed along the food chain it slowly becomes more potent to the point where it eventually kills one of the organism that eats the other organism
what are two other alternatives to the use of pesticides
genetically modified crops can be used as a alternative to pesticides because when a pest attaches to a genetically modifide crop it can release a toxic chemical that can kill the pest one other altenative can be to use biological control
which is when you use the natural predator or pathogen to control it’s population
give two examples of biological control
using the virus myxomatosis to kill rabbits and using lady birds to kill aphids
define the term mutation
mutation is a random change to genetic material
what are muations the only source of
mutations are the only source of new alleles
what are mutations
mutations are spontaneous
what does the varation in population make possible
the varation in population makes evolution possible
mutations may be neutral, confer an advantage or a disadvantage to survival explain how a mutation can confer an advantage to an individual
a mutation can confer an advantage because they will help make the organism better adapted to their surroundings
what is an adaptation
is an inherted charcteristic that makes a organism well suited to survive it’s environment or niche
name two factors that increase the rate of mutations
two factors that increase the rate of mutations are radiation and some chemicals
what is a selection pressure
selection pressures are factrors that affect an organisms ability to survive in a certain environment
give three examples of selection pressures
finding food and predation and disease
describe the process of natural selection
during the process of natural selection the best adapted individuals in a mpopulation survive and reproduce passing on the more favouable alleles that pass on the selective advantage since these alleles are passed onto the next generation they increase in frequency within the population
what is passed on during natural selection
favourable alleles
what happens to the frequency of the alleles which confer the selective advantage
they increase in frequency within the population
what is speciation
the speciation is the form of newspecies from a common ancestor
what is the function of an isolation barrier in speciation
a isolation barrier prevents the exchange of genes between individuals of seperate populations
when does speciation occur
speciation occurs when a part of the population becomes isolated by a isloation barrier
what are the different types of isolation barriers
geographical which are rivers mountaibns and oceans
ecological which can be pH, salinity or different habitats
behavioural which include mating rituals and signals
explain why natural selection selects for different mutations in each group
natural selection selects for different mutations because they each face different pressures
what step could be taken to see if the two populations have become different species
the step that could be taken is to see if they produce fertile young
