Module 3 and module 4 Flashcards
habitat
a place where an organism lives
population
all members of a single species living together in a habitat
community
all the populations of different organisms living together in a habitat
ecosystem
a community of animals, plants and organisms together including the physical environment
abiotic factors
non-living features of an environment
biotic factors
living features of an environment
terrestrial ecosystems include
desert, grassland, tropical rainforest, woodland
aquatic ecosystems
saltwater, marine
biotic factors include
food availability, predators, decomposers, diseases, availability of mates
abiotic factors include
water availability, temperature, soil pH, wind, humidity, altitude, light intensity
selection pressures
things that push an organism to survive.
a change in environment results in
limited resources, therefore individuals compete for resources
extremophiles
organisms that live in extreme environments
population
a group of organisms of the same species living in an area at the same time
ecology
the study of interrelationships of organisms with eachother and the environment which in turn determines their distribution and abundance.
The three interactions between species includes
predation, competition and symbiotic relationships
predation
prey relationship where predator obtains food by killing and eating
competition
when two or more organism use the same resources (directly)
symbiotic relationship
interaction between two organisms in a close relationship that is beneficial to one of them
obligate
when one species relies entirely on another
facultative
a non-essential but beneficial relationship between species
different types of symbiotic relationships
mutualism, commenalism, parasitism
mutualism
both species in a relationship benefit eg. clownfish and anemone, coral and algae
commensalism
one species benefits and the other is unaffected eg. barnacles and whales
parasitism
one species benefits and the other suffers non-lethal damage (usually) eg. mosquito, tape worm
different types of competition
intraspecific, interspecific
intraspecific
between the same species
interspecific
between different species which can lead to evolution of one species in response to another
allelopathy
the production of biomolecules by one plant which can be beneficial/detrimental to another plant.
niche
part of an ecosystem that an organism contributes or uses including abiotic and biotic factors.
photosynthesis
occurs in two phases: the light dependent and light independent phase
light dependent phase (light phase)
occurs in the grana of the chloroplast. Water is split in the presence of solar energy and chlorophyll into hydrogen and oxygen, also producing ATP.
water ——} hydrogen ions + oxygen + ATP
light independent phase (dark phase AKA calvin cycle)
occurs in the stroma of the chloroplast which produces glucose, water, and ADP which doesn’t require solar energy. ATP made in stage one provides energy from dark reactions.
hydrogen ions + ATP + carbon dio. –} glucose + water + ADP
the two major biochemical processes that cells carry out are
photosynthesis and cellular respiration
importance of energy
energy is required for all essential life processes to take place. All cells use glucose as the primary source of energy to drive chemical reactions in cells.
how glucose can be broken down
aerobic respiration in the presence of oxygen where 36 ATP’s are produced and is more efficient. Anaerobic respiration without the presence of oxygen where only 2 ATP’s are produced.
two types of anaerobic respiration
lactic acid and alcoholic fermentation
cellular respiration
Glucose + oxygen —-} carbon dio. + water + ATP
distribution
the area in which an organism is found
abundance
the number of given individuals of species in an area
the most suitable sampling techniques for an organism depends on
- type of organism (plant/animal, fast/slow moving, robust/delicate)
- environment it lives (aquatic, terrestrial)
- type of distribution (regular/clumped)
transects
techniques used to measure the distribution of species in an ecosystem commonly used to give an idea of variation. It is a narrow strip that crosses the entire area being studied, from one side to another.
Single transect lines may have quadrats placed and counted at regular intervals along the line
belt transect
two transect lines made to create a strip in which organisms are counted.
plant abundance
measured by counting the number of organisms in a small area to be expressed as a percentage. If organisms are too numerous and scattered, percentage cover isn’t suitable
quadrats
A randomly chosen square plot of land (usually 1x1) to determine the percentage of vegetation and animals occurring within the marked area. Direct counts or percentage cover is made within the quadrat.
capture-recapture method
may be suitable for moving animals. The steps include:
1. sample of species is captured, counted, tagged/marked, and then released
2. mixing time is allowed with the population
3. recapture and count the second sample, specifically count the number of tagged animals in the recaptured sample
5. abundance is calculated using the following formula
abundance= number captured*no. recaptured/no. marked in capture
sampling techniques
transects, plant abundance, capture-recapture
food chains
show energy flow within a system. They start with a plant that is consumed by an animal and usually have 3-5 species.
producer — primary consumer/1st order consumer —etc..
decomposers
things that cause the breaking down or rotting away. They can include fungus and bacteria, as well as earthworms
producers
produce their own food using carbon dioxide and water
consumers
eat other living things (can be herbivores, carnivores, omni)
food web
a series of food chains all connected to each other. Plants are eaten by a variety of consumer animals and then those animals may be eaten by a variety of different carnivores.
Prickly Pear: distribution
was introduced to Australia because the conchineal dye industry was to be started in Australia and is considered to be a pest because it is:
- easily propagated
- very invasive
how the Prickly Pear was removed
The Prickly Pear Travelling Commission discovered that the cactoblastis moth larvae could eat through hectares of prickly pear-infected land. The lack of biodiversity in the prickly pear population allowed for the larvae to eat through the plants before they could adapt.
Cane Toads: changing populations
introduced in 1935 to control pest beetle populations in Queensland’s sugar cane crops. Characteristics which allow for their thriving population as a pest includes:
- can lay 30 000 eggs at one which hatch in 2-3 days
- feed mainly at night
- no known predators
how Cane Toads have caused native species to evolve in response
Red Bellied Black Snake: their heads are getting smaller because larger cane toads produce more poison. Snakes with larger heads would die because they ate larger ones.
Quolls (birds): Quoll populations have reduced because they have eaten the toads, but the Northern Quolls are toad adverse which is advantageous as it increases their chance of survival. Scientists have used the Quolls characteristic of prudence to achieve toad avoidance
Theory of Evolution by Natural Selection
Darwin observed small ground finches on the Galapagos island and collected some to bring back to England. Darwin noticed that the finches’ beaks were different and wondered if they originated from an original population in Mainland South America that had changed.
Darwin’s evidence for his theory
- some South American finches had landed in the Galapagos
- finches had naturally occurring variation in population
- descendants of these birds populated other islands with different environmental conditions
- depending on the conditions, some birds thrived and reproduced, which others died out
Today, his theory is known as ‘survival of the fittest’
five principles of Darwin’s theory
- adaptations (thumb)
- movement related to gene flow (pointer finger)
- mutation (middle finger)
- mating (ring finger)
- shrinking population (pinky finger)
