definitely in exam mix! Flashcards
What is homeostasis?
the regulation of internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
What 3 things does homeostasis control?
- blood glucose concentration
- body temperature
- water levels
what do receptors do and what is one example?
- detect stimuli (a change in environment)
- skin cells
what do coordination centres do?
name 3 coordination centres
- receive and process information from the receptors
- the brain, spinal cord, pancreas
what do effectors do?
what 2 things in the body are effectors?
bring about responses which optimise levels
muscles and glands
how did Carl Linnaeus classify animals in the 1700’s?
Kingdom Phylum Class Order Family Genus Species
Homo sapiens is a binomial name what 2 classifications does it include
Genus - homo
Species- sapiens
Why has classification improved?
2 marks
-improved microscope technology
(with more detail in internal structures)
- better understanding of biochemical processes (DNA)
(because of chemical analysis)
How do we classify now (Carl Woese’s system)
Into domains There are 3 types: - Archaea (primitive bacteria) - Bacteria -Eukaryota ( protists, fungi, animals, plants, kingdom, phylum)
biotic factors
the living parts of an environment that have a major impact on the other living parts
abiotic factors
non-living parts of the environment that affect the living parts
List 4 biotic factors
- competition
- predators
- pathogens
- availability of food
List 6 abiotic factors
- light intensity
- temperature
- soil pH
- moisture levels
- wind intensity
- carbon dioxide levels
define adaptations
features of an organism which allows them to survive, compete, be successful
list 4 things plants compete for
- water
- nutrients
- space
- sunlight
list 5 things animals compete for
- mates
- food
- territory
- water
- shelter
What 3 things can adaptations be broken down into
- Structural
- Behavioural
- Functional
Are these functional, structural, behavioural??
- sweating
- feet with large surface area
- sharp teeth
- migrating to warmer climates
- increasing metabolic rate
- penguins huddling together
- functional
- structural
- structural
- behavioural
- functional
- behavioural
define ecosystem
the interaction of a community of biotic factors with abiotic factors of their environment
define species
group of organisms which can reproduce to produce fertile offspring
define interdependence
1 organism relies on another
e.g: for food
what are the 6 parts of a food web
- producer primary consumer - secondary consumer - tertiary consumer - apex predator - decomposer
define intraspecific
competition between individuals of the same species
define interspecific
competition between individuals of different species
define habitat
place where an organism lives
define population
all of the organisms of a particular species that live in that habitat
define community
all the populations of different species that live together in a habitat
define competition
an interaction between organisms or species in which they both try to use the same limited resources
define stable community
all the species and environmental factors are in balance so that population sizes remain fairly constant
Explain the carbon cycle
- plants and animals release CO2 when we respire
- plants take in CO2 during photosynthesis
- when plants and animals die during the decay process they are eaten by micro organisms which releases the carbon in their cells
- animals eat plants releasing the carbon they stored
What are the 3 kinds of pollution and what are their sources?
water - from sewage, fertiliser, toxic chemicals
air - from smoke, acidic gases
land - landfill, toxic chemicals
What affects is an increased global population having?
increased global population
increased use of earth’s resource
therefore increased waste material
as a result = increased pollution
define water pollution
the pollution of water by sewage, chemicals, fertilisers
define air pollution
the pollution of air by burning fossil fuels, cattle farming (when cows fart they release methane)
define land pollution
the pollution of land by humans by building on land, modifying environments for agriculture, extracting minerals
what is global warming
this increase in earth’s temperature leads to climate change
what is an increase in greenhouse gases caused by?
- cattle farming (methane)
- burning fossil fuels and deforestation (carbon dioxide)
What is deforestation and what are the implications of it?
- large scale removal of forests
so less CO2 is absorbed
but also when these trees are burnt it releases CO2
it also causes mass destruction of habitat having a negative impact on biodiversity
What are the consequences of global warming?
- droughts
- flooding (due to increased sea levels because of melting ice caps)
_ decreased biodiversity ( due to habitat loss and this puts more animals at risk of extinction) - increased diseases (malaria- will be hotter so these mosquitoes may migrate to here and thrive in our climate)
define deforestation
large scale removal of forests
why do we deforest?
- clear land for farming
(raise cattle, plant other crops, biofuels) - logging
(use wood to build things, burn for fuel) - mining
(quarrying)
the problems of deforestation
- more carbon dioxide in the atmosphere (which contributes to global warming)
- burn the trees
(releases more carbon dioxide but also the smoke can suffocate animals and pollute towns - reduces biodiversity in area (puts animals at risk of extinction)
what is the soil like in peat bogs?
acidic and waterlogged
when peat bogs are drained for farmland what happens to the soil
because there is now no water so air and oxygen can go into the peat allowing micro-organisms to respire aerobically and decompose the organic matter which releases carbon dioxide into the atmosphere which is a greenhouse gas and contributes to global warming
what do we use peat for? (2 marks)
- fuel
- compost in our gardens
Do peat bogs decay organic matter more or less than normal soils?
less
as the bars get smaller in a biomass pyramid what is happening to the total mass of the organisms ?
it is decreasing
what do pyramids of biomass show?
the biomass of each tropic level in a food chain
why is only 10% of the biomass and energy passed on? (3 marks)
- organisms don’t eat every part
-the bit they do eat might not be absorbed and may be egested as faeces - some absorbed material is lost as waste like urea in urine and carbon dioxide + water in respiration
- most of the nutrients animals do absorb are used to release energy through respiration (- large amounts of glucose are lost during respiration)
(biomass is released as waste products e.g: carbon dioxide and urea)
how to calculate the efficiency of biomass transfer
efficiency= biomass transferred to next level
——————————————————-
biomass available at the previous level
x100
define a stable community
all the species environmental factors are balanced so population sizes remain fairly constant
define interdependence
if one species is removed it will affect the whole community
explain the water cycle (6 marks)
- the sun heats up the surface of the water causing it to evaporate ( from rivers, oceans)
- the transpiration from plants releases water vapour into the air
- the moist air cools as it rises causing it to condense forming cumulonimbus clouds
- as the water droplets in the clouds get bigger and heavier they start to fall as rain, hail, sleet, snow ( the 4 forms of precipitation)
what do decomposers and detritivores do?
decompose the dead animal and plant matter in the environment
What do the arrows in a food chain show?
The transfer of energy & biomass
define extremophiles (2 marks)
microorganisms like archaea and bacteria that are adapted to live in extreme environments where there is high temperature, pressure, or salt concentration
