biology topic 7 Flashcards
why do animals have adaptations
enable them to survive the conditions in which they normally live.
what can adaptations be
behavioural (actions an organisms takes) - migration
structural (how an organism is built) – fur, hair
functional (how the organism works) – produces more or less
urine depending on water availability
give some features that would make an environment extreme
high temperature, pressure or salt concentration.
what are extremophiles
organisms adapted to surviving in extreme conditions as they have enzymes
adapted for survival in these extreme environments
what do Plants in a community or
habitat compete with each other for
Light
Space
Water and mineral ions from the soil
what do Animals in a community often compete with each other for
Food
Mates
Territory
what are abiotic factors
non-living factors
what are biotic factors
living factors
what are examples of abiotic factors that effect a community
Light Intensity
Temperature
Carbon dioxide levels for plants
Oxygen levels for aquatic animals
what are Biotic factors
which can affect a community
New predators
Low food availability
New pathogens
One species outcompeting
another
describe how you would do a quadrats practical
1) quadrat placed randomly in field - randomly generate a coordinate grid for the field
2) repeat 10 times
3) count number of organisms in each quadrat
4) use number of organisms, area of quadrant and area of field to estimate population
describe how you would do a transects practical
1) place a [30-m] tape measure across field
2) place quadrats next to the tape
3) count number of plants in every quadrat
4) repeat every 2 meters
increase precision - do it every metre
increase accuracy - repeat and calculate mean
describe the carbon cycle
1) plants photosynthesise
photosynthesis takes in CO2
plants use carbon dioxide to make carbohydrate / protein / fat / organic
compounds / named (e.g. enzymes / cellulose)
2) plants respire
animals respire
respiration releases CO2
3) plants and animals die
Microorganisms enzymes decay / decompose dead organisms
microorganisms respire to release CO2
4) Dead organisms form fossil fuels over millions of years
Fossil fuels burnt to release CO2
describe nitrogen recycling
Decay microorganisms release nitrate ions into the soil
nitrate ions taken in by roots
using active transport
to make amino acids / proteins
describe the water cycle
Water evaporates from the surface of the sea. Heat from the sun speeds up this process and so does the wind. Water vapour in the atmosphere cools down and condenses to form billions of tiny water droplets. Some of the droplets join together and fall as rain.
what are the best conditions for decay
Water
Oxygen
Warmth
Microorganisms called decomposers - these are bacteria or fungi.
describe the decay practical
Get 2 boiling tubes containing 20ml milk and 5cm3 lipase
Add five drops of the Cresol red and 5cm3 sodium carbonate solution to the milk tube. The solution
should be purple
Put both tubes in a water bath at 10⁰C
Wait until the contents reach the same temperature as the water bath.
Transfer 1cm3 of lipase from the ‘lipase’ tube to the ‘milk’ tube.
Immediately start the stopwatch
Stir the contents of the ‘milk’ boiling tube until the solution turns yellow.
Record the time taken for the colour to change to yellow, in seconds.
Repeat the investigation for different temperatures of water bath.
Explanation
Lipase breaks down fats in milk into glycerol and fatty ACIDS. Cresol red is purple in alkali, yellow in acid
what do Biogas generators do
anaerobically digest waste biological material and produce methane.
what can methane gas be used as
fule
what changes may occur due to environmental changes
seasonal e.g. migration of wildebeast
geographic e.g. coastal soil is more salty
caused by human interaction e.g.
introduction of a new predator to an area or buildings.
what is biodiversity
Biodiversity is the variety of all the different species of organisms on
Earth, or within an ecosystem.
why is biodiversity important
A high biodiversity ensures
the stability of ecosystems by
reducing the dependence of
one species on another for
food, shelter and the
maintenance of the physical
environment.
what is interdependence
Species in a community rely on each other for survival
give examples of interdependence
Many flowering plants rely on insects like bees or butterflies for pollination.
Animals or birds may carry plant
seeds away from the parent plant
to reduce competition.
what is A stable community
A stable community is one where all the species and environmental factors are in balance so that the population sizes remain fairly constant.
give an Example of a stable community
As the number of prey increase, so too do the number of predators.
As the number of predators increase, the number of prey decrease
Fewer prey means less food for predators so they too start to decrease
give examples of activities that have a negative effect on biodiversity
How we manage waste
How we use land
Deforestation
Global warming
what is water pollution
Sewage, artificial fertilisers and toxic
chemicals may enter lakes, rivers or the sea.
what is Eutrophication.
Algae in the water grow rapidly due to
fertiliser. Reduces amount of light
for plants at the bottom of the pond so they die.
No plants = no photosynthesis = no oxygen
Decay uses up oxygen so other living
organisms (fish) die as well.
what is Bioaccumulation
Bioaccumulation is the build-up of toxins along a food chain
what is the problem with burning fossil fuels
Fossil fuels may contain sulfur,
which reacts with oxygen to form
sulfur dioxide.
High concentrations can cause
breathing difficulties, react with
clouds to form acid rain
what human activities reduce the
amount of land available for other
animals and plants
Quarrying
Crop growing
Farming
building
waste dumping
what is Peat
Peat is made of plants in waterlogged bogs anaerobic conditions prevent decay.
what is peat sold as
Peat bogs is sold as compost or fuel.
what is the problem with the decay of burning of peat
Decay or burning of peat releases carbon dioxide into the atmosphere.
what is deforestation.
The removal of forest habitat
why does Large scale deforestation happen in tropical areas
Provide land for farming cattle for food
Provide land to grow crops for producing biofuel
what are some biological consequences of global warming
Changes in weather which include flooding and drought
Melting of ice caps and increase in sea levels
Habitat loss which can lead to species becoming extinct or critically endangered.
how can we Reduce the negative effects of humans on the environment
Reintroduction of field margins and hedgerows. Encourages diversity of wildlife as there is a variety of food.
Breeding programmes for
endangered species
Protection and regeneration
of rare habitats.
Reduction of deforestation
and carbon dioxide emissions
Recycling
resources
what are Trophic levels
Trophic levels are defined as the
feeding levels within an ecosystem.
Trophic levels can be represented by
numbers.
what are apex predators
Apex predators are carnivores
with no predator.
what are Producers
organisms which can make their food using sunlight (plants)
what are Primary consumers
organisms which eat producers (herbivores)
what are Secondary consumers
organisms which eat primary consumers (carnivores)
what are Tertiary consumers
organisms which eat secondary consumers (carnivores)
what is a herbivore
an animal that feeds on plants
what is a Carnivore
an animal that feeds on other animals
what is an omnivore
an animal that feeds on plants and animals
what is Biomass
Biomass is defined as the amount
of living material at each trophic
(feeding) level.
Pyramids of biomass can be
constructed to represent what
the relative amount of biomass in each
level of a food chain.
why are Pyramids of biomass a Pyramid shape
because the amount of biomass and
energy available at each trophic level
decreases.
what is the formula to Calculate the efficiency of biomass transfer
efficiency of biomass transfer = biomass transferred to next level / biomass available at previous level x 100
Producers transfer about what % of light energy for photosynthesis.
1%
what are there losses in biomass as its transferred through each tropic level
Not all ingested material (food taken in) is absorbed into the body. Some is egested as faeces.
Not all the absorbed material is used for new biomass. Some is lost as waste (carbon dioxide and water in respiration) and water and urea in urine.
Large amounts of glucose are used up in respiration and provide energy for movement, growth and keeping a constant body temperature.
what is Food security
having enough food to feed a
population.
what factors effect food security
Increasing birth rate
Changing diets
New pests and pathogens that affect farming e.g. Bird flu
Environmental changes due to global warming - famine if rains fail as
crops do not grow.
The cost of farming is high
Conflicts in parts of the world which affect the availability of food or
water.
describe what happens during intensive farming
Animals kept inside so less energy is lost in controlling body temperature
Kept enclosed so less energy required for movement
Both of which mean more energy is available for growth and less energy is
transferred to the environment
Give antibiotics to prevent them getting ill
how can the population of fish be maintained
- Regulate net size – larger holes mean smaller fish can escape
- Impose fishing quotas
- Limit fishing during breeding seasons
- Bans on discarding of fish
- Bans on fishing in certain areas
what is biotechnology used for
Modern biotechnology techniques enable large quantities of microorganisms to be cultured for food.
what is mycoprotein.
Mycoprotein is a protein-rich
food suitable for vegetarians.
describe how mycoprotein is produced
Fungus / Fusarium
Mixed with glucose
in aerobic conditions or in presence of oxygen
mycoprotein is harvested / purified
Genetically modified crops (GM) can be used to provide what
can be used to provide more food or food
with an improved nutritional value.
Advantages of genetically modified crops
higher yield
less use of pesticides
More nutritious food to supplement diet
Crops can survive harsher environmental conditions
disadvantages of genetically modified crops
uncertain about effects on health
bee population might decrease
might breed with wild plants
seeds only from one manufacturer
