Download OCR Biology B2 - Wey Valley School

OCR Biology Module B2 UNDERSTANDING OUR ENVIRONMENT
B2a Ecology in our School Grounds
Collecting methods
Sampling
Identification keys
Ecosystem
Habitat
Population
Community
Biodiversity
Ecosystem – natural/artificial
Undiscovered species
pooter/nets/pit-fall trap/quadrat
to estimate population/size; Limits on method – accuracy/unrepresentative
use keys to identify plants and animals
made up of habitat (non-living) and the community (all the organisms) living there
place where an organism lives
group of individuals of one species living in an area
all the organisms that live in the same area and interact with one another
the number of species of organism in a particular ecosystem
(lake/fish farm) differences in biodiversity because of use of – weed killers/pesticides/fertilisers
some ecosystems (ocean depths) are still unexplored, with possible undiscovered new species.
B2b Grouping Organisms
Plants – characteristics
Animals
Fungi
Vertebrates/invertebrates
Fish
Amphibians
Reptiles
Birds
Mammals
Problem classification
Species definition
Similar species
Very different species
Hybrid
Binomial naming
chloroplasts, ability to make own food, more spreading
movement, cannot make own food, more compact for movement
neither plant nor animal; so is another kingdom
backbone or not
wet scales, gills
moist permeable skin
dry scales
feathers, beak
fur, produce milk
Euglena (animal and plant features). Archaeopteryx (bird and reptile features)
organisms of the same species are capable of interbreeding to produce fertile offspring.
may look similar when they live in similar types of habitats; share recent ancestors
may look similar because of similar adaptations (dolphin/shark)
two different (but close) species can breed to make a hybrid; hybrid offspring are infertile (a mule)
each species has a two part (Latin) name
B2c The Food Factory
Photosynthesis
Glucose
Starch
Cellulose
Proteins
Fats/oils
Photosynthesis – increased by
Limiting factors
Plant respiration
6CO2 + 6H2O→C6H12O6 + 6O2 [needs light energy and chlorophyll)
made in photosynthesis – transported as soluble sugars but stored as starch; converted to other substances
used for storage because insoluble (compact/not draw in water)
cell wall
growth/repair
storage
more light/higher temperature/more CO2
explain graph – horizontal line = another factor is limiting the increase in photosynthesis
respiration = all the time; gas exchange – day (CO2 in =photosyn. + resp.); night (CO2 out = just resp.)
B2d Compete or Die
Animal competition
Plant competition
Ecological niche
Predator/prey
Mutualism [win-win]
Nitrogen-fixing bacteria
Parasitism [win-lose]
for limited resources – food/water/shelter/mates
for limited resources – light/water/minerals
role/type of organism in an ecosystem; close competitors fight for the same niche
population numbers cycle in regular up and down patterns
two different species in close relationship; both gain; Nitrogen-fixing bacteria/cleaner species
in nodules of leguminous plants. Bacteria gains sugars. Plants gain nitrates.
two different species in close relationship; parasite live on/in host; host suffers; fleas/tapeworms
B2e Adapt to Fit
Adaptations
Predator
Prey
Polar Bear
Camel
Cactus
Wind pollinated flower
Insect pollinated flower
B2f Survival of the Fittest
Fossils give evidence
Fossils’ position in rock layers
Fossil formation
Fossil record – incompleteness
Environment change
Natural selection
Adaptations
Examples
Darwin’s’ theory
Theories of evolution
Lamarck’s theory of evolution
special survival features  better able to compete for limited resources
eyes – front of head (judge size/distance); camouflage (not seen by prey); sharp teeth/claws; built for speed
eyes – side of head (wide field of view); camouflage; live in groups (many eyes); built for speed
thick white fur (camouflage and insulation); layer of fat – blubber (insulation); sharp claws and teeth;
strong leg (running and swimming); large size/small ears (reduce surface area/reduce heat losses;
large feet (spread load on snow); fur on soles of paws (insulation/grip)
hump containing fat (doesn’t insulate whole body); tolerance to body temperature rises (doesn’t need to sweat);
bushy eyelashes/hair-lined nostrils that can close (stop sand entering); large feet (spread load on sand)
rounded shape (reduces surface area/volume ratio), thick cuticle leaves reduced to spines to reduce water loss
spines (discourage animals); green stem (photosynthesis); water storage (withstand drought); long roots (water)
feathery stigma; small light pollen
colourful petals; nectar; ‘sticky’ pollen
of past organisms; of changes; of extinctions
show evolutionary changes over long periods of time; different interpretations
hard body parts (shells, bones, leaves); covered in sediment, gradual replacement by minerals;
casts/impressions; preservation in amber, peat bogs, tar pits, ice
some body parts (soft tissue) decay so do not fossilise; fossilisation rarely occurred; fossils not yet discovered
some animal and plant species survive or evolve but many become extinct
animals and plants that are better adapted to their environment are more likely to survive; change over time
are controlled by genes and these genes are passed onto the next generation
occurrence of dark or pale forms of the peppered moth in areas with different levels of pollution;
bacteria becoming resistant to antibiotics; rats that are resistant to the rat poison warfarin
presence of natural variation; competition for limited resources; ’survival of the fittest’; inheritance of ’successful’
adaptations; extinction of species unable to compete.
met with an initially hostile response (social and historical context)
by inheritance of acquired characteristics – different from Darwin’s theory and why it was discredited
acquired characteristics do not have a genetic basis
B2g Population out of Control?
Human population
Developed countries
Finite resources
Pollution
Acid rain
Global warming
Ozone depletion
Indicator species
B2h Sustainability
Extinct animals
Endangered species
Reasons for extinction/endangered
Conservation programmes – methods
Conservation programmes – reasons
Whales commercial value
Whales in captivity
Whale biology
Whaling – problems
Sustainable development
Fish stocks/woodland
Sustainability
increasing exponentially so a related increase in use of resources and production of pollution
small proportion of the world’s population – greatest impact on the use of resources and production of pollution
non-renewable resources such as fossil fuels/minerals
household waste; sewage; SO2 (burning fossil fuels); CO2 (burning fossil fuels); CFCs
from sulphur dioxide
from increasing levels of carbon dioxide
from CFCs in upper atmosphere
whose presence/absence indicates the level of pollution;
water pollution (blood worm, waterlouse, sludgeworm, rat-tailed maggot; air pollution (lichen)
mammoth, dodo, sabre toothed tiger
whales, panda, gorilla, red kite, red squirrel, osprey – in danger of becoming extinct
climate change; habitat destruction; hunting; pollution; competition
protecting habitats; legal protection; education programmes; captive breeding; creating artificial ecosystems
protecting human food supply; ensuring minimal damage to food chains; future identification of plants for medical
purposes; cultural aspects
tourism when alive; food, oil and cosmetics when dead
entertainment, research, captive breeding programmes and lack of freedom
some aspects are still not fully understood: communication, migration patterns and survival at extreme depths
getting international agreement, policing laws and culling for research
the use of resources without depleting
sustained and yet exploited by education; quotas on fishing; re-plantation of woodland
requires planning and co-operation at local, national, and international levels