B1

Adaptations Animal adaptations: Polar bear:White coat- camouflage for hunting/predation.Black skin- absorbs sun's energy/heat energy- channeled by transparent hollow hair tubes from surface to skin surface.Large body size- surface area to volume = small.Thick blubber- insulates against eat loss.Small ears- less surface area, reduces heat loss.Thick coat- traps air and insulates (air is a good insulator)Paws- large to distribute weight/furry to prevent slipping/slightly webbed to swim.Penguins + huddling:Penguins have a thick layer of blubber to insulate.Penguin feathers are short and fine + trap air (good insulator) next to skin.Temperatures v. cold- fluff up their feathers to trap extra air (good insulator)Penguins huddle to give shelter, move outside to in and vice versa to keep warm. Reduces surface area and reduces colonies overall heat loss.Surface Area to Volume Ratio:Bigger surface area = smaller surface area to volume ratioIncreasing body size = decrease heat loss. Plant adaptations: Water loss:Plants lose water through transpiration . Water is lost after a series of steps; Water absorbed by root hairsWater goes through rootsSuction pressure takes water up stemWater goes through leaf Lost by stomataCacti Adaptations:Surface area to volume ratio is low.Tap root goes deep underground for water.Roots close to the surface to catch rain.Thick, fleshy stem to store water.Spiky leaves/spines for protection and trap water to stop evaporation.Aloe Vera Adaptations:Succulent oils inside to avoid drying out.Spines to top herbivores from grazing.Store water in their fleshy leaves (succulents).Thick cuticle prevents water loss.Fleshy leaves that can shrivel then swell rapidly if it rains- then store water.Reduced surface area to keep from losing water.Creosote bush:Waxy leaves to reduce water loss.Folds leaves to reduce surface area- store water.Periods of extreme dry weather- sheds all its leaves.Extremophiles:Organisms that survive and thrive in extra-ordinary places with extreme conditions, i.e:Arctic/ Antarctic circleHot sulphur springsDeep in the ocean at great pressures.Near geothermal vents that are extremly hot. Competition in Animals: Competition:Term used to describe how animals (or plants) have to survive using limited resources.Some are better adapted, and so survive better and are better competitors. "Survival of the fittest" Not a good competitor- go somewhere else or die.Animals compete for:FoodSpace/territory Shelter/nest sitesWaterA mateTerritory/mate fighting:Some species (i.e lion/deer) fight to establish strength.Victor holds best territory and/or mates (all females)Attracting a mate:Fierce competitionPeacock evolved a display- tail feathers to attract females/warn malesCompeting for food (herbivores):Better competitors if eat a range of different plants, i.e Giant Panda- only eats bamboo = highly endangered.Competing for food (carnivores):Often compete for same prey, i.e. mouse hunted by owls, foxes, hawks and cats.Better competitors are well adapted for stealth, speed and well developed senses. Competition in plants: Plants compete for:LightWaterSpaceMinerals(Carbon dioxide- rainforests) Changing environments: Changes in the environment can affect the distribution of living organisms.Agriculture involves the use of fertilisers which can run off fields into rivers and pollute them.Increasing populations cause increasing housing/industry, and thus more pollution in surrounding habitats.Factors:Environmental changes are caused by different factors:Infectious diseasesPredator numbersAvailability of prey/food sourcesNumber/types of competitorsTemperature changeRainfall changeChange in level of air/water pollutionAffects populations:Population size increases e.g. prey increase, more predators survive + reproduce, so their numbers also increase.Population size decreases e.g. pesticides kill off populations, less food available, more disease.Population distribution changes e.g. hotter further north, bird migrate further north than before.Indicator species:Organisms that are very sensitive to changes in the environment.Lichens:Millions of microscopic algae, held in a mesh of fungus. Have the ability to photosynthesise.Absorb minerals/water/elements from the atmosphere directly.Can absorb over their entire surface area= very sensitive to atmospheric change.Very few lichens near industrial areas.Different lichen species have varying tolerance levels, so can be good indicators of atmospheric pollution.Aquatic indicator species:Organisms that live in water and can monitored to show water pollution levels.Mayfly nymphs show very clean water, as they cannot live in water that is polluted.Certain species are very susceptible to pollution levels.Non-living indicators:Satellites can measure temperature of sea surface and amount of snow/ice cover.Automatic weather stations measure the atmospheric temperature at various locations.Rain gauges measure rainfall to find out how much the average rainfall changes year on year.Dissolved oxygen meters, which measure dissolved oxygen in water, so can tell how the level of water pollution is changing.