B2- GCSE BIOLOGY MODULE 2

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Biology Topic 2	Classification Organising living organisms into groups -Natural -Artificial Can sometimes be difficult because many organisms may fit into more than one groups.
Natural Classification Based on evolutionary relationships and genetic similarities	Artificial Classification Based on appearance rather than genes. Used to identify the organism
Classification changes over time... New species may not fit into any categories, so hard to know where to place it. New research may indicate some species aren't as closely related as we thought.	Living things are divided into Kingdoms. And then the Kingdom is divided into smaller groups.
Kingdom Phylum Class Order Family Genus Species	A genus is a group of closely related species. A species can interbreed and produce fertile offspring.
Evolution is a continuous process Organisms are changing all the time, so they way they have been classified may have to change. Sometimes they eve form a new species.	Binomial System Gives everything a two part name (Latin) First part = Genus Second part= Species Avoids confusion in other languages.
Asexual Reproduction Reproduces by making a copy of itself. It does not interbreed with any other organism, so don't fit the definition of a 'species.'	Hybrids When you mix species, e.g a donkey and a horse = a mule Usually infertile, again, they aren't species.
Common Ancestors Similar species tend to have common ancestors. They may look alike and have similar habitats. However, some species have adapted to their environment, e.g Llamas and Camels	Efficiency= energy available to the next level energy that was available to previous level x100
Interspecific Competition Organisms compete for resources against another species. (Bigger Impact)	Intraspecific Competition Organisms compete for resources against the same species.
Parasites Live of a host. Take what they need to survive, and don't give anything back. Often harms the host. (Mosquitos) Win-Lose Relationship	Mutualism Both organisms benefit. Win-Win Relationship. (Bees)
Adaptations The features that organisms have to make them better suited to their environment. more able to compete, meaning more likely to survive and reproduce.	Specialists Highly adapted to survive in a specific habitat.
Generalists Organisms that have adapted to suit a range of different habitats.	Some organisms can tolerate extreme conditions, like extreme temperatures. They are called extremophiles.
Organisms that can live in the cold have adapted in many ways to reduce heat loss. They keep warm by...	Thick coat or layer of blubber trap air and insulate themselves
Large size and compact body shape to give a smaller surface area to volume ratio. This means that less body heat will be lost through the skin.	Counter Current Heat exchange system (often in Penguins) Blood vessels going to and from the feet carry blood that flows in the opposite direction. When the vessels pass, they transfer heat. This stops the cold blood cooling the rest of the body.
Behavioural Adaptations To escape the cold, organisms... Migrate to warmer climates Hibernate Huddle together	Hot Environments Keeping cool in hot environments means increasing heat loss and reducing heat gain.
Behavioural Adaptation to Hot - Spend time in the shade or underground - Be active at night, when it's cooler - Bathing in water. As the water evaporates it transfers the heat from the skin to surroundings.	Anatomical Adaptations Large surface area, which allows them to lose more body heat Large thin ears, so more heat can be radiated to the surroundings. Store fat in one particular place, e.g the camels hump.
Dry Environments (Plants) Have a rounder shape, smaller surface area. Thick waxy cuticle and spines instead of leaves to reduce water loss. Extensive roots, for a large surface area, and they also store water in their stems.	Dry Environments (Animals) Specialised kidneys thats allow them to produce concentrated urine, with little water content. No sweat glands. Spend lots of time underground where air has more moisture than on the surface.
Charles Darwin -He knew that organisms showed wide variation, and had to compete for resources. - Concluded that those that were best adapted would be more successful. "Survival of the Fittest" Theory.	Not everyone agreed with him... - The theory of evolution contradicted religious beliefs. - Darwin couldn't explain why useful characteristics appeared, or how they were inherited. - Wasn't enough evidence to convince many scientists.
Lamarck had a conflicting view... he said that if a acharctaeristsic was used a lot, the organism would develop it, this developed characteristic would be passed onto off spring. e.g. a rabbit with big leg muscles has babies with big leg muscles.	it was rejected though because characteristics don't have a genetic basis, so therefore unable to be passed onto the next generation.
People now accept Darwin's theory because... Theory has been debated and tested by a range of scientists. No one's managed to prove this wrong.
Decomposition recycling of carbon and other nutrients takes longer in water logged conditions. this is because of the fungi and bacteria that decompose the nutrients need oxygen. Water logged soils don't have much oxygen, so the decomposers have less energy- therefore taking longer.	Carbon Recycled in the Sea 1) Millions of marine organisms make shells from carbonates. 2) When these shells brake, they lie on the ocean floor and form limestone. 3) Oceans absorb CO2.
Human Impact on the Environment	- Human population is rising exponentially. - Population increase when the birth rate is higher than the death rate. - Increasing population means resources are being used up. - Large amounts of pollution
Increase in population causes 1. Global Warming 2. Acid Rain 3. Ozone Depletion	Global Warming Increased use of fossil fuels, which when burnt, release large amounts of CO2. this means that heat is being trapped in the atmosphere. Could result in the rise of sea levels.
Acid Rain When fossil fuels and waste materials are used up, they release gas called sulfur dioxide, which reacts with water, making sulphuric acid. this damages soil and trees, buildings and aquatic life.	Ozone Depletion CFC's cause a hole in the ozone layer which protects us from the harmful UV rays from the sun. being exposed to them may lead to skin cancer and plankton, a big role in the aquatic ecosystem.
Indicator Species	LICHENS Air quality. the cleaner the air, the greater number of Lichens.
MAYFLY LARVAE water quality. Cant survive in dirty water. cleaner the water, greater number of mayfly larvae there will be.	WATER LICE, RAT TAILED MAGGOTS & SLUDGEWORMS all indicate polluted water.
Advantage of using a living indicator Quick Cheap No need for expensive equipment or trained workers	Disadvantage of using a living indicator Factors other than pollution (e.g. temperature) can effect the survival of indicator species, so may not be reliable.
Advantage of using non-living methods - Reliable, numerical results - Easy to compare between sites - Exact pollutants can be identified.	Disadvantage of using non-living methods Requires more expensive equipment an trained workers
Endangered Species Species that are in danger of becoming extinct.	Species are at risk of becoming endangered if the factors below fall to a critical level: Number of habitats Number of individuals Genetic Variation
Conservation Programmes	1. Protect Human Food supply Over-fishing has greatly reduced fish stocks in the ocean. conservation programmes ensure that future generations will have fish to eat.
2. Ensuring Minimal Damage to Food Chains If one species becomes extinct, it means it will affect the whole food chain. Conservation programmes ensure that they conserve one species in the hope that they may help others survive.	3. Providing Future Medicines by cutting down rainforests, we could be losing precious medicine found in undiscovered plants, that could save many lives.
4. Cultural Aspects Individual species my be important to a nation or an area's cultural heritage, e.g America's Bald Eagle is conserved as a national symbol.
Development has to be sustainable	SUSTAINABLE DEVELOPMENT MEANS PROVIDING FOR THE NEEDS OF TODAY'S INCREASING POPULATION WITHOUT HARMING THE ENVIRONMENT.
WHALES: COMMERCIAL VALUE DEAD OR ALIVE...	DEAD: Meat, source of food. ALIVE: Tourists, Entertainment.

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B2- GCSE BIOLOGY MODULE 2

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