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32 Cards in this Set
- Front
- Back
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What causes tobacco to be cancerous? |
Tar in tobacco contains carcinogens, which causes mutations and forms cancer |
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What makes tobacco addictive? |
The nicotine is addictive which makes giving it up difficult and causes people to smoke for longer |
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Explain how stimulants affect neurotransmissions? |
Stimulants act at the synapse, more neurotransmitters and so speeds up neurotransmission |
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What is vasodilation? |
Widening of blood vessels near the skin to allow warm blood to travel near skin surface. Body loses heat by radiation |
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Order of how we classify organisms |
Kingdom, Phylum, Class, Order, Family, Genus, Species |
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Name five kingdoms |
Animalia, plantae, fungi, protocista, prokaryote |
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Main characteristics of animalia |
Multicellular, do not have cell walls, do not have chlorophyll, heterotrophic |
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Plantae main characteristics |
Multicellular, cells walls, chlorophyll, autotrophic |
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Fungi main characteristics |
Multicellular, has cell walls, no chlorophyll, saprophytic |
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Protoctista main characteristics |
Unicellular, has a nucleus E.g algae |
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Prokaryote main characteristics |
Unicellular, has no nucleus e.g bacteria |
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Why do we class viruses in none of the kingdoms? |
Regarded as non-living. Have to live off and in other things to survive, they cannot reproduce themselves. Have to invade cells and make them reproduce the invading virus |
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When is something classified in the phylum chordata? |
Animals with a supporting rod like structure running the length of the body |
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When is something classified as a vertebrate? |
Organism with a backbone |
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How we do we classify vertebrates? |
How they absorb oxygen How they reproduce How they regulate their body temperature |
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What are the problems with assigning vertebrates to a specific group? |
Anatomy and reproduction methods can go into multiple groups e.g platypus |
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Définition of a species? |
Species are organisms that can interbreed to produce fertile offspring |
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What are the limitations of the fertile offspring definition? |
Asexual reproduction Some hybrids are fertile |
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Why is binomial classification important? |
Needed to indentify, study and conserve species and can be used to target conservation efforts Latin language, prevents confusion and allows a universal name. Species at threat can be identified |
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How can accurate classification be complicated? |
Variation within a species Hybridisation in ducks Ring species |
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What term means an organism is tolerant to high levels of salt, high temperatures or high pressure? |
Extremophiles |
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Polar bears have a small surface area Why? |
So that they radiate less heat, as less surface area is exposed to the outside temperatures |
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Polar bear adaptations? |
Thickness of insulating coat Amount of body fat Camouflage |
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How do creatures live on the deep ocean beds? |
Pressure is great. Have large mouths to collect scraps of food And/or large eyes to cope with dim/or no light |
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Darwins theory of evolution |
Variations within a species Over production Limited resource Advantageous Characteristic Survival of the Fittest Species without characteristic die out Gradual change occurs, specie evolves |
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Example of continuous variation |
Range with no distinct category E.g height and weight |
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Example of discontinuous data |
Characteristic can be placed in a distinct category E.g. Blood type, eye colour |
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How does genetic variation effect us? |
Can cause mutations that we have inherited Reproduction creates a randomness of possible gene combinations |
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How does environmental variation effect us? |
Sun tan - cause extra pigment in our skin Withering plants |
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What is a hormone? |
Hormones are chemical messengers which travel in the blood to activate target cells |
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What is a neurone? |
transmists information ad electrical impulses around the body |
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What is a synapse? |
Connection between two neurones. Is a tiny gap. The nerve impulse is transmitted by chemicals called neurotransmitters which diffuse across the gap. These set off a new electrical impulse into the next neurone |
