Term
Identification of organisms by dichotomous key
Branching keys are easy to use, but take up a lot of space. |
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Definition
¹ Does the organism have cells with a definite nucleus?
NO - It is a bacterium
YES - Go to question 2
² Is the organism made up of many different cells?
NO - It is a protoctistan
YES - Go to question 3
³ Is the organism a heterotroph?
NO - It is a plant
YES - Go to question 4
Does the organism have cell walls and does it feed by external digestion?
NO - It is an animal
YES - It is a fungus |
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Term
| Binomial System of Nomenclature |
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Definition
| The convention of giving organisms a two-part name made up of their genus and species. |
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Term
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Definition
Heterotrophic organisms have to acquire and take in all the organic substances they need to survive. So heterotrophic nutrition is obtained by digesting organic compounds.
Animals, fungi, many prokaryotes and protoctists are unable to synthesize organic compounds to use as food. They are called heterotrophs.
All heterotrophs depend on autotrophs for their nutrition. |
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Term
| Four types of heterotrophic nutrition |
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Definition
1.Holozoic nutrition: Complex food is taken into a specialist digestive system and broken down into small pieces to be absorbed. This consists of 5 stages, ingestion, digestion, absorption, assimilation and egestion.
2.Saprobiontic/saprotrophic: Organisms feed on dead organic remains of other organisms.
3.Parasitism: Organisms obtain food from other living organisms (the host), with the host receiving no benefit from the parasite.
4.Mutualism: A symbiotic relationship between organisms, with each contributing and benefiting from each other. |
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Term
| Hierarchy of classification |
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Definition
The sequence of kingdom:
- phylum,
- class,
- order,
- family,
- genus and
- species
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Term
| Vertebrates and invertebrates |
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Definition
| All animals feed on organic molecules.$$$Animals with a backbone are called vertebrates.$$$Those without a backbone are called invertebrates. For example:$$$Nematodes, Annelids, Molluses and Arthropods. |
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Term
| Nematodes$$$Hookworms are nematodes often living as parasites inside the gut of another animal. Their bodies are specialised for feeding and reproducing; |
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Definition
| Mouth: with sucking mouth parts for drinking blood.$$$Long, thin body so not washed out of host's intestine.$$$Has long muscles for wriggling movements.$$$Body covered with mucus to resist attack by host's digestive juices.$$$Large sex organs to produce many sperm and eggs.$$$Anus. |
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Term
| Annelids$$$Annelids such as the earthworm have a long segmented body and chaetae |
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Definition
| Long, cylindrical body covered with a mucus layer helps to stop drying out$$$Single segment$$$Mouth can bite off pieces of fallen leaves$$$Chaetae(bristles) are found on each segment - used during movement$$$Clitellum: used to bind two worms together during sexual reproduction |
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Term
| Molluscs$$$Molluscs have a hard shell protecting a soft bodywith no limbs.$$$Snails have a single, coiled shell |
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Definition
| Shell: hardened by calcium carbonate. Protects the soft body of the snail from predators and from drying out. The whole body can be withdrawn into the shell.$$$Mouth parts to scrape at vegetation$$$Eye on tentacle$$$Foot: muscle with a slimy covering so that snail can move by creeping over the surface. |
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Term
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Definition
| Apart from insects, the arthropod phylum includes three other classes:$$$Crustacea, Myriapods and Arachnids. |
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Term
| Insects$$$e.g. housefly, mosquito |
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Definition
| The body is segmented, with thes egments grouped into head thorax and abdomen.$$$Compound eyes: detect food and avoid predators.$$$Two pairs of wings for flying (rear set may be absent or not used for flying).$$$Antennae: sense chemicals in the environment.$$$Mouthparts: very specialised for feeding e.g. piercing by mosquitoes$$$Three pairs of legs, attached to the thorax. Allow walking movements, over food or to avoid predators.$$$The adult blowfly is highly adapted for locomotion (aids dispersal) and reproduction. |
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Term
| Metamorphosis$$$'change of body form' |
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Definition
| allows different stages which:$$$do not compete for the same food sources $$$can be highly specialised for different functions. $$$The larva is adapted for feeding and growth, and the adult for locomotion and reproduction |
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Term
| Crustacea$$$(Crabs are slightly unusual because many of their segments are tucked under their body) |
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Definition
| Hardened, serrated edge to claw: can hold onto slippery food, and break open shells of molluscs.$$$Jointed limbs: flexible to help with feeding$$$Carapace: a thick,hardened shell for protection against predators$$$Gills under shell: allow uptake of oxygen from water$$$Eyes: important sensorsin aquatic environment. |
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Term
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Definition
| Antennae: these are important sense organs in the millipedes' dark, damp environment. They can 'sense' chemicals and the level of moisture in the environment.$$$Mouthparts: these aremodified legs! Have hard edges for biting vegetation (millipedes) or other animals (centipedes).$$$Hard exoskeleton: protection against predators.$$$Walking legs: have many joints and internal muscles, and allow movement ove rrough surfaces$$$Body covering: waterproof,helping animal to live on land$$$Many body segments: body is flexible for movement and wriggling around and under leaves and stones. |
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Term
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Definition
| Head and thorax are combined into one body part, the$$$cephalothorax.$$$Powerful, piercing jaws (all spiders are predators)$$$Simple eyes (but more than one pair) help to detect prey.$$$Four pairs of legs attached towards the rear of the cephalothorax. Allow chasing prey or holding onto web$$$Abdomen$$$Spinneret which produces long, thin strands of silk. |
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Term
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Definition
| Similar requirements to those of bacteria:$$$Moist environment (to absorb the soluble products of digestion of their food source)$$$Warm environment (enzymes work at optimum temp.)$$$Nutrient source (to provide the raw materials and energy required for growth).$$$Fungi do not require light since they do not rely on photosynthesis (light environments are too warm and dry for fungal growth). |
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Term
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Definition
| Iodine solution from brown to blue black |
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Term
| Test for Reducing sugars (Glucose) |
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Definition
| Benedict's solution from blue to brick red with heat |
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Term
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Definition
| Biuret's test, from blue to purple |
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Term
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Definition
| Ethanol, white emulsifier |
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Term
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Definition
| Weedkillers - The selective weedkiller contains growth hormone that causes the weeds to grow too quickly. $$$$$$Rooting powder - makes stem cuttings quickly develop roots. $$$$$$Controlling fruit ripening - Some hormones slow the ripening of fruits and others speed it up. (useful for delaying ripening during transport or when fruit is displayed in shops).$$$$$$Dormancy - Dormancy stops seeds germinating until conditions are ideal for growth. Hormones can be used to remove the dormancy of a seed so it can germinate at all times of year. |
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Term
| Virus and bacteria compared |
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Definition
| ...........................|........ Virus ........|........ Bacteria ...........$$$----------------------|---------------------|--------------------------$$$Covered by ....... |... Protein coat ....|...... Cell wall ...........$$$Cell membrane ...|.......... No ...........|........... Yes .............$$$Cytoplasm ..........|........... No ...........|........... Yes ............$$$Genetic material .|... DNA or RNA - ..|... DNA - enough for$$$ ...........................|.. only few genes |... several hundred .$$$ ...........................|........................... |... genes ................$$$Living or ............. |..... Non-living .....|.......... Living ..........$$$non-living? ..........|.. unless in host ..|............................... |
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