Variety of life and Classification Flashcards
How can you test the reliability of results?
By repeating an experiment - if repeats give the same or similar results it suggests they are reliable
Independent variable
The thing YOU change in the experiment (e.g. coke or diet coke)
Dependent variable
The thing that changes that you measure (blood sugar)
Control variable
The thing that you keep the same to make it a fair test
Mean
Add all the numbers together and divide by how many numbers there are
How do you increase the reliability of the mean
By repeating the experiment and calculating a new mean
What is more precise? mm or cm?
mm
What is more precise g or mg?
mg
What goes in the first column of a table?
Independent variable (the thing YOU change)
What goes in the second column of a table?
Dependent variable (the thing that changes in the experiment)
Where do the units go in a table?
In the headings
When do you use a bar graph?
When the independent variable is categoric e.g coke / diet coke
When do you use a line graph?
When the independent variable is continuous e.g. temperature or age
What does categoric mean
Different categories of data e.g. male/female
What is a discrete number?
Things you count and do in whole numbers e.g. number of individuals
What is a continuous variable?
Things you measure like mass, length, time (and don’t have to be whole numbers)
what do plant cells contain?
multi cellular organisms, e.g. cellulose cell wall, makes own food by photosynthesis (using chlorophyll in chloroplasts to harness light energy)
What do moulds play a role in?
Moulds play a role in decay; yeast used in beer / wine / bread making.
What is single cell fungi called?
Yeast
How is Fungi organised?
It is organised into a mycelium made of thread like structures called hyphie; cell walls made of chitin; saprophytic - obtain nutrition by extracellular digestion (secrete digestive enzymes onto food and absorb soluble products).
Why does bread rise?
Bread rises due to carbon dioxide gas given off by yeast as it respires sugars.
What is single multicellular fungi called?
Mould
What is a categoric variable?
A special type of discrete variable and are described by labels like dog, cat, mouse
What is an anomalous result?
A result that is very different to other repeats and is not included when calculating the mean.
How have organisms adapted to live in different habitats?
They adapt over time, e.g. polar bears have
- big feet to spread their weight
- white fur coat to camouflage with snow
- black skin under fur to absorb sun’s heat
- thick layer of fat for insulation
- small ears to reduce surface area
How can organisms be sorted into groups?
Sorted into groups based on shared features (classification)
What are the 6 main groups of classification?
- Plants
- Animals
- Fungi
- Protoctists
- Bacteria
- Viruses (not strictly living things)
Where do Protoctists mainly live?
Pond water
What are Protoctists?
Microscopic single-celled organisms
What features do Protoctists have?
Amoeba, while others have chloroplasts and are more like plants e.g. chlorella.
What is an example of Pathogen?
It’s the malaria parasite plasmodium
What is bacteria?
Microscopic, single-celled organism; they have a cell wall made of murein
What do bacteria lack in their cells?
Nucleus, but they do contain a circular chromosome of DNA
What do bacteria play a role in?
Decay and recycling of nutrients but some cause disease like food poisoning and tuberculosis. Some are used in food production (yogurt & cheese)
Describe viruses
They are smaller than bacteria and they are parasitic and can only reproduce inside living cells, they infect every type of living orgnaism
What is the structure of a virus?
No cellular structure, just genetic material, wrapped in a protein coat, e.g. influenza virus and HIV
What are animal cells?
They are multi-cellular organisms, have no cell wall, obtain nutrients by eating, most can move from place to place and have a nervous system
How can animals be classified?
Those with and those without a backbone, e.g. vertebrates and invertebrates
What do Arthropods have?
Jointed legs and a hard exoskeleton (invertebrates)
What do insects have?
A body divided into 3 sections, 6 jointed legs, may have a pair of wings e.g. flies and beetles,
Name the different types of arthropods
Insects - flies & beetles Crustaceans - crabs Myriapods - centipedes Arachnids - spiders Molluscs - snails Anelids - earthworms
What does an Annelid have?
Long bodies divided into rings e.g. Earthworm
Name the different Vertebrates?
Mammals (hair) Birds (feathers) Fish (loose wet scales) Reptiles (dry scales) Amphibia (smooth moist skin)
What do mammals and birds have in common?
Constant warm body temperature
How do the young of mammals develop differently to other species?
The young mammals develop inside the mother whilst the other groups lay eggs
What is extra cellular digestion?
Secreting digestive enzymes on to material then absorbing soluble products of digestion
