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48 Cards in this Set
- Front
- Back
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What is classification? |
The act of arranging organisms into groups based on their similairties and differences. |
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Why do we classify organisms? |
So scientists can identify them and to study them |
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What is taxonomy? |
The study of classification |
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How many levels are there in the taxonomic hierarchy? |
8 |
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What are the classification? |
Domain Kingdom Phylum Class Order Family Genus Species |
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Where does the hierarchy end? |
Species, contains only one type of organism |
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What are the 5 kingdoms? •Whether they're E or P •Examples of organisms •3 distinct features |
Prokaryotae; bacteria; prokaryotic, unicellular, no nucleus, small
Protoctista; algae, protozoa; eukaryotic, usually aquatic, single- celled or multicellular
Fungi; moulds, yeast; eukaryotic, chitin cell wall, saprotrophic, glycogen stores. Multi or Unicellular
Plantae; mosses, flowers;eukaryotic, multicellular, cellulose cell wall, (make own food)
Animalia; insects, fish, mammals; eukaryotic, multicellular, hetrotropic |
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What is the name given to naming organisms? |
Binomial system |
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How do you name an organism? |
First part: Genus (Capital) Second: species (not Capital)
All underlined |
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Why was the binomial system invented? |
•To avoid confusion of common names •To communicate above language |
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What is phylogeny? |
The study of evolutionary history of organisms. Tells us who's related to whom and how closely. |
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What can be used to show common ancestors? |
A phylogenetic tree |
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Why do the methods of taxonomy constantly change? |
More scientific knowledge More discoveries More technology Found differences between |
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How do you you know when a species is more closely related to one species or another? |
By seeing how closely the branches are in the phylogeny tree. The further apart the branches are, the longer ago the species diverged |
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Classifying organisms by taking phylogeny in account is know as what? |
Clasdistics |
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Why do scientist not classify organisms solely based on their observable features? |
They can't always agree on the relative importance of different features
Groups based solely on physical features may not show how related organisms are |
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How can two organism have similar observable features yet genetically, not be related at all? |
Because they live in similar environments and certain observable features which is similar on both organisms is a cause of natural selection |
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Give an example when two organisms who look similar are not related |
Sharks and whales. Fish Vs mammal |
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The more similar organisms are based on observable features and other evidence, the more... |
Closely related the are |
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What can you use to measure how closely related two organism are? |
•Molecular evidence: similaries in their proteins and DNA (base order) •Embryological evidence: similarities in early stages of development •Anatomical evidence: similarities in structure and function of body parts •Behavioural evidence: similarities in behaviours and social organisation |
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What can the development of new technologies result in? |
New discoveries such as new DNA techniques and better microscopes which would clarify the relationships between organisms |
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What are the 3 domains? |
Eukarya Archae Bacteria |
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Which organisms go under each Domain? What is the main difference between the 3 Domains? |
Eukarya: Fungi, Plantae, Protoctistica and Animalia. Nucleus present
Archae and Bacteria: Prokaryotes. Unicellular with no nucleus
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Why was the Three Domain System proposed? What type of evidence led to this discovery? |
Because molecular evidence showed large differences between Archae and Bacteria and so Prokaryotes was reclassified under those |
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What was the molecular evidence which indicated Archae and Bacteria were not in fact, related closely? |
•The enzyme RNA polymerase is different in both •Archae have similar histones to eukarya but Bacteria don't •The lipid bonds in their cell membranes are different •The development and composition of flagellae are also different |
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What is the conclusion that scientists made about the relation between Bacteria and Archae? |
•They both evolved separately •Archae are more closely related to Eukarya than Bacteria |
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What does the development of the Three Domain System tell us about the rate of scientific development? |
It is always improving |
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What is variation? |
The differences that exist between all individuals |
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What is intraspecific variation? |
Variation within species |
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What is interspecific variation? |
The variation that exists between species |
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Variation can either be - or - |
Continuous Or Discontinuous |
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What is continuous variation? |
When the individuals in a population vary within a range. No distinct categories. E.g. Mass of organism, yield of milk, no. of leaves, width or length of an organism |
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What is discontinuous variation? |
There are two or more distinct categories, each individual falls into one category only and there are no intermediates
E.g. Blood groups, colour of vegetable, seed shape, anti biotic resistance, pigment production |
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What can be variations caused by? |
Genetic factors Environmental factors Or Both |
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How can genes cause variation? Also give examples |
Variation causes by genetic factors is inherited. Some examples of which are blood group (humans), antibiotic resistance (bacteria).
Different species have different genes and different individuals have different alleles. The difference in genotype result in difference in phenotype |
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Variation caused by environmental factors. What causes it? |
•By differences in climate, food, lifestyle •Characteristics controlled by environmental factors CAN change over time •Examples: accents and pierced ears |
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Variation caused both. Give examples |
Genetic factors control characteristics an organism is born with but environmental factors influence how they develop
•Height: genes determine how tall an organism can grow but diet or nutrients availabity affects how tall someone actually grow •Flagellum: genes determine if microorganism can grow one but some will only grow them in certain environments (e.g. presence of metal ions)
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What statistical techniques can you use to look for variation between samples and how would you plot that? |
You can work out the mean; You can then present the results via a bell curve and the sample should follow normal distribution |
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What and why is standard deviation used? |
Standard deviation is a measure of the spread of values about the mean. It is used to measure variation within a sample |
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If the mean is 9 and the standard deviation is 3, what does that mean? |
Most of the values are spread between 6 and 12 |
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What does a large standard deviation mean? |
Values in the sample vary a lot, a small sd tells you the values are spread around the mean so it varies less |
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If there is little variation and the data all lies around the mean, what does the normal distribution curve look like? |
Steep Standard deviation is small |
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What does the normal distribution curve look like of the values vary a lot? |
The curve is fatter Standard deviation is large |
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What formula can you use to find out standard deviation? |
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How does phylogeny relate to classification? |
It is the bases of classification |
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If two organisms are placed in the same genus but different species, what does this mean? |
Similar enough to be same genus but different enough to be in separate species |
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Why can't you estimate the population of all species on Earth? |
•Not found all species •New species are being formed •Some species may be difficult to distinguish •Some may have become recently extinct |
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How does the clasdistics/ phylogenetic approach of classifying species differed from the biological species concept? |
For phylogenetic approch; •No need to test for interbreeding •Can apply to asexually reproduced organisms •Can apply to extinct organisms |
