3. 1. 1 - Principles of classification

Question 1

define biodiversity

Answer 1

a measure of the variety of living organisms and their genetic differences

Question 2

why is it important to classify organisms?

Answer 2

• when biologists are talking about a particular organism, they need to be sure they are all referring to the same one –> use an internationally recognised classification system
• by classifying organisms, we can quantify biodiversity. This way scientists can monitor how populations change
• a good classification system can help scientists understand ancestral relationships

Question 3

define evolution

Answer 3

process by which natural selection acts on variation to bring about adaptations and eventually speciation

Question 4

define taxonomy

Answer 4

the science of describing, classifying and naming living organisms

Question 5

what is the history of taxonomy?

Answer 5

• people grouped organisms mainly on their morphology and often used analogous features to classify organisms
• it is easy for this system to lead to misconceptions
• in order for it to be valid: homologous structures should be used

Question 6

define morphology

Answer 6

the study of the form and structure of organisms

Question 7

define analogous features

Answer 7

features that look similar or have similar function, but are not from the same biological origin

Question 8

define homologous features

Answer 8

structures that genuinely show common ancestry

Question 9

what are the main taxonomic groups?

from largest to smallest

Answer 9

Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species

Dawn’s King Prawn Curry or Fat Greasy Sausages

Question 10

what are the three domains

Answer 10

Archaea
Bacteria
Eukaryota

Question 11

What kingdoms are within the Archaea domain?

Answer 11

1. archaebacteria
   - ancient bacteria thought to be early relatives of the eukaryotes
   - particularly found in soil

Question 12

what kingdoms are within the Bacteria domain?

Answer 12

1. Eubacteria
   - true bacteria (that cause disease and that are useful in the digestive systems of many organisms and in recycling nutrients

Question 13

what kingdoms are within the Eukaryotic domain?

Answer 13

1. Protoctista
   - a very diverse group of microscopic organisms (some heterotrophs and some autotrophs)
   - some are animal like, plant like or fungi like
2. Fungi
   - all heterotrophs (most are saprophytic and some are parasitic
   - they have chitin, not cellulose, in their cell walls
3. Plantae
   - almost all autotrophs
   - include the mosses, liverworts, ferns, gymnosperms and angiosperms (flowering plants)
4. Animalia
   - all heterotrophs
   - include invertebrates (e.g insects, worms) and vertebrates (e.g fish, reptiles, birds and mammals)

Question 14

what is a heterotroph?

Answer 14

have to eat other organisms

Question 15

what are autotrophs?

Answer 15

make their own food by photosynthesis using light captured by the green pigment chlorophyll

Question 16

what is the binomial system?

Answer 16

a system of naming organisms

• every organism is given two Latin names
• first is the genus name
• second is the species/ specific name that identifies the organism precisely

Question 17

what are the rules to writing binomial names?

Answer 17

1. use italics
2. genus name has an upper case letter but the species name has a lower case letter
3. after the first use, the name can be abbreviated to the initial of the genus and the species name

Question 18

what is a genus?

Answer 18

a group of species that all share common characteristics

Question 19

what are archaebacteria?

Answer 19

ancient bacteria thought to be the oldest form of living organism
- kingdom within the archaea domain