3.4.5 species and taxonomy

Question 1

what is a species?

Answer 1

a group of organisms that are similar to each other but different to members from other species

similar genes, similar physical and biochemical characteristics

similar developmental patterns and immunological features

occupy the same niche

members of the same species can breed with each other to produce living fertile offspring

any of the genes of a species individuals can be combined with each other, as they belong to the same gene pool

Question 2

what are the problems with defining species?

Answer 2

1. species are not fixed
2. many species are extinct
3. some species are sterile

Question 3

courtship behaviour

Answer 3

ensure mating takes place between species

both individuals must be sexually mature

form a pair bond that will successfully raise offspring

sychronise mating so takes place to allow max probability of sperm and egg meeting

Question 4

species categories

Answer 4

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 5

previous process of naming species

Answer 5

previously done through classification of certain features of an organism

led to same names being used for different species in different parts of the world

Question 6

binomial system

Answer 6

uses latin or greek names

first name is the generic name and this is the genus of the organism

second name is the specific name and the species

Question 7

binomial system rules

Answer 7

specific name is never shared with another species within the genus

names are printed in italics or underlined if hand written

first name is capitalised and specific

Question 8

what is classification?

Answer 8

organising living organisms into groups

grouping of species = classification

practice of biological classification = taxonomy

Question 9

describe artificial classification

Answer 9

divides organisms by physical characteristics eg size

describes by the same function, not the same evolutionary origin

Question 10

natural classification

Answer 10

based upon evolutionary relationships

classifies species using shared features derived from their ancestors

arranges the groups into a hierachy - groups contained within larger groups with no over lap

Question 11

taxonomy

Answer 11

taxon = a group within each biological classification

largest taxon = kingdom, with the largest group in a kingdom being a phylum

kingdom
phylum/phyla
classes
orders
families
genera
species

Question 12

phylogeny

Answer 12

evolutionary relationship between organisms

reflects the evolutionary branch that resulted in the organisms

usually shown as a tree called phylogenetic tree