10.1- SPECIES AND TAXONOMY Flashcards
What is classification?
organisation of living organisms into groups
What is species a basic unit of?
basic unit of classification
What is one main thing that is common of members of a single species?
they’re capable of breeding to produce living, fertile offspring
What can happen in theory when a species reproduces sexually?
any of the genes of its individuals can, in theory, be combined with any other
Why is the binomial system called so?
organisms identified by two names
What sort of system is the binominal system? (features)
universal system
What names does the binomial system use? (features)
latin or greek
What is the first name of the binomial system? (features)
generic name
What does the first name of the binomial system denote? (features)
genus to which organism belongs
What is the second name of the binomial system called? (features)
specific name
What does the second name of the binomial system denote? (features)
species to which organism belongs
What is done to the binomial names to show they’re scientific names?
printed in italics or if handwritten, they’re underlined
What case are the letters of the names from the binomial system?
first letter of generic name in upper case, but specific name in lower case
What can it be written as if the specific name is not know- binomial system?
sp
What is the classification of species regularly changing based on?
knowledge of their evolution, physical features, biochemistry and behaviour increases
Why do members of same species resemble one another physically + biochemically?
have similar or same genes
What does members of a species resembling each other physically + biochemically help to do?
help to distinguish members of own species from other species
What is the behaviour of members of same species like in comparison to members of different species?
behaviour of members of same species more alike than that of members of different species
What is the ability to display a behaviour determined by?
genetically determined
What is the means by which a species can survive over time?
reproduction
Why is it important to ensure that mating is successful + that offspring have maximum chance of survival?
female of most species only produce eggs at specific times, often as little as once a year
How does courtship behaviour help to ensure mating successful? (5)
recognise members of own species
identify mate that’s capable of breeding
form pair bond
synchronise mating
become able to breed
What does recognising members of own species ensure- courtship behaviour?
ensure mating only happens between members of same species as only members of same species can produce fertile offspring
Why does courtship behaviour help identify mate that’s capable of breeding?
as both partners need to be sexually mature, fertile + receptive to mating
What does forming a pair bond lead to- courtship behaviour?
lead to successful mating + raising of offspring
How does synchronise mating help with successful mating?- courtship behaviour
so it happens when there’s maximum probability of sperm + egg meeting
How does becoming able to breed help with successful mating?- courtship behaviour
by bringing a member of opposite sex into physiological state that allows breeding to happen
What is courtship behaviour used by males to determine?
whether female is at receptive period of cycle of sexual activity
What happens if the female responds with the appropriate behavioural response?- courtship
courtship continues + likely to result in production of offspring
What happens if the female is not receptive? -courtship
she exhibits different pattern of behaviour + male ceases to court her, turning his attentions elsewhere
During courtship, what do animals use signals for?
use signals to communicate with potential mate + with members of own sex
What is the chain of actions same for?- courtship
same for all members of species but different for members of different species
What does the chain of actions being same for same species mean?- courtship
both individuals recognise their partner is of same species + they may be prepared to mate
What does organising species into manageable groups allow scientists to do?
allows better communication between scientists + avoids confusion
What is the grouping of organisms known as?
classification
What is taxonomy?
theory + practice of biological classification
What are the two main forms of biological classification?
artificial classification
phytogenic classification
What does artificial classification divide organisms according to?
differences that are useful at the time
What are features that organisms can be divided by- artificial classification?
colour, size, number of legs, leaf shape etc.
What are analogous characteristics?
where they have same function but don’t have same evolutionary origins
What is phylogenetic classification based upon?
evolutionary relationships between organisms + their ancestors
What does phylogenetic classification classify species into?
groups using shared features derived from their ancestors
What does phylogenetic classification, arrange the groups into?
arrange groups into hierarchy, in which groups contained within larger composite groups with no overlap
What are relationships in phylogenetic classification partly based on?
homologous characteristics
What do homologous characteristics have in similarity?
have similar evolutionary origins regardless of their functions in adult of species
What is a taxon (plural taxa)?
each group within phylogenetic biological classification
What is taxonomy the study of?
study of taxa + their positions in hierarchical order, where they’re known as taxonomic ranks
What are the taxonomical ranks based upon?
evolutionary line of descent of group members
What is a domain?- taxonomy
highest taxonomic rank
What are the three recognised domain?
bacteria
archaea
eukarya
What are bacteria?
group of single-celled prokaryotes
Bacteria features: what is absent in bacteria?
absence of membrane-bound organelles i.e. nuclei/ mitochondria
Bacteria features: how many cells do they consist of?
unicellular, although they may occur in chains or clusters
Bacteria features: what are their ribosomes like in comparison to eukaryotic cells?
ribosomes smaller (70S) than in eukaryotic cells
Bacteria features: what are their cell walls made of?
murein
Bacteria features: what is their DNA like?
single loop of naked DNA made up of nucleic acids but no histones
What are archaea?
group of single-celled prokaryotes
What were archaea originally classified as?
originally classified as bacteria which they resemble in appearance
How do archaea differ from bacteria: genes + protein synthesis?
their genes + protein synthesis more similar to eukaryotes
How do archaea differ from bacteria: what do their membranes contain?
membranes contain fatty acid chains attached to glycerol by ether linkages
How do archaea differ from bacteria: what is not present in their cell walls?
no murein in their cell walls
How do archaea differ from bacteria: what is their RNA polymerase like?
have more complex form of RNA polymerase
What are eukarya?
group of organisms made up of one or more eukaryotic cells
What type of organelles do eukarya possess?
possess membrane-bound organelles i.e. mitochondria + chloroplasts
What do eukarya membranes contain?
have membranes containing fatty acid chains attached to glycerol by ester linkages
What are the cell walls of those eukarya that have cell walls, not contain?
contains no murein
What are the ribosomes of eukarya like in comparison to bacteria + archaea?
ribosomes larger (80S)
What is the eukarya domain divided into? (4)
protoctista
fungi
plantae
animalia
Within each of the eukarya kingdom, what is the largest groups known as?
phyla
What do organisms in each phylum have a body plan like?
have body plan radically different from organisms in any other phylum
What does diversity in each phylum allow?
allows it to be divided into classes
What is each class divided into?
orders of organisms that have additional features in common
What is each order divided into?
families
What are the differences at the level of families like?
differences less obvious
What is each family divided into?
genera
What is each genus divided into?
species
What is the hierarchical order of taxonomic ranks based upon?
supposed evolutionary line of descent of group members
What is phylogency?
evolutionary relationship between organisms
What does the phylogeny of an organism reflect?
reflects evolutionary branch that led up to it
What are the phylogenetic relationships of different species usually represented by?
tree-like diagram called phylogenetic tree
Where are the oldest and most recent species on phylogenetic trees?
oldest species at base of tree
most recent ones represented by ends of branches
