Biodiversity Flashcards
What Is A Species?
They are capable of breeding to produce living, fertile offspring.
The Binomial System?
Universal system based on Latin/Greek names,
The first name is called the generic name and denotes the genus to which the organism belongs. This is equivalent to the surname used to identify people and shared by close relatives,
The second name is the specific name and denotes the genus to which the organism belongs. This is equivalent to the first (or given) name used to identify people. However, this name is never shared with other species.
Rules Of Binomial System?
Names are printed in italics or, if handwritten, are underlined to indicate that they are scientific names,
First letter of the generic name is upper case, but the scientific name is lower case,
If the specific name is not know, it can be written as ‘sp’ E.g. Felix sp.
Courtship Behaviour?
Courtship behaviour allows species to reproduce when a female is producing eggs,
Courtship behaviour helps to achieve this by:
- Recognise members of their own species; to ensure mating only takes place between members of the same species, resulting in fertile offspring,
- Identify a mate that is capable of breeding; because both partners need to be sexually mature, fertile and receptive to mating,
- From a pair bond; that will lead to successful mating and raising of offspring,
- Synchronise mating; so that it takes place when there is the maximum probability of the sperm and egg meeting,
- Become able to breed; by bringing a member of the opposite sex into a physiological state that allows breeding to occur.
Females?
Females of many species undergo a cycle of sexual activity in which they can only conceive during a short period of time, around the time they are producing eggs,
Courtship behaviour is used by males to determine weather the female is at the perceptive stage,
If she responds with an appropriate behaviour, courtship continues and is likely to result in offspring,
If the female is not receptive, she will exhibit a different pattern of behaviour and the male will cease to court her, turning attention elsewhere.
The Principles Of Classification?
Organising species into groups,
This is called taxonomy,
Two main forms of biological classifications, each with a different purpose:
- Artificial classification,
- Phylogenetic classification.
Artificial Classification?
Type of classification,
Divides organisms according to differences that are useful at the time,
Such features may include colour, size, number of legs, leaf shape, etc,
These are described as analogous characteristics where they have the same function but do not have the same evolutionary origins,
E.g. the wings of butterflies and birds are both used for flight but they originated in different ways.
Phylogenetic Classification?
Type of classification,
Is based upon the evolutionary relationships between organisms and their ancestors,
Classifies species into groups using shared features derived from their ancestors,
Arranges the groups into a hierarchy, in which the groups are contained within larger composite groups with no overlap,
Relationships in phylogenetic classification are partly based on homologous characteristics, which have similar evolutionary origins regardless of their function,
E.g. arm of human and wing of bird both have the same basic structure and evolutionary origins and therefore homologous.
Taxonomy?
Each group with a phylogenetic classifications is called a taxon (plural taxa),
Taxanomy is the study of these groups and their postitions in the hierachial order where they are known as taxonomic ranks,
Domain - highest taxonomic rank and the three are; Bacteria, Archaea and Eukarya.
Bacteria?
A group of single-celled prokaryotes with the specific features:
- Absense of membrane-bounded organelles such as nuclei or mitochondria,
- Unicellular, although cells may occur in chains or clusters,
- Ribosomes are smaller than in Eukaryotic cells,
- Cell walls are present and made of murein (but never chitin or cellulose),
- Single loop of naked DNA made up of nucleic acids but no histones.
Archaea?
A group of single-celled prokaryotic that were originally classified as bacteria which they resemble in appearance,
They differ from bacteria because:
- Their genes and protien synthesis are more similar to eukaryotes,
- Their membranes contain fatty acid chains attached to glycerol by ether bonds,
- There is no murein in their cell walls,
- They have a more complex form of RNA polymerase.
Eukarya?
A group of organisms made up of one or more eukaryotic cells,
Their features are:
- Their cells possess membrane-bounded organelles such as mitochondria and chloroplasts,
- They have membranes containing fatty acids atached to glycerol by ester bonds,
- Not all possess cells with a cell wall, but where they do it contains no murein,
- Ribosomes are larger than bacteria and archaea.
Eukarya Domain?
Is divided into 4 kingdoms:
- Protoctista,
- Fungi,
- Plantae,
- Anamalia.
Phyla?
The largest group within each kingdom,
Organisms in each phylum have a body plan radically different from organisms in any other phylum.
Class?
The second largest group within a phyla,
Diversity within each each phylum allows the organism to be divided into classes.
Order Of Ranks In Taxonomy?
Kingdom, Phylum, Class, Order, Family, Genus, Species.
Order?
Each class is divided into orders of organisms that have additional features in common.
Family?
Each order is divided further into families and at this level the differences between organisms are less obvious.
Genus?
Each family is divided into genera and genus (singular).
Species?
Each genus is divided into species.
Phylogeny?
The hierarchical order of taxonomic ranks is based upon the supposed evolutionary line of descent of the group members,
This evolutionary relationship between organisms is known as phylogeny,
The term is derived from the word ‘phylum’, which, in classification, is a group of related or similar organisms,
The phylogeny of an organism reflects the evolutionary branch that led up to it,
The phylogenetic relationships of different species are usually represented by a tree-like diagram.
Phylogenetic Tree?
The phylogenetic relationships of different species are usually represented by a tree-like diagram, called a phylogenetic trees,
In these diagrams, the oldest species is at the base of the tress while the most recent ones are represented by the ends of the branches.
Show common ancestor.
Biodiversity?
General term to describe variety in the living world,
Refers to the number and variety of living organisms in a particular area and has three components.
Components Of Biodiversity?
Three components of biodiversity:
- Species diversity,
- Genetic diversity,
- Ecosystem diversity.
Species Richness?
A measure of species diversity,
Is the number of different species in a particular area at a given time (community),
Two communities may have the same number of species but the proportion of the species may differ.
Species Diversity?
Refers to the number of different species and the number of individuals of each species within any one community.
