4.5 Species and taxonomy Flashcards
Define species
- Organisms with shared characteristics that can interbreed to produce fertile offspring
Why doesn’t the definition of a species work
- Doesn’t fit for single-celled organisms since they don’t interbreed
- There’s a lot of variation between individuals in a species (e.g. in dogs)
Even where groups of extinct organisms have left fossils records, it is very difficult to distinguish different species. Suggest 2 reasons why
- Can’t interbreed fossils to see whether they produce fertile offspring
- Not all characteristics can be observed
- Fossil records are pretty incomplete
What is the behaviour of members of the same species like
It’s more alike than that of members of different species
Suggest why it’s often difficult to classify organisms as distinct species
Variation within a species is very large
How does organisms of the same species acting in a similar way beneficial to the organisms
Individuals can recognise member of the same species by the way they act
How is the ability to display behave determined
Genetically determined
What 5 things do courtship behaviours do that enables successful mating and that the offspring have the max chance of survival
- Recognise member of their own species
- Identify a mate that is capable of breeding
- Form a pair bond
- Synchronise mating
- Become able to breed
Why does the fact that courtship behaviours help individuals recognise member of their own species , ensure that mating is successful
It ensures that mating only takes place between members of the same species because only members of the same species can produce fertile offspring
Why does courtship behaviours enabling identification of a mate that is capable of breeding beneficial
Since both partners need to be sexually mature, fertile and receptive to mating
Why does courtship behaviours forming a pair bond beneficial
Since this bond will lead to successful mating and raising of an offspring
Why does courtship behaviour enabling synchronised mating beneficial
It takes place when there is the maximum probability of the sperm and egg meeting
Why does courtship behaviours enabling individuals become able to breed beneficial
By bringing members of the opposite sex into a physiological state that allows breeding to occur
What is courtship behaviours in humans
Foreplay
Explain how courtship behaviours enables successful mating
- identify their own species
- Synchronises mating and therefore increased the chance of offspring reaching reproductive age
- Female being receptive
- Creating a pair bond which increase the chance of fertile offspring and raising offspring
What are the 2 reasons why taxonomy is needed
- Predict characteristics
- Evolutionary relationships
What is the term of biological classification
Taxonomy
What are the 3 categories the 5 kingdom classification create
- Cell type
- Organisation of cells
- Nutrition
What is the order of the hierarchical system
- Kingdom
- Phylem
- Class
- Order
- Family
- Genus
- Species
What is meant when saying the hierarchical system groups are discrete
The groups don’t overlap
In the hierarchical system are the smaller groups have more in common or the larger groups
The smaller groups
What’s the kingdom of humans
Animals
What is the phylem of humans
Chordates
What is the class of animals
Mammals
What is the order of humans
Primates
What is the family of humans
Homonids
What is the genus of humans
Homo
What is the species of humans
Sapien
In the binomial naming system what 2 categories are used
Genus followed by the species
What language is the binomial system in
Latin
What is implied when the first word of the binomial system but the 2nd word is different for 2 organisms
The genus is the same but the species is different which implies evolution relationships
When writing the binomial system names, where is the capital letter and where is the lower case, write the human one
Capital letter of genus
Lower case of species
Homo sapien
What must you do when writing binomial system names
Underline when written by hand
What do phylogenetic trees show
Shows the evolutionary relationships
In a phylogenetic tree, what is the name of when the 2 lines split
- Points of divergence
- Common ancestors
What is the name of the line from the original ancestor to the end of the branch in a phylogenetic tree
Line of descent
What are homologous structures
Features with the same fundamental structure but different function
Homologous structures show what type of evolution
Divergent evolution
Name an example of homologous structures
Pentadactyl limbs
What are analogous structures
Different fundamental structures but same function