classification and behaviour Flashcards
what is a species?
a group of organisms that can interbreed to produce fertile offspring.
suggest why two different species are unable to produce fertile offspring.
different species have different chromosome numbers so the offspring produced may have an odd chromosome number - so homologous pairs cannot form, meiosis cannot occur to produce gametes.
why is classification important?
it allows us to organise a great diversity of life into smaller manageable groups.
what is taxonomy?
the study of biological classification.
what is a hierarchy?
where smaller groups are placed within larger groups with no overlap between groups.
name the taxa in the hierarchy of classification.
domain (3) - eukaryote, prokaryote, archaea
kingdom (5) - animal, plant, fungi, prokaryote, protoctist
phylum - based on body plan (vertebrae/in-vertebrae)
class - diversity in each phyla (mammal, reptile etc)
order - further division with common features
family - usually same as genus, ends in dae
genus - species evolved from a common ancestor.
species
how is each species universally identified?
a binomial consisting of the name of its genus and species e.g
homo sapiens
describe a phylogenetic classification system.
species arranged into groups (taxa) based on evolutionary relationships (between the organisms)
what is a phylogenetic tree?
a tree like diagram that represents the phylogenetic relationships of different species.
why is behaviour important?
it helps us to classify organisms:
- individuals recognise members of their own species by the way they act.
- organisms of the same species have similar behaviour.
- some behaviour is genetically determined.
explain why courtship behaviour is necessary.
it helps to ensure successful mating (reproduction is essential for survival)
how does courtship behaviour help achieve successful mating?
- allows recognition of members of their own species.
- allows identification of sexually mature male (opposite sex)
- forms a pair bond (helps to raise offspring)
- synchronise mating (increase probability of sperm and egg meeting)
