classification and evolution Flashcards
name the 5 kingdoms (old)
prokaryote
protoctista
fungi
plantae
animalia
what are the 3 domains
bacteria
archaea
eukarya
what are the differences between archaea and bacteria
archaea doesn’t have a cell wall with peptidoglycan
enzyme RNA polymerase is different
development of flagella is different
archaea has protein bound histones (similar to eukaryotes)
what are some similarities between archaea and bacteria
no nucleus - circular DNA
lack membrane bound organelles
unicellular
what are some similarities between archaea and eukaryotes
similar enzymes eg. RNA polymerase
similar DNA replication and RNA formation mechanisms
histones
what is phylogeny
the study of the evolutionary relationships of organisms. based on the fact that all organisms share a common ancestor. More closely related organisms will share a more recent common ancestor than more distantly related organisms.
what is taxonomy
the science of identifying, describing, and classifying organisms based on their characteristics and evolutionary relationships
what is classification
involves the identifying, naming and sorting of organisms in a process called taxonomy. Organisms are classified into groups called taxa.
what is a hierarchy
A hierarchical system is one in which larger groups contain smaller groups with no overlap between groups.
define species
group of organisms that can breed together to produce fertile young
why do we need classification of species
- universal name for species - conveniant for identifying.
- predict characteristics
- understand evolutionary relationships
- keep track of. changes
what is the order of naming a species
first part of the name if the genus (captial letter at beginning)
second part of the name is the species (written in italics)
if species have the same genus what does this suggest
a close relationship
give 3 characteristics of bacteria
no membrane bound organelles
circular DNA no nucleus
unicellular
give 3 characteristics of protoctista
contain a nucleus
membrane bound organelles
most are unicellular
give 3 characteristics of fungi
chitin cell wall
contain membrane bound organelles
saprotrophic
give 3 characteristics of plantae
cellulose cell wall
autotrophic
chloroplasta
give 3 characteristics of animalia
heterotrophic
membrane bound organelles
nucleus
why do different species look similar, what kind of evolution is this
- similar environment therefore similar ecological niche
- similar selection pressures
- similar alleles will have selective advantage
- produces similar proteins so similar characteristics.
known as convergent evolution
how did early classification systems classify species?
why is this an issue?
based on observable features eg. structural or behavioural
issue as scientists dont always agree on the relative importance of different features
+ groups based on features does not tell us how related organisms are
what molecular evidence may be investigated to classify organisms
analysing similarities in proteins and DNA. more closely related, more similar molecules.
compare DNA base sequences
compare amino acid sequences
what is continuous variation
when individuals in a population vary within a range - no distinct categories
(controlled by many genes)
what is discontinuous variation
when there are 2 or more distinct categories, each individual falls into only one of these categories, no overlap.
(controlled by a single gene)
what was darwins contribution
- organisms produce more offspring than survive
- theres variation in the characteristics of members of the same species
- some characteristics can be passed from one generation to the next
- individuals that are best adapted to their environment are more likely to survive
