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
outline darwins theory of natural selection
- individuals within a population show differences in phenotypes
- selection pressures create a struggle for survive
- individuals better adapted are more likely to survive, reproduce and pass on their advantageous adaption to offspring
- over time prop. or population possessing the advantageous adaptaition increases
- over generations this leads to evolution as the favourable adaptation becomes more common in the population
what evidence is there to support evolution
fossil records - arranging in chronological order can observe gradual changes in organisms eg. increase in size
genomic DNA - sequencing of genomes can tell us how closely related organisms are
molecular - important molecules tend to be highly conserved between organisms for example Cytochrome C (protein involved in respitation)
what is the difference between phylogeny and classification
classification is simply sorting organisms into groups, phylogeny investigates evolutionary relationships between organisms
what are the 3 types of adaptations
behavioural - way an organism acts
physiological - processes inside the body eg. lowering rate of metabolism
anatomical/structural
what are the differences between marsupial mammals and placental mammals
marsupial: short gestation period
dont develop full placenta
born early into development + climb into pouch where they continue developing
placental: longer gestation period
developed placenta
born more fully developed.
what are some anatomical adaptations of the marsupial and placental mole
no external ears- more streamlined head for burrowing
scoop shaped powerful front paws for digging
specialised claws
tube shaped body - easy to push through sand and soil.
what are some consequences of pesticide resistence
crop infestations harder to control
takes time and money to create and identify new pesticide.
may have to use broader pesticides which may kill. beneficial insects.
what is divergent evolution
occurs when two species share a common ancestor and evolve one or more characteristics that make them different to each other
outline the different ways of investigating whether two organisms are the same species
- fertility - breed together, if produce fertile young, they are the same species
- morphology - compare several individuals, if several physical features are similar, same species
- ecology - observe how they function in the wild, if occupy the same niche, same species
- genetics - comapre DNA using electrophoresis, if same banding pattern, same species.
