Module 4 Flashcards
what are the levels of classification?
Domain Kingdom phylum class order family genus species
why do we classify organisms?
to identify species
to predict characteristics
to find evolutionary link
What is a species?
A group of organisms that can produce fertile offspring
why can’t animals like mules produce fertile offspring?
because they have an odd number of chromosomes, so they can’t pair up properly during sexual reproduction
what is the name of the system we use to name organisms with their genus, species
Binomial nomenclature
what are the characteristics of Prokaryotes
unicellular
no nucleus/ membrane bound organelles
ring of DNA
nutrients absorbed/ through photosynthesis
what are the characteristics of protists?
mainly unicellular nucleus and membrane bound organelles some have chloroplasts can sometimes move by flagella can be parasitic, heterotrophic or autotrophic
what are the characteristics of fungi?
uni or multicellular chitin cell wall nucleus and membrane bound organelles no chloroplasts can't move store foo as glycogen nutrients absorbed from decaying material
what are the characteristics of plants?
multicellular chloroplasts and cellulose cell wall nucleus and membrane bound organelles do not move autotrophic store food as starch
What are the characteristics of animals
multicellular no cell wall membrane bound organelles can move with flagella/ contractile proteins heterotrophic food stored as glycogen
what size ribosomes do each of the 3 domains have?
Eukarya- 80s
Archaea- 70s
Bacteria- 70s
What is the difference between Archaea and Bacteria>
Archaea have RNA polymerase with 10 proteins, whereas Bacteria have 5. Archaea also can live in extreme conditions.
what is phylogeny?
Evolutionary relationships between organisms
What is a phylogenetic tree?
A diagram used to represent evolutionary relationships between organisms. They show that different species have evolved from a common ancestor.
How do we find most evidence for phylogenetic trees?
fossils
what is an advantage of phylogeny?
provides a continuous tree, instead of discrete groups
What are the three main pieces of evidence for evolution?
paleontology
comparative anatomy
comparative biochemistry
how do fossils provide evidence for evolution?
The least complex fossils are found in the oldest rocks, showing life became more complex as time passed
We can see similarities in anatomy of fossils to show that closely related animals have evolved from a common ancestor.
How does comparative anatomy provide evidence for evolution?
homologous structures show that many organisms came from the same ancestor and therefore share similar structures, but have evolved to perform different functions
How can we use comparative biochemistry to provide evidence for evolution?
Neutral changes in a molecules structure (has no effect as not in functional group, and therefore isn’t affected by selection pressures) happen regularly. finding the difference between molecules from two species and plotting against the known rate of neutral mutations shows how long ago they last shared a common ancestor
What are the two types of variation?
Interspecific- between species
Intraspecific, between organisms in a species
what are the two causes of variation?
genetic and environmental
what are the genetic causes of variation?
different alleles for the same gene mutations meiosis sexual reproduction chance
when are the students t test and spearman’s rank used?
t test- comparing means of two populations
spearman’s rank- to consider a relationship between two sets of data