Module 4- classification and evolution Flashcards
What is taxonomy?
identifying, naming and sorting organisms into groups
What are taxa?
groups where closely related organisms are put into
What is the phylogeny of organisms?
evolutionary relationships that helps determine which taxa an organism is part of
Name the taxas
domain, kingdom, phylum, class, order, family, genus, species
Define species
group of organisms that is able to reproduce to produce fertile offspring
Name an describe each kingdom
animalia- largest kingdom with over 1 mil species, multicellular, has nucleus and other membrane bound organelles, no cell walls or chloroplast,moves with the aid of cilia/flagella/contractile proteins, nutrients are acquired by ingestion, food is stored as glycogen
plantae-2nd largest kingdom, multicellular, has a nucleus and other memrane bound organelles, cell wall composed of cellulose, all contain chlorophyll, most don’t move, nutrients are acquired by photosynthesis, store food as starch, 250000 species
protoctista- mainly unicellular, a nucleus and other membrane bound organelles, some have chloroplasts, some are sessile but others move by cilia/flagella/amoeboid mechanisms, nutrients are acquired by photosynthesis (autotrophic feeders) and ingestion of other organisms (heterotrophic organisms)
fungi- can be unicellular or multicellular, has a nucleus and other membrane bound organelles, cell wall mainly composed of chitin, no chloroplasts or chlorophyll, no mechanism for locomotion, nutrients are acquired by absorption mainly from decaying material (saprophytic feeders), most store their food as glycogen
prokaryotae- unicellular, no nucleus or other membrane bound organelles, no visible feeding mechanism, nutrients are absorbed through the cell wall or produced internally by photosynthesis
Name the 3 different domains
archaea, bacteria, eukarya
Who was the first to propose the classification system?
Carl Linnaeus
Why do scientists classify organisms?
to easily identify species, to predict characteristics and to find evolutionary links through common ancestors
Why are mules infertile?
as their cells contain an odd number of chromosomes which means meiosis and gamete production can’t take place correctly as all chromosomes must pair up
What is the classification of humans?
D= eukarya
p= chordata
c=mammalia
o=primates
f=hominidae
g=homo
s=sapiens
How do you write the binomial name?
consists of genus and species of an organism
-must be put in itallics if typed and underlined if written
What have been the recent changes to classification systems?
-originally classification systems were based on observable characteristics/features
-through the study of genetics and other bio molecules scientists are now able to study evolutionary relationships between organisms
-when organisms evolve their DNA changes
-DNA determines the proteins that are made which in turn determines the organisms characteristics
What is the current classification system used by scientists?
3 domain system
who and when was the 3 domain system proposed by?
Carl Woese in 1977
How does the 3 domain system group organisms?
using differences in the sequences of nucleotides in the cells ribosomal RNA (rRNA) as well as the cells membrane lipid structure and their sensitivity to antibiotics
Describe each of the 3 domains
eukarya- have 80S ribosomes, organisms possessing complex sub-cellular structures
archaea- have 70S ribosomes, primitive bacteria
bacteria- have 70S ribosomes, true bacteria
What is a phylogenetic tree used for and what do they show?
-represent evolutionary relationships between organisms
-the point organisms join together is the common ancestor
-shows how different species have evolved from a common ancestor