unit 2

• fins of a fish and fins of a whale (mammal) is an example of what

  convergent evolution
• what is the reason for using an "outgroup" in a phylogenetic tree?

  to decide which form of a trait is ancestral versus derived
• to study evolutionary relationships between widely divergent organisms, such as prokaryotes vs eukaryotes, which homologous gene sequences would be best to use?

  genes for specific ribosomal rna
• penicillin is an important antibiotic that kills bacteria with very few side effects on human cells because it 


  inhibits formation of peptidoglycan
• why is the chemical process of nitrogen fixation so important for organisms

  it is the essential first step to get atmospheric n2 into a compound like 216 (264) NH3
• which of these describes a quorum sensing response in bacteria

  cells only respond when receptors detect many inducer signals
• in the history of eukarya, which came first: chloroplast or mitochrondia

  mitochondria
• dna sequence analysis suggests that there has been a large degree of such lateral gene transfer during prokaryote evolution and early eukaryotic evolution

  genes from bacteria that were the ancestors of mitochrondia become part of the mitochrondia genome in eukaryotes
• a stable favorable environment would be a fitness advantage for

  asexual reproduction
• a changing, harsher environment is an advantage for

  sexual reproduction
• is self fertilization the same as asexual reproduction

  no, because self fertilization involves meiosis and fertilization
• which of these would be the equivalent of plants "alternation of generations in animals"

  haploid sperm products of meiosis undergo mitosis to form multicellular haploid sperm
• an organism consists of differentiated cells in specialized tissue types is an evolved, distinctive characteristic of all members of complex multicellular groups like animal kingdom
• phylogeny- the hypothesized evolutionary relationships of a group of species, represented as a phylogenetic tree
• phylogenetic tree: branching diagram that represents a hypothesis about evolutionary relationship
• taxon: each species or unit being mapped on the phylogeny
• sister groups/sister taxa: share their most recent common ancestor
• a clade is also called a monophyletic group
• a clade is a grouping that includes a common ancestor and all the descendents
• homologous structures come from the same ancestral trait
• analogous structures have a similar function but not necessarily evolved from same ancestral trait
• derived trait is one that differs from its form in the ancestor of a lineage
• ancestral trait is the form in the ancestor
• convergent evolution: independently evolved features subjected to similar selective pressures
• an example of convergent evolution: fins of a fish and fins of a whale (mammal)
• the reason to using an outgroup in a phylogenetic tree is to decided which form of trait is ancestral versus derived
• traits in the outgroup are considered to be the ancestral form of the trait, not the derived form
• a derived trait is one that differs from its form in the ancestor of a lineage
• three domains of life, archaea, bacteria, eukarya
• archaea


  prokaryotic
• bacteria


  prokaryotic
• eukarya


  eukaryotic
• true or false, nuclear envelope, organelles is only present in eukarya

  true
• bacterias cell wall material is peptidoglycan
• archaeas cell wall material varies, but there is no peptidoglycan
• animals dont have cell wall
• chitin is fungis cell wall material
• cellulose is plants cell wall material
• bacteria and eukarya both have unbranched hydrocarbons for their membrane lipids
• archaeas have diverse and some branched membrane lipids