lesson 9 - bacteria and archaea Flashcards
what are the three domains of life?
bacteria, archaea, and eukarya
which domains of life are prokaryotic?
bacteria and archaea
do prokaryotes have a nucleus? (membrane bound organelles)
no
what membranes do prokaryotes have?
plasma membrane - respiratory membrane and thylakoid membrane
can oxygen build up if it reacts with iron?
no
what are stromatolites?
rocks formed by sedimentary layers on bacterial mats
what is the main source of atmospheric oxygen?
oxygenic photosynthesis by cyanobacteria
which bacteria created oxygen thru photosynthesis?
cyanobacteria
what are extremophiles?
organisms that live in extreme conditions
what are extreme halophiles?
biological organisms that thrive in highly saline environments
what are extreme thermophiles?
organisms that thrive in very hot environments
what are the three basic prokaryotic shapes?
coccus (round), bacillus (rod), spiral (twisty)
what is a heterocyst?
special bacterial cell that helps capture nitrogen from the air and turn it into nutrients for other bacteria
true or false - bacteria break down waste and help plants grow
true
capsule is an important part in bacteria, what does it do?
protective layer outside the cell wall
what is the capsule made of?
polysaccharides or proteins
how does capsule play a role in the attachment to surfaces?
helps bacteria stick to surfaces to form colonies
how does the capsule help bacteria survive?
capsule makes it hard for white blood cells to attack the bacteria, helping it avoid being destroyed
how do fimbriae and pili help bacteria
they help bacteria stick to surfaces
which domain do eukaryotes share a common ancestor with?
archaeans
gram-positive
thick peptidoglycan
what colour stain in gram positive bacteria?
purple stain
gram negative
thin peptidoglycan
what colour stain is gram negative bacteria?
red stain
why are gram negative bacteria more resistant to antibiotics?
they have an extra outer membrane with lipopolysaccharides, which provides additional protection
why are some gram-negative bacteria harmful?
their lipopolysaccharides can be toxic
what is the structure of prokaryotic DNA?
small, circular chromosome with no nucleus
what are plasmids?
small, extra pieces of DNA that bacteria can share with each other
what are the three factors contributing to prokaryotic genetic diversity?
rapid reproduction, mutation, and genetic recombination
rapid production
bacteria divide quickly
mutation
changes in DNA happen more often, leading to new traits
genetic recombination
bacteria can transfer genes, sharing plasmids and gaining new traits
what is binary fission?
rapid asexual reproduction method where bacterial cell divides into two identical daughter cells
what are the three methods of genetic recombination in bacteria?
transformation, transduction, and conjuction
transformation
bacteria take in free DNA from their envrionment
transduction
viruses can transfer DNA from one bacteria to another
conjugation
bacteria directly swap DNA with each other
