test 2 Flashcards
When viewing life our current view consists of what 3 domain ?
Bacteria, Archaea , Eukaryotes
How do we define what a living thing is?
Organisms that typically have the capability to grow, reproduce, respond to stimuli (metabolize) and maintain homeostasis.
What are three shared characteristics of all living things?
More than one cell, metabolism, has transferable heritable information
Do viruses satisfy criteria for characterizing life?
Viruses are on the cusp of life they do not meet all criteria
Do Archaea or Bacteria have a nucleus?
No
most eukaryotes have membrane bound organelles and this can be true for Archaea and Bacteria as well
true
what is endosymbiosis?
the bringing together of two distinct cells inside another
how would you describe the endosymbiotic theory?
theory stating that eukaryotes may have been a product of one cell engulfing another eventually they evolve into a relationship where they rely on each other to survive.
All the DNA in eukaryotic cells is located in the nucleus? T/F
False, it can be in the mitochondria as well for example.
what is polytomy?
family tree splits into 3 or more branches a the same time
Defining characteristics of Eukaryotes is the presence of:
A nucleus and a mitochondria
mitochondria in all eukaryote lineages have a common ancestor true/false
true
All photosynthetic organisms are Eukaryotes? T/F
false cyanobacteria is an example of a photosynthetic prokaryote
what are characteristics of first primary endosymbiosis?
-All eukaryotes
-refers to mitochondrion
-evidence to show it only happened once in tree of life
what are characteristics for Second primary endosymbiosis
-Does not occur for all eukaryotes
-refers to endosymbiosis of photosynthetic bacterium(chloroplast)
-the process has happened many times independently
All eukaryotes have a chloroplast and sometimes have a mitochondria T/F
F
where did photosynthetic metabolism first occur?i
in bacteria called cynobacteria
what is acquired through endosymbiosis
chloroplasts and mitochondria
how are chloroplasts different from mitochondria when thinking of eukaryote lineage?
chloroplasts are result of separate endosymbiosis events
what are three mitochondrial DNA characteristics?
-circular or linear and lineage dependent
-can exist as a single copy or many per cell
-similar to many bacterial DNA
regarding mitochondrion structure what is cristae
fold in inner membrane where electron transport chain takes place and it is lineage specific
how can chloroplast structural diversity relate to mitochondria diversity
extremely diverse with overall structure
monophyletic vs non monophyletic
monophyletic has all the descendants from a common ancestor while non monophyletic does not
what is supergroup excavata
diverse group of single celled/unicellular organisms that are mostly found in anaerobic environments.
what are supergroup Chromalveolata
large group of single celled organisms with distinct features and ecological roles examples include
brown algae- support entire ecosystems
golden algae-
diatoms
what are supergroup rhizaria? what is an example?
large group of single celled organisms with special extensions for movement and feeding.
foraminiferans is an important example
how much carbon is within life on earth?
550 gigatons
rank bateria, fungi, plants, animals from largest terrestrial biomass to smallest
plants, bacteria, fungi, animals
what are Archaeplastida and what do they contain?
Supergroup of eukaryotes
red algae
chlorophytes
charophytes
land plants
what is green algae
have chloroplast that contain green pigment called chlorophyll a and b aiding photosynthesis
how would you define chlorophytes?
unicellular and multicellular, ocean aquatic
how would you define charophytes?
unicellular multicellular, many found in freshwater, closely related to land plants
what are challenges of moving from a freshwater aquatic habitat to a terrestrial land habitat for plants`
avoiding water loss in cells
loss of support from water making it stand up
developing ways to pass genetics
acquiring resources
what are benefits of moving from freshwater to terrestrial land habitat
more light so more photosynthesis
higher concentration of minerals