Homework questions Flashcards
If prokaryotes did not exist, what would change in the nitrogen cycle?
The rate of movement of nitrogen atoms through ecosystems would be much slower
This is because prokaryotes facilitates many steps of the nitrogen cycle
What is the electron acceptor for humans in the electron transport chain?
Oxygen
Autotrophs
Create their own nutrients and energy
Heterotrophs
cannot synthesize organic molecules from inorganic sources and must obtain organic material by consuming other organisms.
Chemoautotrophs
need only carbon dioxide as a carbon source and obtain energy by oxidizing inorganic substances.
Photoheterotrophs
use light to generate ATP but must obtain carbon in organic form.
Chemoheterotrophs
must consume organic molecules for both energy and carbon.
Phototrophs
The general term for organisms that obtain energy from light
Chemotrophs
The general term for organisms that obtain energy from chemicals
Metagenomic analysis
Technique to isolate, observe, and study microbial DNA present in any environment or biological sample
What has metagenomic analysis allowed researchers to do for the first time?
study organisms that cannot be cultured (grown in the lab)
The important primary producers in marine ecosystems with cellulose cell walls are _____.
dinoflagellates
dinoflagellate
a single-celled aquatic organism with two flagella.
endosymbiosis theory for the origin of the mitochondrion
holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells are descended from formerly free-living prokaryotes
What advantage do organisms that reproduce sexually have over organisms that reproduce asexually?
Their offspring may be more adaptable to changes in the environment.
Which structure mediates the attachment of spores to a surface on which to grow?
Holdfast as it attaches spores to surfaces which it can grow
Where are the microsporangium found in a tulip?
stamen
Where are the megasporangium found in a tulip?
ovule
Describe how green plants affect the abiotic environment in ways that are advantageous to humans.
Plants release oxygen that we breathe.
Plants increase water supplies that humans can use for drinking, irrigation, or industrial use.
Plants build soils required for human agriculture and forestry.
Plants hold soils required for human agriculture and forestry.
Angiosperms are most closely related to _____.
gymnosperms
_____ are an example of seedless vascular plants.
Ferns
The living plants that are most similar to the first plants to bear gametangia are the _____.
bryophytes
charophyceans
class of green algae commonly found in fresh water
Related to land plants the most
Byrophytes
nonvascular plants that reproduce by spores and do not have flowers or seeds