Biosphere Flashcards
The production of biomass/ organic matter by autotrophs can be viewed as both:
1. ___ production=
2. ___ production=
- gross production= the production of organic matter before any use
- net production= stored biomass that remains after metabolism
Heterotrophs:
- ___ other organisms
- use that organic carbon for ___ (obtains energy)
- use the remainder to build ___ mass (____ production)
Heterotrophs:
- consume other organisms
- use that organic carbon for respiration (obtains energy)
- use the remainder to build body mass (secondary production)
population=
multiple individuals of one species living in the same area at the same time
communities=
interacting populations of different species
a community plus its associated non-living system (soil, air, water, etc) forms an ___
ecosystem
similar ecosystems are grouped into classes called ____ where the climates, habitats, and ecosystems are similar
eg
biomes
tropical rainforest biome
the ___ ____ of a species indicates how many feeding steps it is away from the autotroph level
trophic levels
feeding relationships form a food chain, which is the transfer of ___ and ___
energy and matter
The organic carbon and energy captured by autotrophs in an ecosystem is ___ ____ _____
- typically, 25-75% of organic carbon is ____ by these autotrophs
- remaining, stored organic carbon is ___ ___
gross primary production
respired
net production
net production = ___ ____ - ____ ____
net production= gross production- net production
-
- decomposers
- the next trophic level
typically, each trophic level receives about ___% of the productivity of the previous one
10%
each organism in an ecosystem is said to occupy a distinct ___ ____, defined by its habitat and position in the ___ ___
ecological niche
food web
if two organisms occupy the same ecological niche in an ecosystem, one typically eliminates the other. This goes back to the idea of actualism (probably happened in the past too)
what is this defining?
competition
the ocean has a huge area, so high ___ production
the tropical rain forests don’t have a huge area, but have very high ___and ___ production
primary
primary and net
explain provinciality
barriers to animal migration have resulted in regions with distinct faunas and floras
- a single biome can exist in multiple provinces but is populated by different species
areas with provinciality are known as:
_____ zones or _____ provinces or ______
biogeographical zones
biogeographical provinces
ecozones
give a modern example of provinciality
anteaters exist in the rainforest biome on several continents
- these occupy the same niche in the biome but occur in separate provinces
(they evolve b/c of restrictions to migration)
give an ancient example of provinciality
Cambrian trilobites show different faunal provinces
- on either side of an ancient ocean
- also one of the earliest evidence for plate techtonics!
prokaryotes:
- ___ celullar
- no distinct ___ or ____
- includes ___ and ______(blue-green algae)
unicellular
nucleus or organelles
bacteria and cyanobacteria
T/F
when we look at the history, it’s hard to see a distinction in when prokaryotes and eukaryotes evolved
false!
prokaryotes first
eukaryotes:
- ___ or __ cellular
- have an outer ___
- contain ___ and a distinct ____
multicellular or unicellular
outer membrane
organelles and distinct nucleus
why is the process of cell division so important?
it allows:
- unicellular organisms to reproduce
- multicellular organisms to grow
-
polymers
- proteins
- nucleic acids
____ are polymers that make the structure of cells and organelles
The __-__ bond is essential to the structure
proteins
C-N
RNA (ribonucleic acid) forms on the __ template and carries information from DNA to the sites of ____ ____ (___)
DNA template
protein formation (at the ribsomes)
some elements break up biological polymers and interfere with their ___
= ____
function
= toxins
What are the big 6 macronutrients required by all living things in large amounts?
C- carbon
H- hydrogen
O- oxygen
N- nitrogen
P- phosphorous
S– sulfur
micronutrients=
small amounts required for all life, or required by only some living things
toxins=
detrimental to living organisms
Each element is involved in a _____ cycle
- the cycle may take the element through the ___, ___, and/or ___
- each nutrient can become a ___ ___ for life
biogeochemical
- geosphere, hydrosphere, and/or hydrosphere
- limiting factor
nitrogen must be in a ___ form to be useful (living things use ___)
nitrogen exists as ___ in the atmosphere
reduced form- ammonium
N2 gas
explain the main 2 ways that atmospheric nitrogen is fixed (reduced) into useable form
- Lightning- provides a small amount
- Nitrogen Fixing Bacteria
- live in root nodules of certain plants (symbiosis- provide them with fixed N and get protected from O)
- evolved in early earth (no O2)
Denitrification:
bacteria that use fixed nitrogen as an oxygen source, return N2 to atmosphere
NO3- or NO2- to N2
variability of the biosphere is ___
(divided into ___ species)
discontinuous
discrete
The species concept states that:
- individuals in a species have many ___ in common
- individuals of the same species can ___ successfully and their offspring are ___
- variation __ a species is much less than variation __ a species
characteristics
interbreed, fertile
within is less than between
DNA is organized into ____, each of which codes the formation of a different ___
genes
protein
all species show ____, which is primarily driven by __ at the molecular level
variation
mutations (passed on to later generations)
due to ___, many individuals die before maturity
competition
“strongest survive”= natural selection
-offspring that survive to maturity are best suited to their enviro
- enviro selects those ___ to give the best survival chances
= the enviro applies ____ ____
variations
selection pressure
other selection pressures can come through ____ change
example:
environmental change
eg. black moths in london during industrial revolution
one species can split into 2 or more when populations become ______ ____
example:
geographically isolated
eg. Darwin’s finches
genetic drift=
differences in genetic makeup that don’t impact survival (geographical barrier)
evolution by natural selection was independently discovered by ___ ___ and ___ ___ ___ in the mid-1800s
Charles Darwin
Alfred Russel Wallace
What are the 4 Eons (from most recent to oldest)
- Phanerozoic (most recent)
- Archean
- Proterozoic
- Hadean (oldest)
What are the 3 Eras within the Phanerozoic Eon (from most recent to oldest)
- Cenozoic (most recent)
- Mesozoic
- Paleozoic (oldest)
what’s one reason for bias in the geological record of fossils?
most fossils only preserve the hard parts (skeletons etc) of the organism
- no soft-bodied organisms are preserved/ recorded
the earliest stages in evolution likely involves polymers combining without ___ ___ ___
This probably occurred in the ___ and ___
surrounding cell membranes
Hadean and Eoarchean
the first prokaryote cells: ___ billion years ago
- no oxygen, so they were _____
3.5
chemosynthetic
early cells gained energy by ___ reactions (____ respiration)
- produces much less energy than _____ respiration, but it worked
fermentation
(anaerobic)
aerobic
oxygen was ____ to early organisms because it’s so reactive
How did they dispose of any oxygen?
poisonous
-used reduced elements like Fe2+ dissolved in sea water- converted it to oxidized iron (Fe3+)
- lots of Fe3+ in the oceans at this time!
what was the first photosynthetic organism?
stromatolites (“algal mats”)
- in limestone: built by photosynthetic prokaryotes (cyanobacteria)
- primitive life forms, still exist
The Great oxygenation event was ___ to ___ billion years ago, and resulted in thick deposits of _____ (which created the ___ ___ ___)
2.4-2.0 billion years ago
hematite (Fe2O3) because there was widespread oxygenation of Fe2+ into Fe3+
Banded Iron Formation (BIF)
What allowed for eukaryotes to start developing larger body sizes?
they evolved to protect themselves from free oxygen in water= allowed for much more efficient aerobic respiration
Eukaryotes may have originated from ___ ___ ___ (heavily debated)
combinations of prokaryotes
The Cambrian Explosion was ___ - ___ million years ago
541-485
-
-
- the rapid appearance of diverse multicellular animals related to present-day phyla (trilobite)
- evolution of a gut
- evolution of shells for defense against predation
When did plants and animals start appearing on land?
around 420 million years ago
mid Paleozoic era
what may have produced peak atmospheric oxygen levels in the mid Paleozoic era?
start of the tropical rainforest as more plants moved to land (more photosynthesis= more O2)
The ___ era is known as the “age of reptiles”
- produced widespread land chordates (inc ____)
- earliest mammals and ____ plants
- ended at
Mesozoic era
dinos!
flowering
major extinction event (impact at Chicxulub in Mexico)
Major extinction events change the ____drastically and instantly
- as a result, they tend to be followed by:
biosphere
appearance of new taxa (=ADAPTIVE RADIATION)
In what era did mammals rise after the mass extinction?
Cenozoic era (66 million years ago)
