Intro Module Ch1,25 Flashcards
What is biology
the study of life
what properties does life depend on?
order (structure), evolutionary adaptation, regulation, reproduction,, response to the environment, growth, and development, energy processing
what is coevolution
close interactions between different species sculpted genetic information to produce compatible traits
levels of biological organization
1)biosphere 2)ecosystem 3)communities 4)populations 5)organisms 6)organs 7)tissue 8) cells 9)organelles 10)molecules
reductionism
reduces complex systems to simpler components at are more manageable to study (can provide incomplete view)
emergent properties
new properties that arise with each step up hierarchy of life, owing to the arrangement and interactions of parts as complexity increases
what is every cell enclosed by
a membrane that regulates the passage of materials between the cell and its surrounding
what are the two main forms of cells
prokaryotic and eukaryotic
what two groups of single celled organisms are prokaryotic cells found in
bacteria and archaea
what do eukaryotic cells contain
membrane enclosed organelles
what is found in the cells of all eukaryotes
DNA containing nucleus
what are all forms of life composed of (plants, animals)
eukaryotic cells
chloroplast
organelle found only in eukaryotes that carry out photosyntheis
what do prokaryotic cells lack
a nucleus or other membrance encolsed organelles, smaller than eukaryotic cells
what cell is this
eukaryotic cell
what cell is this
prokaryotic cell
chromosomes
info within cells, contain genetic material in forms of DNA (deoxyribonucleic acid)
1 chromosome=one long strand of DNA = tons of genes
what are genes
unit of inheritance
DNA
made of strands (two long chains) arranged in double helix
each chain = 4 kinds of chemical buikding blocks (nucleotides)
1)A 2)T 3)C 4)G
how do protein encoding genes control proteins indirectly
using RNA
what is a sequence of nucleotides along a gene transcribed into? What are they then translated to
mRNA
linked series of protein building blocks called amino acids
gene expression
process by which info in a gene directs manufacture of a cellular product
what protein helps lens of an eye to focus
crystallin
what causes differences in organisms
nucleotide sequences not genetic code
what is evidence for all life is related
genetic code
genome
library of genetic instructions an organism inherits
genomics
molecular bio about structure, function, evolution +mapping of genomes
proteome
entire set of proteins expressed by given cell, tissue, or organism
how does energy typically leave an ecosystem
as heat
what are three groups of organisms
1)bacteria 2)archaea 3)eukarya
how do you read a phylogenetic tree
-each node is a species
-dagger symbol means extinct
what drives evolution
large scale processes such as geological processes ie pangea
adaptive radiation
groups of organisms (eg mammals) for many new species who adaptations allow them to fill different ecological roles/niches
for fossil record
old stratum at bottom young stratum at top
what can all life be traced back to
origin of unicellular organisms in the ocean
called stromatolites
what era is most of our fossil history found
Phanerozoic
memorize, each hash is 250 million years
what similar trait to first organisms has been inherited by present day organisms
info flows from the genome to physical traits or phenotypes
atmospheric oxygen
-around 2.7 billion years ago
-altered atmosphere creating new challenges and opportunities for evolving life
-was toxic for a lot of cells in beginning
photosynthesis and oxygen revolution
-many prokaryotes went extinct and others lived in anaerobic environments, others adapted
-goes essentially from 0% to 100% similar levels of oxygen in earths atmosphere to today
-substantial increase of oxygen bc of photosynthesis
-wobbly parts is because of ice age/glacial periods
how did eukaryotes originate
by endosymbiosis of a prokaryotic cell which evolved into a mitochondrion
what did compartmentalization by organelles lead to
increased cell size, complexity and metabolic efficiency
what was endosymbiont able to utilize
oxygen and could have been a prey or parasite of the host prokaryote which was likely an Archean. eventually, the relationship became mutually beneficial and evolved into a single celled organisms
endosymbiosis
ingestion of this bacterium
when did first eukaryotes occur
2 billion years ago
what did cooperation between single celled eukaryotes eventually lead to
multi cellularity
how did cells with aggregates begin to express their genetic info
differently giving rise to distinct types of tissues
What are some of the oldest multicellular eukaryotic fossils
red algae from 1.2 billion years ago
first plants and animals when? what were they?
600 mya
-ediacariam biota: soft bodies invertebrates animals
when was cambrian explosion
between 535 and 525 mya
what occurred during Cambrian explosion
-predator prey interactions:evidenced by offensive (claws) and defensive adaptations (body armor)
-diverse body plans
what were animals like before cambrian explosion
grazers, filter feeders or scavengers
colonization of land when
500 mya
what first began to colonize land
fungi, plants, animals
-fungi in plants had symbiotic relationships
what does evolution of vascularization allow plants to do
spread throughout terrestrial environments
what colonized land next (beside fungi and plants)
anthropoids and tetrapods (most diverse and widespread land animals)
what is a tetrapod
4 limbed animals such as humans
how does diversification happen
adaptations
what helped plant reproduction
seed dispersion
when were first humans
195,000 ya
when and what did human lineage diverge from
primates 6-7 mya
how much DNA do we share with chimps and great apes
98%
what are large scale processes that cause changes over time
-continental drift
-mass extinction
-adaptive radiation
what does continental drift do to species
organisms are under constant pressure to adapt to ever changing habitats
organisms have ti adapt to changing geology
what can separation of land masse cause
lead to speciation through isolation
what do fossil records show about past species
that most species that have ever lived are now extinct
how many mass extinctions have occured
five
-x-axis is time
-y-axis is total extinction rate
-secondary y-axis shows number of families that are present
-peaks in red lines are associated with mass extinction events, decline in blue line families constantly
in each mass extinction how many marine species became extinct
50% or more
when was origin of earth
4.6 billion years ago
when was first prokaryote cell
3.5 billion years ago
