Exam 2 Flashcards
Intact fossil
forms when decomposition does not occur and the organic remains are preserved and intact
Compression fossil
forms when sediments accumulate on top of the organism and become cemented into the rock
What must occur for fossil creation?
organisms must die in an environment where they are buried rapidly and decompose slowly
Habitat bias
Organisms that live in areas where sediments are actively being deposited are much more likely to form fossils. Burrowing organisms are already underground at death and are therefore much more likely to fossilize.
Taxonomic + tissue bias
Organisms with hard parts are most likely to leave fossil evidence. Similarly, some tissues fossilize more readily
Temporal bias
Recent fossils are much more common than ancient fossils.
Abundance bias
The fossil is weighted toward common species.
Precambrian
Interval between the formation of Earth (4.6bya) and the appearance of most animal group (541mya)
Phanerozoic era
The interval between (541mya) and today
Paleozoic
-appearance of most major animal lineages + ends with the obliteration of almost all multicellular life
-initial diversification of animals, land plants, + fungi
-appearance of land animals
Mesozoic
-begins with extinction + ends with extinction of the dinosaurs (except birds)
-gymnosperms were dominant on land
-dinosaurs were dominant vertebrates
Cenozoic
-flowering plants dominate land
-birds and mammals dominate vertebrates
What is the order of the 3 phases of the phanerozoic era?
Paleozoic –> Mesozoic –> Cenozoic
Adaptive radiation
when a single lineage rapidly develops many different lineages with different adaptations for different niches
The Cambrian Explosion
a massive explosion of life that included soft-bodied animals diversifying to include hard-bodied animals
What are two of the main theories surrounding the Cambrian explosion?
-an increase in O2 in the Earth’s atmosphere
-Hox genes allowed the rapid development and inheritance of many genes that code for complex traits
Mass extinctions
result from extraordinary, sudden, & temporary changes in the environment.
Background extinctions
occur when normal environmental change, emerging disease, predation pressure, or competition reduces certain populations to zero.
Cast fossil
forms when a buried organism decomposes, leaving an empty cavity in the sediments that fills with dissolved minerals and hardens into an accurate cast of the remains (ie. shells)
Permineralized fossil
forms when organisms decompose extremely slowly. dissolved minerals gradually infiltrate the interior of the cells and harden into stone (ie. petrified wood)
Trace fossil
forms when sedimentation and mineralization preserve indirect evidence of an organism in an environment (ie.footprints, burrows, feeding marks, feces)
What are the two prokaryotic domains?
bacteria + archaea
Who proposed the 3 domain tree of life?(current theory)
Woese
Bacteria has ____ type(s) of RNA polymerase, which consists of ___ subunits.
1, 5
Archaea has ____ types(s) of RNA polymerase, which consists of ____ subunits. It is similar to ______ in _______.
1, 13
-RNA polymerase II, eukaryotes
Do bacteria have peptidoglycan in their cell walls?
yes
Do archaea have peptidoglycan in their cell walls?
no
Do bacteria have histones associated with their DNA?
no
Do archaea have histones associated with their DNA?
yes
Histones
proteins that help keep DNA untangled
Lateral gene transfer
the transmition of genetic material not by inheritance
Prokaryotes are the ____ and most ____ lifeform on Earth.
oldest, abundant
Prokaryotes are found ____ with _____.
everywhere, biological life
The first prokaryote was in domain ____.
archaea
Was the first prokaryote aerobic or anaerobic?
anaerobic, there was no abundant atmospheric oxygen on early Earth
_____ are organisms that live in extreme environments.
extremophile
The first life on Earth would have been an ______ and ______, in domain ______.
extremophile, prokaryote, archaea
What is so important about the prokaryote ‘Thermus aquaticus’?
the DNA polymerase that is produced by this bacteria is used to amplify DNA over and over, very rapidly. (ie. pcr, paternity tests, forensics)
DNA polymerase
an enzyme that catalyzes the synthesis of DNA molecules
Bacteria that cause illness are called _____.
pathogens
Families of harmful bacteria are derived from ____ lineage(s).
different
The ability to cause disease is _____.
virulence
In virulence genes: one gene is a ____ ____ - it binds to ____ and inhibits ____ ____, killing the host cells.
-protein toxin
-ribosomes
-protein synthesis
Some pathogenic _____ produce resistant ______- tough, thick-walled, dormant structures formed during times of _____ stress.
-bacteria
-endospores
-environmental
Endospores store _____.
key genetic information (ie. DNA, RNA, enzymes)
Describe DNA transfer by transformation
- dead cell releases DNA into the environment
- donor DNA taken up by host
- new DNA incorporated into host DNA through recombination
Describe DNA transfer by transduction
- bacteriophage infects host (donor), which produces phages with a combination of both viral and bacterial DNA
- dead cell releases bacteriophages into the environment
- virus infects donor DNA into host
Describe DNA transfer by plasmid transfer, conjugation
- bacterial cells make contact
- copy of a plasmid from one cell is transferred via a conjugation tube
Describe DNA transfer by recombination, conjugation
- portion of main chromosome is copied and transferred through conjugation tube to recipient cell
- transferred portion recombines with chromosome in recipient cell
The first forms of photosynthesis didn’t release ____. Instead they used ______ as an electron donor.
-O2
-Hydrogen sulfide
bacillus
rod shaped bacteria
cocci
sphere shape bacteria
spirilla
spiral shaped bacteria
Bacteria have a unique compound called ____ in their ____.
-peptidoglycan
-cell walls
Gram-positive bacteria stain ____.
purple
Gram-negative bacteria stain ____.
pink
What part of the bacteria stains in a gram stain?
the peptidoglycan
Why are gram-negative bacteria harder to kill with antibiotics?
They have two cell membranes
Where do phototrophs get their energy?
sunlight
Where do chemoorganotrophs get their energy?
organic molecules
Where do chemolithotrophs get their energy?
inorganic molecules
Fermentation is ____ effective that cellular respiration. And ____ evolve the ETC.
-less
-doesn’t
The only lineage of photosynthetic bacteria that produces O2 is _____.
cyanobacteria
The evolution of cyanobacteria led to the creation of the ____ and threw the Earth into the _____.
-ozone layer
-ice age
Protists include all ____ except, ____, ____, & ____.
-eukaryotes
-land plants
-fungi
-animals
Are protists a monophyletic group?
no
Fungi are more closely related to ____ than ____.
-animals
-plants
_____ likely evolved multiple times in eukaryotes.
multicellularity
Are protists multicellular or unicellular?
they can be both
During endosymbiosis the host cell provided ___ & ____, while the bacterium provided ____.
-protection
-carbon compounds
-ATP
What evidence suggests mitochondria were once independent?
-same size and similar gene sequence as _____
-replicate by ____
-have their own ____ & manufacture their own ____
-have _____ membranes
-have their own _____
-α-proteobacteria
-fission
-ribosomes, proteins
-double
-membranes
Secondary endosymbiosis
The engulfing of a cell that has previously been engulfed (membranes X4)
All species in the ____ have chloroplast with ____
-Plantae
-2 membranes
Chloroplasts occur in ___ other lineages of protists. (other than Plante)
4
How did the nuclear envelope form?
-infoldings of the plasma membrane surrounded the chromosomes
-with the evolution of the eukaryotic cell, membranes fold and form the nuclear envelope & ER
Sexual reproduction is unique to ____.
eukaryotes
Alternation of generations
multicellular haploid & diploid forms look identical
The sporophyte phase (_) produces ____.
-2n
-spores
The gametophyte phase (_) produces ____.
-n
-gametes
Harmful algal ‘blooms’ can be caused by ____.
dinoflagellates
What is the most ancestral group of plants?
green algae
Plant life started in ____.
water
The first green plants in the fossil record are ____, and were found in rocks from the ______ period.
-green algae
-precambrian
What 2 traits do all plants discussed have in common?
-chlorophyll A&B
-starch for storage
first land plants: from ___-___
475-416mya
non-vascular land plants include ____
liverworts, hornworts, & mosses
Why do we know so much about the first land plants?
the produced spores with fossilized really well
The green algae that are most closely related to land plants have ____ dominant life cycles. And no ____.
-haploid
-alternation of generations
____ is a very durable biopolymer that encases spores & prevents dying
Sporopollenin
____ are complex, multicellular structures that protect developing games from drying & physical damage
Gametangia
Nonvascular land plants are ____ dominant.
gametophyte
Land plants exhibit ____
alternation of generations
Eggs develop in the ____
archegonia
Sperm develop in the ____
antheridia
Seedless-vascular plants have a ____ dominated life cycle. They are commonly known as ____.
-sporophyte
-ferns
The evolution of ____ gave plants more support and allowed them to grow taller.
lignin
Does mitosis or meiosis make spores?
meiosis
Name two examples of gymnosperms.
pines and ginkgo trees
What are the two classifications of angiosperms?
monocots and dicots
angiosperms are the most ____ plants and most ____ diverged.
-diverse
-diverged
which taxon has flowers and fruits?
angiosperms
The ____ is the location of the egg and is found in _____.
-ovule
-angiosperms & gymnosperms
The ____ is the extra layer of protection around the egg and is found in ____.
-ovary
-angiosperms f
____ plants are heterosporous.
seed
The microsporangia produces microspores, which is the ___ gametophyte.
male
The megasporangia produces megaspores, which is the ___ gametophyte.
female
____ is a male gamete surrounded by sporopollenin.
pollen
seed plants are ___ dominant
sporophyte
Malaria is caused by 5 species of ____.
plasmodium
What are the stages of a malaria infection?
-bites human
-liver cells infected
-replicate in liver cells until they burst
-infect red blood cells
-replicate in blood cells until they burst
-bites human
-male and female gametes release and fuse to form a zygote
-infected mosquito bites another human
