First Test Flashcards
How do cells, the lowest level of biological organization arise?
they all arose by division of a previous living cell. all cells come from previous cells
6 parts of the hierarchy of life
biosphere, ecosystems, communities, populations, multicellular organisms, and cell
cell division
the process by which a parent cell divides creating 2 or more daughter cells
whats the purpose of cell division?
development, growth, repair, and reproduction
what are the types of cell division
mitosis and meiosis
which cell division produces genetically identical cells?
mitosis
growth and asexual reproduction happens via
mitosis
reproductive cells undergo which kind of division?
meiosis
what phylum is the sea buscuit from?
echinodermata
what is our closest intervertebrate relative
sea biscuit which is part of the echinodermata phylum
what structures play a role in cell division
cells, chromosomes, dna, genes
what are histones
proteins that are around the dna “beads on a string”
what are the proteins that are part of the dna
histones
genes
basic unit of heredity that code for specific traits
Ex. eye color gene
ploidy
number of pairs of chromosomes in a cell
polyploid
more than two pairs of chromosomes
each chromosome in a diploid cell is part of a
homologous pair
true or false:
homologous chromosomes may be different versions?
true
paternal cell
chromosome of a homologous pair coming from the male parent
maternal cell
chromosome of a homologous pair that comes from maternal parent
somatic cells
body cells except reproductive cells
gametic cells
reproductive cells
egg and sperm
somatic cells undergo what kind of division
mitosis
what cell division do gametes go through
meiosis
somatic cell:
parents cell divides to form how many daughter cells?
2
gametes:
parent cell divides to form how many daughter cells
4
crossing over
exchange of alleles between homologous chromosomes
fertilization
2 haploid cells coming together to form one (zygote)
how does a single individual rise to a complex, multicellular organism?
mitosis
how does an individual give rise to another, completely unique individual?
meiosis
fetilization to unite gametes
for sexually reproducing organisms, genetically distinct gametes produced via meiosis to unite at
fertilization
How does the zygote develop and grow?
through mitosis
random fertilization
combination of gametes
random genetic variation
- increases genetic variation
- raw material on which evolution acts
- the advantage of sexual reproduction
what allows a population to survive in changing environments?
genetic variation
In multicellular organisms, what does mitosis provide for them?
new cells for development, growth , regeneration, and repair
single celled organisms reproduce?
asexually via mitosis
-offspring are genetic ‘clones’ of the parent
in meiosis, how many chromosomes do they have?
half of the parent’s chromosomes so 23
life has existed for how many years?
3.6 billion years
how many species are on earth?
8.7 million
what do living organisms share that set them apart from nonliving matter?
a set of characteristics:
chemical instruction, engage in metabolic activity, energy flows through living organisms, they respond to change in the external environment, populations of living organims change from one generation to the next, and they reproduce and develop
what kind of chemical instruction do living organisms have
dna
how do living organisms engage in metabolic activity
metabolism like photosynthesis
how does energy flow through living organisms
through trophic levels
-producers to consumers
how much energy is passed on to the next trophic level?
10%
how do living organisms respond to change in the external environment
they detect environmental change and they compensate for change
they maintain stability of internal environment in responses to changes in external conditions
homeostasis
same state
how do populations of living organisms change from one generation to the next
through evolution
what are 2 important drivers of evolutionary change:
- selection for particular traits
2. occurrence of random favorable mutations
True or false:
if adaptive, particular traits/ mutations may not be passed on to offspring and may not increase in frequency within a population over time
false
how do living organisms deal with reprodcution and development
all able to develop in their own way
taxonomy
an early branch of science to identify , name, and classify species
binomial nomenclature
each type of organisms identified by 2 part scientific name
species
all individuals that have similar structure, biochemistry, behavior, and can interbreed to produce viable fertile offspring
genus
group of similar species that share recent common ancestry
taxonomic hierarchy
species, genus,family, class, phylums, kingdon,domain
what’s wrong with the taxonomi hierarchy traditional classification scheme?
its hierarchical, but it doesn not reflect evolutionary history
Darwin’s branching evolution
organims may be related to eachother through shared ancestry
phylogeny
evolutionary relationships
why do biologists construct phylogenetic trees?
to detremine relatedness and time elapsed since divergence from a common ancestor
how do biologists construct phylogenetic trees?
based on similarities in genetic sequences
what are the 3 main domains
eukarya, bacteria, and archaea
systematics
classifies biodiversity according to evolutionary relationships (phylogeny)
r———_______———-
what does r represent in a phylogenetic tree?
the root of the tree which is the common ancestor of all the terminal taxa in the tree
terminal taxa
the organisms whose relationships you’re trying to understand
taxon
any group that forms a unit interest
nodes
the most recent common ancestor of the taxa it connects; also where lineages diverse
lineage
a sequence of species that form a line of descent
divergence axis
the relative timing of splitting events; sometimes it is called “calibrated” to show absolute time
clade
a taxon that includes common ancestor and all of its descendants
2 taxa that are each others closest relatives are
sister taxa
dichotomous
either/ or
anagenesis
gradual change in a lineages over time
cladogenesis
evolution of an ancestor species into 2 descendant species
monophyletic taxon
comprises one clade- an ancestral species and all of its descendants
paraphyletic taxon
includes a common ancestor and some, but not all, of its descendants
polyphyletic taxon
includes taxa from different clades, but not their most recent common ancestor
homologies
traits similar due to shared ancestors
homoplasies
traits evolved independently in different lineages
homologous morphological traits are
- similar in anatomical detail
- originate from the same embryonic tissues and grow in similar ways
are wings in bats and birds homologous or homoplasies?
homoplasie
developmental
- earliest life stages of organisms may provide only evidence of its evolutionary relationships
- protostomes and deuterostomes
protostome
mouth first
deuterostome
mouth second
behavioral
- can be reliable indicators of relationships
- 2 different species of tree frogs used distinctive mating calls to attract females
molecular
-shared sequence of dna and rna used to infer evolutionary relationships
how can we identify the one phylogeny that shows the actual history of diversification?
cladistics
cladistic
classification system that infers diversification of species by comparing character states
synaomorphy
derived state shared by 2 or more taxa
-jaws, lungs, claws, scales, feathers
WHat might explain the close evolutionary relationship between birds and crocs?
shared derived behavior
-parental care
loss of complexity
some insects lost wings
-penguins lost their ability to fly
how do complex traits evolve
independently (homoplasies)
prokaryotes
- single celled organisms that lack a nucleus
- some cellular differences
some archaea are what?
extremophiles
extremophiles
organisms that like to live in extreme environments
eukaryotes
- includes animals, plants, fungi and protists
- may be single celled or multicellular in construction
bacteria and archaea have prokaryotes or eukaryotes?
prokaryotes
what are the shapes that prokaryotes may appear as
rods (bacillus) , spheres (coccus), spirals
where is the dna located in a prokaryote
nucleoid
the polysacchride capsule
- sticky
- allows prokaryotes to adhere to surfaces- coating microbial communities called biofilm
fimbriae
short hair like structures for attachingto substrates or to eachother
pili
long hair like structure for attahing to eachother to exchange genes
biofilm
bacteria produce a 3d extracellular matrix
why are biofilms important?
form and grow on any surface exposed to fluid
how do prokaryotes communicate
individuals detect and respond to chemicals released by other microbes
quorum sensing
system of stimulus and response correlated to pop density
how do prokaryotes reproduce
through binary fission
how does genetic variation in prokaryotic populations arise?
mutation, genetic recombination
the 3 ways prokaryotes can receive dna
transformation, transduction, conjugation
transformation
an individual picks up prokaryotic dna from the environment
transduction
a virus injects its dna into an individual bacterium
conjugation
a bacteria gets dna from another bacterium of the same or of a different species
bacterial cells connect via what
pilus
horizontal gene transfer
movement of dna between individuals od different species
true or false:
prokaryotes are not super diverse in morphology
true
true or false:
prokaryotes are not diverse in metabolism
false
autotrophs
make their own food (photosynthesis)
heterotrophs
must feed on organic matter from other organisms
photoautotrophs
carry out photosynthesis
photoheterotrophs
carry out photosynthesis and also eat
chemoautotrophs
energy source: chemical compunds like hydrogen sulfide
chemoheterotrophs
organic compounds made by or available in other organisms
pathogenic
disease causing
most pathogenic bacteria are gram + or -?
-
gram positive
- purple
- thick cell walls
gram negative
- disease causing
- thinner cell walls
- has capsule
actinobacteria
group of gram + bacteria, some exhibit elaborate branching
-tb is an example of one
staphylococci
pathogenic of gram +
-food poisoning
mycoplasmas
smallest cellular organisms known
clostridium
bacterium produces neurotoxin that causes botulism
botulism
paralysis and death
largest group of bacteria
all gram -
cyanobacteria
- gram - but not pathogenic
- helpful to the environment
chlamydia
cause of most stds
spirochates
borrelia, spiral shaped bacteria that can cause lyme disease
crenarchaeota
- archaea
- thermophilic
- some acidophilic
euryarcheota
- methanogens
- cows
halophiles
like salt
korarchaeota
genetically distinct from other archaea
nanoarchaeota
-only a few known
importance of prakaryotes
- key players in element cycling
- carbong cycling
- nitrogen cycling - important in symbiotic relationships
symbiosis
live together
what kind ofgram - bacterium was engulfed to become mitochondria?
member of proteobacteria clade
whats primary production
process of producing energy rich organic compounds from inorganic materials in the environment
phytoplankton
phyto- plant plankton- wanderer
phytoplankton produces most of the worlds?
oxygen
zooplankton
zoo- animal plankton-wanderer
in moist terrestrial soils, protists are important
decomposers
-slimemolds
parasitic
living on or in a host organism
-spirochonda
endosymbionts
inside living together
dinoflagellates
endosymbionts of corals
causes of harmful algal blooms
excess of nutrients (nitrogen and phosphorus)
what causes malaria
plasmodium
bikonta
2 flagellae
unikonta
1 flagella
rhodophyta
red algae
use chlorophyll as main photosynthetic pigment
mostrly marine
nori
seaweed
agar
polysaccharide
chlorophyta
green alage
-photosyntheic pigments a and b
coencytic
one giant cell
chromalveolates
includes 2 clades:
stramenopilia, alveolatas
stramenophiles
from unicellular diatoms to giant multicellular kelp
alveolata
unicellular microscopic dinoflagellates
bacillariophyta
diatoms are microscopic, unicellular photoplankton
-primary producers in aquatic habitats
pnematocysts
gas bladders in large blades of kelp
trumpet cells
elongated cells joined end to end transport photosyntates through kelp
dinoflagellates
90% are marines
micro organisms
amoebas
- unicellular w/lobe shaped pseudopods
- mostly heterotrophic
slime molds
amoeboid-like protists aggregate to form complex multicellular structures
opisthokonts
eukaryotic clade that includes fungi, animals, and protists
choanoflagellates
-aquatic
-unicellular (some capable of forming colonies)
-sister of all animals
sister taxa of all animals
