2nd semester exam review Flashcards
what happens during crossing over
homologous chromosomes exchange segments of DNA during prophase 1
what’s the difference between haploid and diploid?
haploid has 1 set of chromosomes
diploid has both sets of chromosomes
during what phase of meiosis do tetrads form
prophase 1
what is the end product of meiosis
4 haploid cells (gametes)
what is a tetrad
4 sister chromatids formed by chromosomes lining up in synapsis
what is the law of independent assortment
it states that genes for different traits can segregate independently during formation of gametes
what is polygenic inheritance
inheriting a trait that is controlled by more than one gene (skin color)
what factor influences the change in color in the arctic fox
environmental factors (temperature, terrain)
which generation did Mendel allow to self pollinate
F1 generation
what type of trait is blood type
multiple alleles (controlled by 2 alleles)
what was Roland franklins contribution to the discovery of DNA
she worked independently with X-ray diffraction which helped contribute to Watson and crick’s discovery of DNA being a double helix
what is a codon
in mRNA it codes for a specific amino acid
consists of 3 nucleotides
what is DNA replication
replication of DNA where the strand separate and appropriate base pairs are plugged in
what does the mRNA copy
the recipe from DNA so proteins can be made
who figured out the shape of DNA
James Watson and Frances crick
what is the role of tRNA in protein synthesis
it transfers amino acids to the ribosomes
what is the function of telomerase
in rapidly dividing cells it helps to prevent damaged or lost genes
what happens during translation
tRNA translates the genetic code by delivering amino acids to the ribosome
anti codons pair with codons
codons come along to form long chains
where does translation and transcription take place in eukaryotes
translation- ribosome
transcription- nucleus
what was chargaffs contribution to the study of DNA
he discovered that the % of guanine and cytosine were almost equal in any DNA sample (adenine and thymine also) which led to the principle of base pairing
what is a promoter
regions of DNA with specific base sequences
where RNA polymerase binds to
what is a bacteriophage
a kind of virus that infects bacteria
can codons code for the same amino acid
yes
what kind of cells are used to make dolly
cloned cells (nucleus is removed & another is inserted into egg)
what does a karyotype show
it is a microphotograph of the chromosomes during cell division
ow does a person inherit PKU
if they inherit the autosomal recessive allele found on chromosome 12
can an offspring survive without at least 1 X chromosome
no, it contains over 1000 genes which many are essential for life
what is PCR
polymerase chain reaction
process used to make copies of a DNA sample
requires primer, thermocycler, DNA polymerase, nucleotides
what is recombinant DNA
DNA produced by combining DNA from different sources
what is a disadvantage of inbreeding
there’s a reduction in the genes pool and organisms are more susceptible to diseases
why is colorblind ness. more common in males
the genes for color visions are located on the X chromosome, but males are XY
it is recessive and affects 2 females 1 male
what is the role of primers in PCR
they are small sections of DNA that bund at 2 points of the sample, showing where polymerase starts and stops
what is the function of restriction enzymes
they cut DNA into fragments
create different enzymes
help cut up viral DNA so it’s easier to work with
how do some drugs result in polyploidy plants
they prevent chromosome separation during meiosis which produce polyploid plants
is achondroplasia dominant or recessive
dominant
what is hybridization
a breeding technique that involves crossing dissimilar individuals to bring together the best traits of both
what is behavioral isolation
reproductive isolation when 2 populations develop differences that prevent them from breeding
what type of population will be affected more by genetic drift
small population because allele frequency is affected
what does similarities in embryonic development support
evolution because they have similar developmental features
what are analogous structures
they aren’t made of the same tissue, but have the same function (doesn’t support common ancestry)
if the allele frequencies in a population change what is occurring
genetic drift
what is divergent evolution
when similar objects or species become different overtime
what are the conditions for maintaining genetic equilibrium
there must be random mating
large population
no migration
no natural selection
what is survival of the fittest
The organisms that are able to survive and have offspring are more likely to live
what adaptation did Darwins finches show
they had different beak shapes depending on the diet and adapted to the different food types in their different environments
what is a vestigial organ
they were used to do something but don’t anymore (appendix)
what is stabilizing selection
A form of natural selection where individuals at the center of distribution have a higher level of fitness than individuals at the edge of distribution curve
what do hox genes control
they determine which parts of the body develop and size (arms and legs)
what is geographic isolation
occurs when organisms can’t come in contact with each other
two different environments can choose two different traits
what is directional selection
when the environment chooses one extreme form over another (bird beaks)
what is the founder effect
change in allele frequencies as a result of a small subgroup migration from a population
what is temporal isolation
when organisms reproduce at different times
what is co-evolution
when one organism evolves in response to another
what does cladistic analysis show about organisms
how they are related based on shared and derived characteristics (hair)
Who developed the first classification system
carolus Linnaeus
what is systematics
The study of the diversity of life and organism evolutionary relationships
why are common names confusing
they vary from language, country, and region
Scientific names can be more specifically identified worldwide
what is binomial nomenclature
The standardized naming which is genus species, Latin or Greek, italicized, capital Genus only
what to taxa make up the scientific name
genus species
how are bacteria and archaea different
bacteria has no nucleus, cell walls contain peptidoglycan, they are autotrophs and heterotrophs, are aerobic and anaerobic, and contain eubacteria members
Archaea contain peptidoglycan, are found in oxygen lacking environments, and contain Archaea bacteria members
where do archaea
some of the most harsh environments lacking oxygen
which kingdoms contain eukaryotes
domain eukarya
Lissa levels of organization from broadest to most specific
domain, kingdom, phylum, class, order, family, genus, species
what was Oparin’s hypothesis
he hypothesized that gases went under chemical reactions in oceans, then lightning struck to create life
what does bipedal mean
being able to walk on 2 feet
why were there no oceans on primitive Earth
Earth formed as a molten mass with a temperature too high for water
what is half-life
The amount of time it takes for half of a radioactive sample to decay
did DNA or RNA come first
RNA because it is simpler
can help replicate DNA
it is a catalyst
it can replicate itself
our proteinoids similar to cells
they have selectively permeable membranes which water can pass through
budding
binary fission
osmotic swelling and shrinking
what kind of information can be gathered from fossils
The organism structure diet predators environment (life has changed)
why is homo habilis called the handy man
they were the first to use tools
what kind of rock are most fossils formed in
sedimentary rock because the sediment is transferred by water
what happened during the Cambrian explosion
organisms developed hard parts and they were inverts such as jellyfish, worms, brachiopods, sponges, trilobites
what are the benefits of binocular vision
it helps you to determine the distance between objects, and provides 3-D vision to estimate distance and depth
Who is considered the caveman
homo neanderthalensis
what is a prehensile tail
a long tail that can coil tightly around branches and objects
during what period were dinosaurs dominant
The Jurassic period
what is an index fossil
fossils found in the same layer but in many different locations that are used to compare fossil ages
what were the first life forms on primitive Earth
bacteria that were prokaryotic heterotrophs
what are the divisions of the geological time scale from largest to smallest
eon era period epoch age
what are the characteristics of primates
Long fingers and toes with nails
arms can rotate around shoulder joints
strong clavicle to stabilize shoulder
binocular vision
well developed cerebrum
why are there so few fossils of the earliest animals
they were destroyed by sediment from being too soft because the hard parts weren’t developed
where are old world monkeys found
Africa and Asia
what is biomass
The total amount of living tissue within a given trophic level
how are herbivores and carnivore similar
they are both consumers getting energy from other organisms
what is an omnivore
an organism that eats plants and meat
how are chemosynthesis and photosynthesis similar
they both involve changing energy rich compounds into simpler molecules and controlled by enzyme action
lists the levels of environmental complexity from largest to smallest
biosphere, biome, ecosystem, community, population, species, individual
why is only 10% of energy transferred from one trophic level to the next
most is expelled as heat but the first organism uses some energy
what are biotic and abiotic factors
biotic- factors of an environment that are living
abiotic- factors of an environment that are nonliving
what is a niche
full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
what is at the base of all ecological pyramids
producers
what is another name for consumer
Heterotroph
what is herbivore
interaction in which an herbivore feeds on a producer
what causes wind
differences in atmospheric pressure which is largely created by the unequal heating of earths surface
why can two organisms not have the same niche
The resulting competition for resources will result in one species being driven out or sent extinct
what is the difference between primary and secondary sucession
primary occurs in areas where life was previously not supported
secondary occurs where life is previously existed such as after a natural disaster
what is a predator
an animal that naturally preys on others
what is the difference between weather and climate
weather is the day-to-day conditions of earths atmosphere
climate is the average atmospheric conditions over long periods
what is mutualism
when both organisms benefit (plus plus relationship)
what is parasitism
a plus minus relationship where the host doesn’t die and one benefits while one is harmed
what is ecology
The study of interactions among organisms with each other and their environment
what is a tropic level
each level on a food chain
what is the difference between the food chain and a food web
The food chain shows the transfer of energy from one organism to the next
A food web shows the interaction of energy in an ecosystem
what are the three ecological pyramids
Energy- shows the amount of energy available at each trophic level decreases
biomass- shows the amount of living tissue decreases as you move up the pyramid
pyramid of numbers- The number of individuals decreases as you move up the pyramid
what factors affect climate
solar energy and greenhouse effect (sunlight is absorbed or reflected)
latitude (tropical, temperate, polar)
heat transport (unequal heat distribution)
what type of inheritance pattern does sickle cell anemia show
it is autosomal recessive passed from parent to offspring. in some cases it is not completely masked by dominant alleles
what type of trait does cladistic used to create cladograms
derived character (trait shared by related spps and ancestors)
how does carbon cycle through the environment
plants take in CO2 from the atmosphere to use in photosynthesis. Plants and animals break apart sugars and respire to return CO2 to the atmosphere
define the terms used to describe biomass
tropic level- each step in a food chain or web
what is condensation
water that collects as droplets on a cold surface when humid aid comes in contact with it
why do we need phosphorus
it strengthens bones and muscles and helps absorb vitamin B
it is used to make energy being the p in ATP and ADP
what is the role of bacteria in the nitrogen cycle
converts nitrogen into ammonia then into nitrates so producers can make proteins
what is the greenhouse effect
process in which certain gases (carbon dioxide,methane, and water vapor) trap sunlight energy in the atmosphere as heat
