Final Flashcards
how many cells are formed mitosis vs meiosis
mitosis- 2 new cells are formed
meiosis- 4 new cells are formed
what kind of cell (hap/dip) is formed mitosis vs meiosis
mitosis- diploid
meiosis- haploid
does replication of chromosomes happen in meiosis or mitosis?
both
are tetrads formed in meiosis or mitosis
meiosis
what kind of cell (funct) is formed mitosis vs meiosis
mitosis- body/somatic cells
meiosis-sex cells/gametes
are identical copies of parent cells made in meiosis or mitosis
mitosis
how many times do original cells divide meiosis vs mitosis
mitosis- once
meiosis- twice
does chromosomes moving to cell equators happen in meiosis or mitosis
both
does crossing over take place in meiosis or mitosis
meiosis
name the stages of mitosis
prophase, prometaphase, metaphase, anaphase, telophase
name the stages of meiosis
prophase I, metaphase I, anaphase I, telophase I with cyokinesis I,prophaese II, metaphase II, anaphase II, telophase II (with cytokinesis II)
duplication
when there is extra of a gene on a chromosome
deletion
when a gene on a chromosome is missing
inversion
when a gene sequence on a chromosome is flipped
translocation
when chromosomes switch parts
what kind of mutation causes a gamete to be (n+1) or (n-1)
nondisjunction
what is PCR used for
to make 100 billion identical copies of a SNA sequence within a few hours (helps diagnose diseases, identify bacteria and viruses, match criminals to crime scenes, even wjen a very small DNA sample was found at the scene
what is gel electrophoresis used for
to sort and measure DNA strands, especially good to match up individuals at crime scenes, for paternal tests, etc. (DNA is negatively charged so it moves toward the positively charged end of the gel, with shortest strands moving the farthest)
describe the goal of gene therapy
to put a corrected copy of a gene in a person (usually delivered through a vector) to replace a flawed one, in other words, to fix genetic problems at their source
end product of artificial embryo twinning
identical twins. the two babies are clones of each other
end product of somatic cell nuclear transfer
in somatic cell nuclear transfer, the baby that is born is a clone of a living person (the somatic cell donor)
what are vortexes used for
to mix samples in the lab
what are centrifuges used for
to “spin down” samples and separate out contents (most dense on bottom, least dense on top)
DNA structure
made up of nucleotide building blocks which are composed of a sugar, a nitrogenous base, and a phosphate group. the shape of DNA is a double helix.
gene
basic unit of heredity. genes are on chromosomes
shape DNA vs RNA
DNA- double helix
RNA- single stranded
sugar DNA vs RNA
DNA- deoxyribose
RNA- ribose
base pair rules DNA vs RNA
DNA- A&T, C&G
RNA- A&U, C&G
key function of DNA
holds all genetic material, or code (“secret of”) of lifel the code is universal
key function of RNA
tRNa, rRNA, mRNA, help with making proteins
the steps of transcription
- ) RNA polymerase binds to a promoter; DNA unwinds [initiation]
- ) one side of DNA is used as a template & RNA polymerase adds free nucleotides (using complementary base rules for RNA) [elongation]
- ) RNA polymerase reads terminator; new RNA is released [termination]
the steps of translation
- ) codon on mRNA molecule attaches to a ribosome
- ) tRNA molecules carrying specific amino acids, approach the ribosome
- ) tRNA anticodon attaches to mRNA codon
- ) ribosome slides to the next codon on the mRNA molecule and repeats the process
- ) as amino acids are added to each other, peptide bonds link the amino acids together
- ) chain of amino acids continues to grow until ribosome reaches a stop codon on the mRNA strand. this signals tat no more amino acids should be added and protein is complete
P and A sites on ribosomes
P site (left) holds the growing chain of amino acids, A site (right) is where next amino acid is brought in
what is the difference between a codon and an anticodon
both consist of a set of three bases (“triplets”) but a codon is on mRNa and an anticodon is on tRNA (the anticodons correlate with the codons so each tRNA will bring in the correct amino acid)
name the main evidences for evolution
molecular biology, comparative embryology, fossils, biogeography, comparative anatomy
molecular biology
evidence for evolution. comparing DNA, RNA, amino acids in proteins in different organisms (more similarities means probably more closely related)
comparative embryology
evidence fr evolution. seeing how organisms develop and comparing these early life stages to help determine relatedness
fossils
evidence for evolution. use superposition, relative age and absolute age to determine historical fossil sequence in strata. good for hard parts of animals, rich in minerals, though soft parts and soft organisms rarely fossilize.
biogeography
evidence for evolution. studying distribution of animals around the world, ex: finding closely related organisms adapted to different environments in nearby regions, seemingly unrelated organisms may have similar adaptations to similar environments in regions that are far apart (think pangea for this one)
comparative anatomy
evidence for evolution. study homologous, analogous, and vestigial structures and transitional species to determine ancestry and relatedness
name the process of descent with modification using the points of natural selection
1.) overproduction 2.) genetic variation 3.) struggle to survive 4.) differential reproduction
overproduction
more offspring are produced than can survive in the environment (ex: more baby lions are always born than would ever survive past age one)
genetic variation
individuals have different traits because they receive different alleles from their parents, some traits are better than others and provide a favorable adaptation, while others don’t receive beneficial traits
struggle to survive
organisms compete for the limited resources; those who outcompete others generally are those with the best adaptations while the others die out
differential reproduction
those with the more successful adaptations survive longer and reproduce more. over time, the favorable traits become the most frequent alleles in the population, as the other alleles die out (assuming natural selection is still working, by chance, in favor of these same “favorable traits”)
homologous structure
is derived from a common ancestor, is structurally similar/same to common ancestor, but is used in different way (different function) ex: forelimbs of humans, bats, cats, and whales
analogous structure
is not derived from a common ancestor, is not structurally similar, but are used in the same/similar way (same function) ex: wings of birds, bees, bats
vestigial structure
is derived from a common ancestor, is structurally similar/same to common ancestor, but is not useful to the current organism ex: small hind leg and foot bones in whales
hierarchy of life from most broad to most specific
life, domain, kingdom, phylum, class, order, family, genus, species
what does it mean to be fit in the theory of evolution
ability to survive long enough to produce fertile offspring (your offspring must also be able to have viable offspring of their own)
define and describe genetic drift
genetic drift is a change in the gene pool of a population due to chance and it’s especially impactful in smaller populations such as populations that have undergone a bottleneck effect or a founder effect
bottleneck effect
an event such as an earthquake or flood that drastically reduces population size
founder effect
colonization of a new location by a small number of individuals
stabilizing selection
average form of a trait is slected for (and it’s the most common) while either extremes are selected against
the graph is low on either side and goes high in the middle
disruptive selection
both of the extreme forms of the trait are selected for, while the average is selected against double humps (hump, then dip down, then hump)
directional selection
one of the extreme forms of a trait is selected for while the other extreme form and the average is selected against.
the graph just looks like the regular bell curve has been shifted to one side
allopatric speciation
a speciation event that results after a geographic isolation (ex: canyon, river, etc. forms separating the population into different species over thousands perhaps the two populations can no longer interbreed- 2 different species)
sympatric speciation
a speciation event that results after reproductive isolation (ex: maybe they live in the sam area but have different niches & only breed with those of the same niches over time they maybe can’t breed together any more
define and describe adaptive radiation
the evolution of many new species from a common ancestor introduced to a new and diverse environment
example of adaptive radiation
14 finch species in the galapagos islands likely evolved from a single small population of ancestral birds that colonized one of the islands
commensalism
one organism benefits, the other neither is helped nor harmed
mutualism
both organisms mutually benefit
parasitism
one organism benefits (the parasite) while the other is harmed (the host)
list the ecological hierarchy from biggest to smallest
biosphere, ecosystem, community, population, organism
biosphere
the thin layer of Earth where life exists
ecosystem
biotic (living) and abiotic (nonliving) components in an area and their interactions
community
only the living organisms in an area
population
all members of a single species living at the same place and time
organism
a single individual member of the species
density-dependent limiting factors
affect the population dependent on how dense the population is. ex: dense populations can much more easily transfer communicable disease through the population faster, predators do better when more prey is available but once they strain the prey population and thin out their density the prey goes down in number, also causing the predator to do poorly.. as predators do poorly then prey starts doing better, but then in return predators start doing better, etc. (their success directly depends on the other organisms’ success
density-independent limiting factors
impact dense and not very dense populations the same proportionally. for instance, hurricanes, tornadoes, floods, or maybe even global warming.
how overpopulation affects world
global warming:more people= more burning of fossil fuels = more greenhouse gases.
global: also affects health and sanitation worldwide with more waste produced and greater food supply needed
how deforestation affects world
global warming: less forests = less vegetation to remove CO2 from air = higher quantities of greenhouse gases
global: hurts land fertility, causes erosion, affects oxygen levels