extra Flashcards
what is mitosis similar to
meiosis II in every phase Prophase, metaphase, anaphase, and telophase
single stranded binding proteins
attach to each strand of unzipped DNA in order to keep them separated and prevent both strands from snapping back together.
DNA ligase
joins DNA fragments together, creating continuous phosphodiester bonds between them.
DNA helicase
enzyme that “unzips” the wound DNA double helix by breaking the hydrogen bonds between complementary nitrogenous bases. Helicase separates the strands of a DNA double helix, but it does not maintain the single-stranded state.
topoisomerase
As helicase unzips the wound DNA double helix, it creates tension ahead of the replication fork as the strands separate (referred to as supercoiling). Topoisomerase creates small nicks within the DNA double helix in order to relieve this tension.
DNA sliding clamp
Sliding clamp proteins help DNA polymerase (the enzyme that adds new nucleotides) stay attached to the template strand.
epinephrine and blood vessels
contricts some (digestive system to decrease blood flow) and dialates others (skeletal muscle which is essential during fight or flight)
nitric oxide function
Nitric oxide relaxes smooth muscles surrounding blood vessels, leading to vasodilation.
where does calcitonin come from
thyroid
exploitation competition
is when two species indirectly compete for the same limited resource. As one species or individual consumes more of the resource, less remains available for others, leading to reduced fitness for competitors.
Exploitation competition is indirect competition that occurs when a shared resource like territory, prey, or food is depleted.
resource partitioning
describes when different organisms or species live in the same habitat but can coexist by occupying different niches.
apparent competition
Apparent competition is an indirect form of competition in which the increase in the population of one species causes a decrease in the population of another species, due to a shared predator.
Example: If owls hunted both spiders and beetles and the beetle population suddenly increased, a subsequent rise in the owl population can be expected. More owls mean greater consumption of spiders, decreasing the spider population. Because the increase in beetles indirectly leads to a decrease in spiders, they are in apparent competition.
Apparent competition is indirect competition, where the growth of one species leads to a decline in another because of a shared predator.
intraspecific competition
Intraspecific competition occurs when members of the same species compete for limited resources (food, mates, etc.), which can lead to increased competition and potential conflicts among them.
Example: A gardener plants two basil plants in a small pot. During the dry summer, both plants compete for a limited water and nutrient supply, disrupting their potential growth.
is involved in modifying and packaging proteins and lipids. The ___ uses vesicles to send these products to various destinations in the cell.
golgi
induction
embryonic process in which one group of cells influences the differentiation of neighboring immature cells. Cells capable of directing the developmental fate of neighboring embryonic cells are known as organizers.
Organizers release signaling molecules that initiate gene expression patterns in the recipient cells, directing them to differentiate into specific cell types.
transduction
form of horizontal gene transfer in bacteria
transformation
Transformation occurs when a cell uptakes and incorporates extracellular DNA. Bacteria that are able to perform transformation are known as competent bacteria.
form of horizontal gene transfer in bacteria
transduction
form of horizontal gene transfer in bacteria
Transduction is a method of horizontal gene transfer in bacteria where a bacteriophage (a type of virus that infects bacteria) carries bacterial DNA from one bacterial cell to another.
conjugation
Conjugation is a method of horizontal gene transfer in bacteria where one bacterium transfers DNA directly to another through a pilus bridge.
secretin
Secretin is a hormone released by the small intestine in response to the presence of chyme. Its primary function is to stimulate the pancreas to secrete bicarbonate ions, which help neutralize acidic chyme in the duodenum.
what produces secretin
small intestine
what prompts the gallbladder to release bile
CCK
what holds the lipid membrane together
The major force driving the formation of the phospholipid bilayer is hydrophobic interactions. Once the phospholipid bilayer has formed, van der Waals forces, a type of intermolecular force, help to maintain this structure.
method of reproduction for archaea and bact
both binary fission
do bacteria and arachae have plastids (chloroplasts)
no bc they dont have membrane bound organelles
are ribosomes organelels
no
another name for indeterminate cleavage
regulative cleavage
During this stage, a cell can split off from the embryo and go on to form a separate organism. When this happens in humans, monozygotic twins are formed.
two sperm fertilizing the same egg
After a sperm has penetrated the egg, the polyspermy blocks occur to prevent a second fertilization. Two sperm cannot fertilize the same egg. Such an event would result in polyploidy and an inviable embryo.
DNA repliacation is
DNA replication is antiparallel, which means that new DNA is synthesized 5’ to 3’ in the opposite direction to the parent strand.
DNA methylation
DNA methylation adds methyl groups to DNA. This prevents transcription factors from binding, decreasing gene expression
heterochromatin
Heterochromatin is tightly packed DNA that is inaccessible to transcription factors. The formation of heterochromatin decreases gene expression.
histone deacetylation
Histone deacetylation results in more positive charge on histones. Because DNA is negatively charged, the histone-DNA interactions will increase in strength. The tighter the bond, the harder it is for transcription factors to reach the DNA. Therefore, histone deacetylation results in a decrease in gene expression.
missense mutatino
The ribosome may continue translating past the point of the former stop codon
nonsense mutation
the mutation will still result in a stop codon
histone acetylation
epigenetic modification in which acetyl groups are added to histones. The acetyl groups neutralize the positive charge of the histones, relaxing the electrostatic interactions between histones and DNA.
This relaxation forms euchromatin, a loosely packed form of chromatin that is easily accessed by transcription factors. The formation of euchromatin ultimately increases gene expression.
charge of histones and DNA
DNA negative
histones- positive
requirement of external reproduction
typically occurs in water or a moist area to facilitate the movement of sperm to the egg. This requires both the male and female to produce larger numbers of gametes.
genetic diversity in external vs internal fertilization
External fertilization results in higher genetic diversity compared to internal fertilization. In external fertilization, eggs and sperm are released into the environment and can mix with a larger pool of genetic material, whereas internal fertilization often involves mate selection and limits the gene pool to the mating pair.
DNA fingerprinting
genetic identification tool that identifies individuals via their DNA. These unique features include restriction fragment length polymorphisms (RFLPs) and short tandem repeats (STRs).
Since the length of RFLPs and the number of STRs vary significantly in the population, the DNA of an individual (e.g., a suspect in a crime) can be compared to that of a sample (e.g., DNA from blood left at a crime scene) for a positive match.
genomic library
A genomic library (DNA library) is a collection of the total genomic DNA from a single organism.
The steps involved in generating a genomic library include the following:
Restriction enzymes are used to cut the organism’s genome into many overlapping DNA fragments.
DNA ligase inserts the cloned fragments into plasmid vectors.
The plasmids are taken up by bacteria.
The bacteria are screened for the gene of interest using antibiotic resistance or color change methods.
After isolating the specific bacteria, they can be replicated through cloning, allowing for the amplification and analysis of a gene of interest.
RFLPs
involve cutting DNA with restriction enzymes at specific sequences, resulting in unique fragment patterns that differ in length.
STRs
is a group of nucleotides that repeats in a stretch of DNA.
ELISA
The enzyme-linked immunosorbent assay (ELISA) is a method used to check for the presence of a particular antigen. In this process, a sample is taken and put on a small test plate with antibodies. If any antibodies bind to the tested antigen, the plate changes color. This method is used to diagnose diseases (e.g., HIV).
SDS PAGE
SDS-PAGE is a type of gel electrophoresis that separates proteins according to size and charge.
what method does CAM use to prevent photorespiration
temporal isolation
minimizes transpiration (water loss) and decreases photorespiration in hot and dry environments, such as deserts, by temporally separating carbon dioxide uptake and the Calvin cycle. At night, when it is cooler, CAM plants open their stomata to absorb CO₂. During the day, the stomata close to prevent transpiration. The stored CO₂ is released for use in the Calvin cycle, significantly reducing exposure to oxygen and photorespiration.
used by desert plants
photorespiration
Photorespiration occurs when RuBisCo binds to oxygen instead of carbon dioxide. When this happens, RuBisCo will oxygenate RuBP, which interrupts the Calvin cycle.
C2 photosynthesis
C2 photosynthesis can occur when RuBisCo fixes oxygen instead of CO₂. This results in the production of a two-carbon molecule. This molecule is subsequently metabolized in a process that consumes energy and releases CO₂, reducing the plant’s photosynthetic efficiency.
cyclic photophosphorylation
Cyclic photophosphorylation is a light-dependent process universal to all plants, producing ATP without NADPH generation or oxygen release.
spatial isolation
Spatial isolation is how C4 plants avoid photorespiration and water loss. It works by transferring fixed carbon molecules to bundle sheath cells, which have lower concentrations of O2.
between aorta and left venricle
aortic semilunar valve
what kind of cells are mast cells
leukocytes
histamine function
Dilate nearby capillaries → blood flow increases.
Make capillary walls more permeable → fluid and immune cells leak out of blood vessels and into the site of injury.
cells that wont divide
The G0 phase is the stage where cells halt in the cell cycle if they are not ready to divide. Cells that will not divide are permanently in this phase.
CD4+ T cell functions
These cells recognize and kill infected or cancerous cells.
what stage does the cell rapidly grow
G2
role of acetylcholine
One role of the neurotransmitter acetylcholine is to transmit signals from presynaptic neurons to postsynaptic muscle cells at the neuromuscular junction.
Acetylcholine leaves the presynaptic neuron, moves across the synapse, and opens sodium (Na+) channels on the postsynaptic muscle cell. This allows sodium to flow down its concentration gradient into the cell, depolarizing the muscle cell’s membrane.
Depolarization triggers an action potential that releases calcium into the muscle cell, causing muscle contraction.
what is the square root of 0.09
0.3
what structures are due to shared ancestor but not same function- give examples
homologous structures- human arms and bat wings
what structures are due to NOT a ancestor but same function- give examples
convergent evolution
analogous structures
bats and dragonfly wings
what level of the ecological pyramid has the highest biomass
primary producers
The 10% rule states that, on average, only 10% of the energy stored as biomass is passed on from one trophic level to the next. Approximately 90% of energy is lost as metabolic heat between the levels.
when do sodium channels reset after being inactivated
during the hyperpolarization period
products of beta oxidation
acetyl coa
NADH
FADH2
where is DNA found in eukaryotes
DNA is found within the nucleus and the mitochondria (as well as within chloroplasts in plant cells). It is not free-floating in the cytosol.
weird function of cilia
function in receiving signals from neighboring cells or the environment.
where are mast cells found
in peripheral tissue
Na+/K+ ATPase
The Na+/K+ ATPase, also known as the sodium-potassium pump, uses ATP as an energy source to actively:
Pump three Na+ ions out of the cell (against the concentration gradient).
Pump two K+ ions into the cell (against the concentration gradient).
what has jointed appendages
arthropods
what has segmented bodies
annelids- segmented worms
arthopods
chordates
chordata
posses notochord during development - notochord, hollow dorsal nerve chord, pharyngeal slits, post anal tail
echinodermata
invertabrate marine animals
sand dollars
starfish
sea urchins
radial symmetry
rotifera
microscopic zooplankton- aquatic animals
distal tubule functions
The distal tubule reabsorbs Na+, Cl-, and water, while also secreting H+ and K+.
collecting duct function
The collecting duct reabsorbs water, secretes K+, and excretes urine to the bladder.
proximal tubule function
The proximal convoluted tubule is responsible for reabsorption and secretion. The proximal tubule reabsorbs salts, glucose, and amino acids. It also secretes certain substances like H+.
follicular phase
During the follicular phase, FSH stimulates the maturation of primary follicles into estrogen-secreting secondary follicles.
when do LH and FSH peak
Follicle-stimulating hormone (FSH) and LH peak during the follicular phase, not the luteal phase.
where does nitrogen fixation occur
root nodules
