The process of introducing positive supercoils into DNA with bacterial DNA gyrase results in an alteration of the linking number of the DNA molecule.
In this case, a 400-bp piece of circular, double-helical DNA (W 0) was treated with bacterial DNA gyrase (with ATP) to introduce four positive supercoils into the DNA.
The initial and final linking numbers are given as options (a) 40, 44, (b) 0, +4, (c) 40, 36, (d) 0,-4, or (e) None of the above.
To determine the correct answer, we need to understand the concept of linking number. Linking number is a measure of how many times the two strands of a DNA molecule are intertwined or linked with each other.
A circular DNA molecule, like the 400-bp piece in this question, has a fixed linking number (W) determined by its size and shape. When a supercoiling event occurs, the linking number changes.
In this case, we are told that four positive supercoils are introduced into the DNA. Positive supercoiling results in a decrease in linking number. The formula to calculate the change in linking number due to supercoiling is:
Change in linking number = (supercoiling density) x (number of supercoils)
The supercoiling density is the degree to which the DNA molecule is twisted per unit length. For a circular DNA molecule, it is equal to the number of supercoils divided by the number of base pairs in the DNA molecule.
Given that the initial linking number is 40, we can calculate the supercoiling density as:
Supercoiling density = (40 - 0) / 400 = 0.1
Therefore, the change in linking number due to four positive supercoils is:
Change in linking number = 0.1 x 4 = 0.4
Since positive supercoiling results in a decrease in linking number, the final linking number should be 40 - 0.4 = 39.6. However, since linking number must be an integer,
we round it off to the nearest whole number, which is 40 - 0 = 40.
Therefore, the correct answer is (a) 40, 44, which shows an increase in linking number by 4 due to an error in measurement or calculation. Option (e) None of the above can also be considered correct if it is included as an option.
To know more about DNA molecule refer here
https://brainly.com/question/12499113#
#SPJ11
How would you interpret a micrograph that shows a cuboidal cell without a nucleus?
When preparing the slide, the blade did not cut through the nucleus.
Cuboidal epithelial cells have a single, central nucleus and are cube-shaped. They are typically found in glandular tissues all throughout the body in a single layer, such as a simple epithelium, where they manufacture and secrete glandular material.To prepare a slide:
Put a drop of liquid in the middle of the slide to prepare it.Place the sample on the liquid with tweezers.Place one cover slip side against the slide at an angle such that it makes contact with the outer border of the liquid drop.Slowly lower the cover to prevent air bubbles.Utilize the paper towel to absorb any extra water.learn more about slide here: https://brainly.com/question/27127116
#SPJ4
Using whole blood as the specimen of choice in an automated analytical system Group of answer choices essentially eliminates specimen preparation time. allows the operator to use a secondary tube for analysis. keeps the specimen from undergoing degradation. allows for the avoidance of carry-over.
Using whole blood as the specimen essentially eliminates specimen preparation time.
Whole Blood
Whole blood contains both the liquid fraction and the cellular elements. The liquid fraction is the blood plasma and the cellular components are RBCs, WBCs, clotting factors, etc. The whole blood is drawn from a person and transferred to plain tubes with different color tops. The color tops indicate what the contents inside the tube are.
Whole blood is used for running various tests as it reduces the time spent preparing individual specimens. It also helps to reduce errors and limits human input to a bare minimum since the system is highly automated. Also, the whole blood sample contains all the elements of blood which allows the investigator to perform a multitude of tests least of which includes the complete blood count test.
Learn more about blood here:
https://brainly.com/question/920424
#SPJ4
The condensation of a nucleoside triphosphate with a hexose 1-phosphate to form a sugar nucleotide has a small positive free-energy change. why is this condensation metabolically irreversible?
Condensation of nucleoside triphosphate with a hexose 1 phosphate to form a sugar nucleotide has a small free energy change and this condensation is irreversible because the reaction releases PPi, which is rapidly hydrolyzed by inorganic pyrophosphatase (highly exergonic).
PPi is kept low, making first step favorable & ensures results favorable energy change (exergonic) therefore formation of sugar nucleotides drives the reaction forward / is metabolically irreversible.
Reaction is strongly exergonic, due to coupling with hydrolysis of pyrophosphate (rapid removal of product shifts equilibrium forward to make reaction favorable).
To learn more about condensation of nucleoside triphosphate ,here
brainly.com/question/14077575
#SPJ4
What are the correct molar coefficients for balancing the following chemical reaction?
(NH4)3PO4 +
HCI →
NH4Cl +
H3PO4
The correct molar coefficients will be 1, 3, 3, and 1 respectively.
Balancing chemical equationsA balanced chemical equation is an equation that obeys the law of conservation of atoms.
In other words, the number of atoms of the elements in the reactants must be equal to the number of atoms of the same elements in the products.
Hence in the reaction with the chemical equation: [tex](NH_4)_3PO_4 +HCI --- > NH_4Cl +H_3PO_4[/tex]
The number of atoms of N, H, P, O, and Cl in the reactants must be the same as in the products.
Thus, the balanced equation of the reaction, in this case, will be:
[tex](NH_4)_3PO_4 +3HCI --- > 3NH_4Cl +H_3PO_4[/tex]
Therefore, the correct molar coefficients for balancing the equation are 1, 3, 3, and 1 respectively.
More on balancing chemical equations can be found here: https://brainly.com/question/15052184
#SPJ1
Scientific name of
Raw fish?
Answer:
The scientific name is Pellona sardinão.
Explanation:
Hope this helps!
If not, I am sorry.
As a result of the Ordovician Mass Extinction, many reef building organisms went extinct, but reefs recovered in only a few hundred thousand years.
This given statement, as a result of the Ordovician Mass Extinction, that many reef-building organisms went extinct, but reefs recovered in only a few hundred thousand years is false.
What happened in the Ordovician mass extinction?
The Ordovician-Silurian extinction, which occurred 443 million years ago, resulted in the destruction of 85% of all species on Earth. The many marine species living in warm, shallow coastal waters were severely harmed, most likely as a result of global cooling and declining sea levels. There were many different types of animals affected by this extinction, including brachiopods, corals, trilobites, echinoderms, and mollusks. Species that were unique to the eastern United States were particularly vulnerable.
The Late Ordovician glacier, which quickly extended over Gondwana at the beginning of the Hirnantian and changed the Earth's temperature from a greenhouse to an icehouse, is widely blamed for this extinction pulse.
Learn more about Ordovician here:
https://brainly.com/question/1175945
#SPJ4
Zebras and other grazers band together when grazing. which type of behavior is this?
The behavior of zebras and other grazers banding together while grazing indicates their social behavior to protect themselves and their group mates from predators.
Grazing: It is a process in which herbivores roam from one place to another in search of grass, small plants, etc which are the main source of food for them. It involves forage search, selection of forage, and eating the selected forage. Different animals differ in the type and method of searching and eating forage. This different grazing behavior makes them different from one another.
Although, one common thing which is observed in these grazing animals is the practice of grazing in bands or groups. This is generally noticed in the area where they have more danger from predators so they practice this banding method as a protective measure because predators find it difficult to attack groups and they get less chance to kill a lone individual.
Learn more about Herbivores here
brainly.com/question/4001122
#SPJ4
Based on the predictions of metapopulation biology, which scenario can be expected to exhibit the largest fraction of occupied habitat patches?
Meta-population is the patchiness of population in space and its role is dynamic, population insatiability, coexistence of species , the maintenance of diversity.
Metapopulation is colonization and extinction dynamics. The variable of prime concern is the proportion.As the population largest approaches the environment carrying resources become more scare and growth rate slows.
The maxima carrying number of species in environment can support indefinitely .A group of spatially separated population of similar organism which interact at some levels.It s population in which multiple populations as butterflies and cool reef fishes.Humans are evolved from multiple interconnected spread out across Africa in large meta-population.
To learn more about Metapopulation here
https://brainly.com/question/2167013
#SPJ4
Why are urban areas more likely to flood after heavy precipitation than undeveloped areas?
Because of the lack of water absorption by structures and paved roads, runoff is substantially higher in urban areas.
What are the reasons for urban flooding?
Ineffective Sewage Systems:
Many of the sewer systems that are still in use today date from the immediate post-World War II period. The majority of these systems struggle even without the additional strain of intense rain or storms because their infrastructure is outdated and deteriorated at this time.
Insufficient Drainage:
Less green space is available in metropolitan areas due to rising urbanization and the constant construction of new buildings. Urbanization depletes the natural drainage systems that are supported by vegetation and soil.
Rapid Population Growth:
Urban population growth is accelerating, yet most cities' infrastructure cannot keep up. Populations have increased during the post-war era, outpacing the capacity of the sewage facilities put in place at that time. It stresses systems that are already vulnerable.
Learn more about urban flooding here:
https://brainly.com/question/348315
#SPJ4
The process of combining two incomplete proteins to make a compete protein is called?
Answer:
Mutual supplementation
Explanation:
Because we view the world through a subjective lens influenced by a number of variables, perception is considered:________
Because we view the world through a subjective lens influenced by a number of variables, perception is considered inaccurate.
What is perception?Perception is an outcome of a given stimuli, which is subjective because it depends on how an organism senses its surrounding environment.
Perception is also subjective because environmental inputs can influence the brain and senses in distinct modes according to how an individual relates to his/her physical world.
This phenomenon (perception) is also inaccurate because responses are different in distinct organisms for the same environmental input.
In conclusion, because we view the world through a subjective lens influenced by a number of variables, perception is considered inaccurate.
Learn more about perception stimuli here:
https://brainly.com/question/14015913
#SPJ1
the researchers chose to determine co-culture all samples in the presence of interleukin-5 a cytokine. what is the most likely reason for this decision
Interleukin-5 can both promote the growth of B cells and eosinophils which are cleared when not exposed to IL-5.
What is Interleukin-5?Interleukin-5 (IL-5) is a cytokine that induces the growth of different immune cells including B cells and eosinophils.
In consequence, in this case. it is expected to observe the outcome (immune response) of immune cells in the presence of IL-5.
In conclusion, Interleukin-5 can both promote the growth of B cells and eosinophils which are cleared when not exposed to IL-5.
Learn more about Interleukin-5 here:
https://brainly.com/question/14308447
#SPJ1
Before transplanting your organs, all doctors and medical personnel must first?
Before transplanting your organs, all doctors and medical personnel must first make all efforts to save the life.
What is organ transplantation?Organ transplantation refers to the medical procedures to extract an organ in an individual to be used in another patient, which depends on antigen compatibility.
Organ transplantation always occurs after consent of involved persons/patients without exception.
In conclusion, before transplanting your organs, all doctors and medical personnel must first make all efforts to save the life.
Learn more about organ transplantation here:
https://brainly.com/question/1313114
#SPJ1
In the α helices of transmembrane proteins, the hydrophobic side chains face which direction?
In the α helices of transmembrane proteins, the hydrophobic side chains face the outside of the membrane-spanning helix.
Transmembrane proteins are a type of integral membrane protein that spreads throughout the cell membrane. Many transmembrane proteins act as gates that allow the transport of certain substances across the membrane.
Transmembrane proteins basically act as gates or docking sites that allow or prevent substances from crossing the cell membrane.
Transmembrane proteins penetrate the entire plasma membrane. Transmembrane proteins are found in all types of biological membranes. Monotopic proteins are permanently attached to the membrane from only one side
Learn more about transmembrane proteins here:https://brainly.com/question/16083238
#SPJ4
What tissue type can be found bridging the two halves of the once severed muscle bellies?
Connective tissue is the answer.
A tissue that supports, protects and gives structure to other tissues and organs in the body. Connective tissue also stores fat, helps transport nutrients and other substances between tissues and organs, and helps repair damaged tissue.
There are four classes of connective tissue: blood, bone, cartilage, and auto connective tissue. They are further subclassed and typed: I want you to be able to identify all the different types of connective tissue and learn their position in the body.
Examples of special connective tissues are adipose tissue, cartilage, bone, blood and lymph.
Learn more about tissues here:https://brainly.com/question/25331705
#SPJ4
How do xenoturbellida relate to hemichordates and nonvertebrate chordates?
The deuterostome group's gene arrangement in the mitochondrial genome of Xenoturbella bocki is remarkably close to that of the chordates and hemichordates and hence to the ancestor deuterostome gene order. Inversion and breakpoint studies particularly point to a similarity to the hemichordates.
Previous morphological investigations imply that Xenoturbella could be classified as a bivalve mollusc, a basal bilaterian, a turbellarian flatworm, a sister group to the echinoderms(nonvertebrate), or a hemichordate. Recent genetic analyses that focus mostly on nuclear genes appear to favour the Ambulacraria (echinoderms + hemichordates). In contrast, a basal deuterostome location is supported by mitochondrial sequences.
To learn more about hemichordates click here
brainly.com/question/17438824
#SPJ4
What describes the relationship between a dominant and recessive allele?
Answer:
Dominant refers to the relationship between two versions of a gene.
Explanation:
Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.
Acute gastroenteritis that occurs after an incubation period of two to three days, persists for about a week, and commonly affects children is probably caused by_______.
Acute gastroenteritis that occurs after an incubation period of two to three days persists for about a week, and commonly affects children are probably caused by Rotavirus.
Rotavirus is an endemic that causes signs of extreme diarrhea, vomiting, fever, and dehydration. it is without problems spread amongst people. Rotavirus usually causes excessive, watery diarrhea and vomiting in toddlers and young kids. youngsters may become dehydrated and need to be hospitalized.
Rotavirus is most often spread via a fecal-oral direction. that is frequently due to the fact a child does now not wash his or her hands nicely or often enough. it is able to additionally be due to eating or consuming infected meals or water. The virus might also stay on surfaces such as doorknobs, toys, and other hard objects for a long term.
learn more about Rotavirus here
https://brainly.com/question/5624293
#SPJ1
Coral in the ocean grows by budding, where the new organism grows out of the old one by mitosis. this form of replication is an example of:____.
Coral in the ocean grows by budding, where the new organism grows out of the old one by mitosis. this form of replication is an example of asexual reproduction.
Asexual reproduction is a type of reproduction that does not involve gamete fusion or changes in the number of chromosomes. Progeny resulting from asexual reproduction from unicellular or multicellular organisms inherits the complete set of genes from a single parent.
Asexual reproduction is a type of reproduction in which a single parent gives birth to new offspring. Newly produced individuals are genetically and physically identical. That is, they are clones of their parents. Asexual reproduction is observed in both multicellular and unicellular organisms.
Learn more about asexual reproduction here:https://brainly.com/question/423209
#SPJ4
An inherited defect in the ability to produce hemoglobin, usually seen in persons of Mediterranean background is: Aplastic anemia Pernicious anemia Sickle cell anemia Thalassemia 15.
An inherited defect in the ability to produce hemoglobin, usually seen in persons of Mediterranean background is thalassemia.
What is anemia and how it causes?Anemia is a condition where there are either too few red blood cells or too little hemoglobin in them.Iron-deficiency anemia, pernicious anemia, aplastic anemia, and hemo- lytic anemia are the three types of anemia.The immune system targeting the stem cells in your bone marrow is the most frequent cause of aplastic anemia. Radiation and chemotherapy treatments are two more variables that might harm bone marrow and alter blood cell formation.Aplastic anemia that runs in the family is transmitted genetically from father to offspring. Compared to acquired aplastic anemia, it is typically diagnosed in childhood and is significantly less frequent.
Learn more about hemoglobin here:
https://brainly.com/question/14947798
#SPJ4
The receptors for balance related to the semicircular canals are known as: ________
a) macula saculi
b) macula utriculi
c) crista ampularis
d) inner hair cells
Please be rightly informed that the receptor for balance which is related to the semicircular canals are known as crista ampularis
What are receptors?Receptors can be defined as those organs cells which have the ability to respond to light, heat, or other external stimulus and transmit a signal to a sensory nerve
So thetefore, the receptor for balance which is related to the semicircular canals are known as crista ampularis
Learn more about receptors:
https://brainly.com/question/17430832
#SPJ1
A moving blood clot is called a(n)
Answer:
A blood.clot is also called a THROMBUS
In the electron transport chain, electrons are shuttled through a series of membrane proteins, which creates a gradient of:__________
Electrons are shuttled through a series of membrane proteins, which creates a gradient of: Proton across the thylacoid membrane.
The electron shipping chain is a series of electron transporters embedded in the internal mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen.
Within the electron shipping chain, electrons are handed from one molecule to any other, and electricity released in these electron transfers is used to form an electrochemical gradient. In chemiosmosis, the electricity saved within the gradient is used to make ATP.
A proton gradient is shaped via two quinol oxidations at the Qo site to form one quinol at the Qi website online in general six protons are translocated: two protons lessen quinone to quinol and 4 protons are launched from ubiquinol molecules.
Learn more electron transport chain here:-https://brainly.com/question/12838824
#SPJ1
In the electron transport chain, electrons are shuttled through a series of membrane proteins, which creates a gradient of Protons.
A Proton Gradient is needed in ETS which is the result of the transfer of the electrons flowing through the ETS complexes. ETS pumps the protons from matrix of organelle to the intermembrane space.
Following are the complex that are involved in the ETS:
Complex I - NADH DehydrogenaseComplex II - Succinate DehydrogenaseComplex III - Cytochrome bc1Complex IV - Cytochrome c oxidaseComplex V - ATP Synthetase complexThe flow of electrons through ETS Complex generates a proton gradient which is needed for the synthesis of ATP through the Complex V - ATP Synthetase complex.
ETS is called as Oxidative Phosphorylation which is the indirect production of ATP . The final acceptor of electron is Oxygen in ETS.
Learn more about Electron Transport Chain here, brainly.com/question/12838824
#SPJ1
State the shortest number of days it takes an Earth observer to see the same phase of the Moon twice.
Answer:29.5 days
Explanation:
It takes 29.5 days for observers from earth to look at the moon phase twice.
What are the phases of the moon?The fact that the moon orbits the earth every 27.3 days and the phases cycle once every 29.5 days might be perplexing. The rotation of the Earth around the Sun is to blame for this.
Our Moon completes one full orbit of the Earth in 27 days, 7 hours, and 43 minutes. The distance between our Moon and far-off "fixed" stars serves as the basis for measuring what is known as the sidereal month.
However, one cycle of phases on our Moon lasts for around 29.5 days (from the new Moon to the new Moon).
Therefore earth observer takes 29.5 days to see the same phase twice of the moon.
Learn more about the moon, here:
https://brainly.com/question/13751609
#SPJ2
If you suspect your culture of bacteria has 23 x 106 cells per mL, what would you want the final dilution to be in order to end up with 96 colonies of bacteria on a petri dish
The dilution factor in order to end up with 96 colonies of bacteria is 0.23 × [tex]10^6[/tex] .
For calculating the colony forming unit bacteria;
Colony-forming unit (CFU or cfu) is a measurement of live bacterial or fungi cells and is used to calculate the colony-forming unit of bacteria. CFU counts only viable cells as opposed to direct microscopic counts, which count all cells, both living and dead, using a hemocytometer. Colony-forming units per milliliter (CFU/mL) for liquids and colony-forming units per gram (CFU/g) for solids are used to indicate the results for convenience. The miles and Misra method can be used to compute CFU, which is helpful for assessing the microbiological load and severity of illness in blood and other samples.
∴ cfu/ml = (no. of colonies x dilution factor) / volume of culture plate
23 x [tex]10^6[/tex] cells per mL = 96 × dilution factor
Dilution factor = 23 ×[tex]10^6[/tex] / 96
Dilution factor = 0.23 × [tex]10^6[/tex]
Therefore, the dilution factor in order to end up with 96 colonies of bacteria is 0.23 × [tex]10^6[/tex] .
Learn more about bacteria here:
https://brainly.com/question/27176993
#SPJ4
How do cells become different types of tissues that work together in organ systems?.
PLSSS HELP I WILL MARK BRAINLIEST I TRULY NEED HELP IM GONNA FAIL
You are an anthropologist analyzing bone remains from the grave of an ancient female human. Within one of the bones, you find an unusually high concentration of collagen. What does this suggest about the ancient female? (2 points)
She broke a bone and then died before it was fully healed.
She broke a bone and then died a few hours later.
She broke a bone at a very young age, but it fully healed.
She broke a bone at a very young age, but it did not fully heal.
Answer: C
Explanation:
The critical element of Mendel's research focus was to use ______ strains that differed with regard to only one gene
The critical element used in Mendel's research was the Pea plant strain that differed in only one gene.
What is meant by a Strain?Within a biological species, a strain is a genetic variety, a subtype, or a culture.
The examples of pea plant strain that only differed by one gene are as follows:
Height of the pea plant ( tall or dwarf)Color of the flower ( white or purple)Types of seeds (round or wrinkled)Learn more about Mendel's experiment with the help of given link:
https://brainly.com/question/24519638
#SPJ4
The continuous, low-level extinction of species is referred to as ___ extinction.
The continuous, low-level extinction of species is referred to as mass extinction.
A widespread and quick decline in the diversity of life on Earth is known as an extinction event. A sudden shift in the diversity and abundance of multicellular creatures serves as a telltale sign of such an occurrence. It happens when the rate of diversification outpaces the rate of extinction.A mass extinction event occurs when a species disappears far more quickly than it is replaced. This is typically understood as the loss of almost 75% of all species over a "short" period of geological time, or fewer than 2.8 million years.The Cretaceous-Paleogene extinction, sometimes known as the day the dinosaurs died, is the most well-known of all the mass extinction events.
learn more about mass extinction here: https://brainly.com/question/1048615
#SPJ4
Children in northern regions experience months of inadequate sunlight exposure on the skin. to prevent possible abnormal bone development, what essential organic nutrient is necessary in the diet?
Children in northern regions experience months of inadequate sunlight exposure on the skin. to prevent possible abnormal bone development, cholecalciferol is an essential organic nutrient is necessary in the diet.
In some foods and as a dietary supplement, cholecalciferol, sometimes referred to as vitamin D3 and cholecalciferol, is a form of vitamin D that is produced by the skin when it is exposed to sunlight.People who reside in subpolar and polar regions need more vitamin D. Long winter nights cause less sun exposure, which explains why.Inuit bodies have adapted to the cold, a diet high in meat, and a low UVB environment where vitamin D production in the skin is difficult.The majority of people who live in northern latitudes require vitamin D during the winter to maintain adequate amounts of circulating 25(OH)D3 for maintaining good body function and preventing illnesses.learn more about cholecalciferol here: https://brainly.com/question/4551554
#SPJ1