mutations may have an effect on the expression of an operon such as the lac operon. would the following mutations have a cis- or trans-effect on the expression of the structural genes in the operon? a) a mutation in the operator site that prevents the lac repressor from binding to it b) a mutation in the laci gene that prevents the lac repressor from binding to dna c) a mutation in lac promoter that prevents rna polymerase from binding to it d) a mutation that deletes the shine-dalgarno sequence of trp operon leader peptide.

Proteins within cell membranes control cell volume and nerve impulses by transporting sodium and potassium. These proteins, called ion channels and transporters, help maintain proper concentrations of these ions on either side of the cell membrane.

This process is crucial for cellular function and nerve impulses, as it establishes the resting membrane potential and allows for action potentials to occur.

The sodium-potassium pump, for example, actively transports three sodium ions out of the cell and two potassium ions into the cell, creating an electrochemical gradient. This gradient is essential for nerve impulse transmission and overall cell function.

In summary, proteins in the cell membrane regulate cell volume and nerve impulses by transporting sodium and potassium ions, maintaining the electrochemical gradient required for proper cellular function.

To know more about cell membrane refer here:

https://brainly.com/question/13524386#

#SPJ11

The procedure you are referring to is called neurosurgery or neuroablative surgery. It involves the destruction of a specific nerve cluster in the brain that causes or transmits uncontrollable seizures.

This procedure is often considered a last resort option for patients who have not responded to other treatments, such as medication or dietary changes. Neurosurgery can be done through different methods, such as laser surgery or radiofrequency ablation. However, it is important to note that this procedure carries risks and potential complications, including infection, bleeding, and damage to healthy brain tissue. As with any medical procedure, the benefits and risks should be carefully weighed before deciding to proceed with neuroablative surgery.

To know more about surgery visit:

https://brainly.com/question/30426456

#SPJ11

Answer:

body.

Explanation:

Normally, a zygote implants into the body of the uterus.

Reuptake inhibitors block the removal of neurotransmitters from the synaptic cleft, prolonging their availability and enhancing their effects on postsynaptic neurons.

If the neurotransmitter is excitatory for the postsynaptic neuron, the inhibition of reuptake would lead to an increased concentration of neurotransmitter in the synaptic cleft, resulting in increased frequency of postsynaptic action potentials. This increased frequency of action potentials would cause temporal summation, in which multiple EPSPs (excitatory postsynaptic potentials) are generated in quick succession, leading to an increased depolarization of the postsynaptic neuron and a greater likelihood of generating an action potential.

Thus, reuptake inhibitors increase the excitatory effects of neurotransmitters, potentially improving symptoms associated with disorders such as depression and ADHD.

Learn more about neurotransmitters

https://brainly.com/question/9725469

#SPJ4

Acclimation pens were used for wolves during the reintroduction process because it allowed the wolves to become accustomed to their new environment and prey before being released into the wild. The pens were designed to mimic the wolves' natural habitat and provide them with a safe space to adjust to their surroundings.

You asked about the use of acclimation pens during the wolf reintroduction process and the precautions taken by the wolf project staff to prevent habituation.

Acclimation pens were used during the reintroduction process of wolves to help the animals gradually adjust to their new environment. This allowed the wolves to become familiar with their surroundings, reducing stress and increasing their chances of survival when released into the wild.

To ensure the wolves did not become habituated to humans, the wolf project staff took several precautions, including:

1. Minimizing human contact: Staff limited their interactions with the wolves to essential tasks, such as providing food and medical care, to prevent the animals from becoming accustomed to humans.
2. Using camouflage: When staff needed to interact with the wolves, they wore camouflage clothing to reduce the chance of the wolves associating humans with positive experiences.
3. Feeding with natural prey: The wolves were fed with natural prey items, such as ungulates, to encourage natural hunting behaviors and prevent the wolves from relying on humans for food.
4. Monitoring behavior: Staff carefully monitored the wolves' behavior to detect any signs of habituation and take appropriate action if needed.
5. Providing a spacious and natural environment: The acclimation pens were designed to mimic the wolves' natural habitat, allowing them to practice their natural behaviors before being released.

By using acclimation pens and taking these precautions, the wolf project staff aimed to ensure a successful reintroduction of wolves to the wild while minimizing the risk of the animals becoming habituated to humans.

To know more about Acclimation visit:

https://brainly.com/question/28257643

#SPJ11

During spermatogenesis, the first cell to become haploid is the secondary spermatocyte.

Here's a step-by-step explanation of spermatogenesis:

1. Spermatogenesis begins with a diploid spermatogonium, which is the stem cell that will divide and differentiate into sperm cells.
2. The spermatogonium undergoes mitosis to produce two diploid primary spermatocytes.
3. Each primary spermatocyte undergoes meiosis I, a type of cell division that reduces the chromosome number by half, to produce two haploid secondary spermatocytes.
4. Each secondary spermatocyte then undergoes meiosis II, another cell division, to produce two haploid spermatids.
5. The spermatids undergo a process called spermiogenesis, where they differentiate into mature sperm cells.

So, in summary, the secondary spermatocyte is the first cell to become haploid during spermatogenesis.

To know more about spermatocyte visit:

https://brainly.com/question/13047015

#SPJ11

The production of less fit hybrids usually results in the process of reproductive isolation.

Reproductive isolation occurs when two different species are unable to produce viable or fertile offspring due to various barriers. When less fit hybrids are produced, it means that the offspring resulting from the mating of two different species are not well-adapted to their environment or have reduced fertility.

Over time, this can lead to the process of reproductive isolation, as the species evolve separately and develop mechanisms to prevent the production of less fit hybrids. These mechanisms can include prezygotic barriers, such as differences in mating behavior, and postzygotic barriers, such as reduced hybrid viability or fertility.

In summary, when less fit hybrids are produced, it can result in reproductive isolation as the species involved evolve separately to prevent the formation of such hybrids, maintaining the distinctiveness of each species.

To know more about reproductive, visit;

https://brainly.com/question/815744

#SPJ11

In a subduction zone, the landform that occurs when oceanic plates collide is typically a volcanic arc.

A subduction zone is an area where two tectonic plates meet, with one plate being forced under the other due to differences in density. In this scenario, the denser oceanic plate is forced beneath the less dense continental plate.

As the oceanic plate descends into the Earth's mantle, it is subjected to increased pressure and temperature, causing it to partially melt. This process creates magma, which is less dense than the surrounding rock and rises through the mantle and crust. As the magma reaches the surface, it forms a chain of volcanoes parallel to the subduction zone known as a volcanic arc.

This volcanic activity creates a variety of landforms, such as stratovolcanoes, calderas, and volcanic islands. These features contribute to the formation of mountain ranges and can cause devastating eruptions, which in turn can impact the local climate and ecosystems.

Thus, the collision of oceanic plates in a subduction zone leads to the formation of a volcanic arc, a landform characterized by volcanic activity and associated geological features.

Learn more about  subduction zone here:

https://brainly.com/question/13788626

#SPJ11

The structure indicated in the photo of a cross section through the middle of an earthworm's body is the c. ventral nerve cord.

The ventral nerve cord is the prominent structure indicated by the arrow in the photo of a cross section through the middle of an earthworm's body. It is located on the ventral (belly) side of the worm, running longitudinally from the head to the tail. The ventral nerve cord is a major component of the earthworm's nervous system, and is responsible for transmitting information from sensory neurons to the brain and from the brain to the muscles that control movement.

It consists of paired ganglia, or clusters of nerve cell bodies, that are connected by longitudinal nerve fibers. The ventral nerve cord is an essential component of the earthworm's ability to sense and respond to its environment, and to coordinate its movements in response to those stimuli.

Therefore, the correct option is c. ventral nerve cord.

To learn more about ventral nerve cord here

https://brainly.com/question/894102

#SPJ1

The mineral that can cause icterus and hemoglobinuria (red urine) in sheep is copper. In this scenario, it is likely that the sheep are experiencing copper toxicity, which can lead to symptoms such as depression, weakness, icterus, and dark red urine due to hemoglobinuria.

Copper can accumulate in the liver and cause liver damage, resulting in the release of excess copper into the bloodstream. This excess copper can then cause hemolysis, or the breakdown of red blood cells, leading to the release of hemoglobin into the urine, which causes the dark color. Copper toxicity can also cause icterus, or yellowing of the skin and mucous membranes, due to the accumulation of bilirubin, a waste product of hemoglobin breakdown. Treatment for copper toxicity typically involves removing the source of excess copper and providing supportive care to the affected sheep. In severe cases, blood transfusions may be necessary to replace the damaged red blood cells. I hope this answers your question. If you have any more questions, feel free to ask.

The mineral that can cause icterus and hemoglobinuria (red urine) in sheep is copper. In this scenario, it is likely that the sheep are experiencing copper toxicity, which can lead to symptoms such as depression, weakness, icterus, and dark red urine due to hemoglobinuria.

To know more about hemoglobinuria visit:-

https://brainly.com/question/30261523

#SPJ11

Add a mild detergent to separate an integral membrane protein from the lipid component of a cell membrane.

C is the correct answer.

Detergents (also known as surfactants) or organic solvents are typically needed to extract the protein from the bilayer in order to isolate integral membrane proteins, which calls for more extreme conditions.

The most widely used technique for isolating membrane proteins is detergent extraction combined with ultracentrifugation; however, this technique involves several steps, including mechanically disrupting cells, extensive centrifugation, and solubilizing the proteins in detergent.

Learn more about integral membrane protein:

https://brainly.com/question/10725471

#SPJ4

The complete question is:

which of the following treatments would be most useful in separating an integral protein from the lipid component of a cell membrane while retaining the proteins activity?

A. drastically change the pH

B. Add a mild detergent

C. Add a salt at a high concentration

D. Add a mixture of proteases

E. None of these. You can't separate an integral protein from the lipid without losing activity

During the Cambrian period, organisms such as archaeocyathids and stromatolites formed reefs. In the Ordovician period, the main reef-building organisms were brachiopods, bryozoans, and corals.

Archaeocyathids were sponge-like animals with hard, calcareous skeletons, allowing them to form structures similar to coral reefs. Stromatolites were microbial mats that trapped sediment and minerals, creating layers that eventually formed reef-like structures.

Brachiopods were shelled organisms that attached themselves to the seafloor and form colonies that could reach impressive sizes. Bryozoans were also colonial organisms that formed branching structures, similar to coral. Corals, well-known for their reef-building abilities, also appeared during the Ordovician period.

While different organisms formed reefs during the Cambrian and Ordovician periods, they all played a crucial role in shaping the ocean environment and creating habitats for other marine organisms. Today, the fossilized remains of these ancient reefs provide valuable insights into the evolution of life on our planet.

To know more about archaeocyathids, visit:

https://brainly.com/question/14883621

#SPJ11

Cessation of respiration refers to the complete stoppage of breathing.  The cessation of respiration would be expected following damage to the Option D) medulla oblongata.

The respiratory centers are located in the brainstem and are responsible for controlling the rate and depth of breathing.

Among the options provided, the medulla oblongata is the most likely site of damage to cause cessation of respiration. This is because the medulla oblongata contains the primary respiratory center, which controls the rhythm of breathing. It is also responsible for coordinating the actions of the diaphragm and other respiratory muscles. Therefore, damage to the medulla oblongata would lead to a complete cessation of breathing.

On the other hand, the superior colliculi and the caudate nucleus are involved in visual and motor processing, respectively, and are not directly related to respiratory regulation. The cerebellum is involved in motor coordination, but it does not have a direct role in respiratory regulation. The reticular formation is involved in regulating arousal and attention and is indirectly involved in respiratory regulation.

In summary, the cessation of respiration would be expected following damage to the medulla oblongata, which is the primary respiratory center in the brainstem.

To know more about Cessation click here:

https://brainly.com/question/1211894

#SPJ11

The substance that makes up coral reefs is calcium carbonate. This substance is deposited by organisms such as corals, as well as other calcifying organisms like mollusks and foraminifera. Calcium carbonate is a mineral that is composed of the elements calcium, carbon, and oxygen.

It is formed by the reaction between calcium ions and carbonate ions, which are present in seawater. When corals and other calcifying organisms extract these ions from seawater and combine them to form calcium carbonate, they create the hard structures that make up coral reefs. These structures provide important habitats for a variety of marine species and are also important for protecting coastlines from storm surges and erosion.

The substance that makes up coral reefs, deposited by organisms such as corals, is called calcium carbonate. Corals build their hard exoskeleton by extracting calcium ions and carbonate ions from seawater, which then combine to form this compound. As corals grow and die over time, the accumulated calcium carbonate structures create the basis of coral reefs.

To know more about foraminifera, visit:

https://brainly.com/question/31212133

#SPJ11

The spike protein in Human Immunodeficiency Virus (HIV) binds to the host cell protein CD4 and a co-receptor, either CCR5 or CXCR4, on the surface of T helper cells.

The binding of the spike protein to these receptors is essential for the entry of HIV into the T helper cells, which then leads to the replication of the virus and eventual destruction of the host's immune system. The CD4 protein is primarily expressed on the surface of T helper cells, while the CCR5 and CXCR4 co-receptors are expressed on various immune cells, including T helper cells. HIV has a high affinity for CD4 and one of these co-receptors, which allows the virus to enter and infect the host cells.

The binding of the spike protein to these receptors triggers a conformational change in the viral envelope, allowing the fusion of the viral and host cell membranes and subsequent entry of the virus into the host cell. Understanding the mechanism of HIV entry and the interaction of the spike protein with CD4 and co-receptors is crucial for the development of antiretroviral therapies that can prevent or inhibit HIV infection.

To know more about Human Immunodeficiency Virus,

https://brainly.com/question/15319125

#SPJ11

In a typical animal cell, the component that contains the greatest amount of water is the cytoplasm. This is the gel-like substance that fills the cell and is made up of water, proteins, salts, and other molecules.

The cytoplasm is important for many cellular processes, including metabolism, movement, and communication between different parts of the cell. Its high water content helps to maintain the shape and structure of the cell, and allows for the transport of molecules in and out of the cell. In summary, the cytoplasm is the component of an animal cell that contains the greatest amount of water.

The cytoplasm is a jelly-like substance that fills the cell and provides a medium for cellular processes to occur. It consists mostly of water, along with dissolved salts, enzymes, and other molecules.

To know more about cytoplasm, visit:

https://brainly.com/question/15417320

#SPJ11

the overall probability of having a child with hemophilia in this case is 25%.

If a woman whose father has hemophilia and whose mother does not, marries a man that does not have hemophilia, the probability that they will have a child with hemophilia depends on the genotypes of the parents.

The woman's father with hemophilia must have been hemizygous for the hemophilia gene, meaning that he only had one X chromosome and that it carried the hemophilia gene. The woman inherited one X chromosome from her father (with the hemophilia gene) and one X chromosome from her mother (without the hemophilia gene). Therefore, the woman is a carrier of the hemophilia gene.

If the man does not have hemophilia, then he must have two normal X chromosomes. Therefore, his genotype is XN XN.

The possible genotypes of their offspring are: XN XN, XN Xh, Xh XN, and Xh Xh, where XN represents a normal X chromosome and Xh represents a hemophilia X chromosome.

To determine the probability of having a child with hemophilia, we need to consider the possible outcomes of the cross.

The probability of having a child with hemophilia is 0% for XN XN x Xh Xh, as all offspring would be female carriers of hemophilia but would not have hemophilia themselves.

The probability of having a child with hemophilia is 50% for XN XN x Xh XN or XN Xh x XN XN, as half of the male offspring will inherit the Xh chromosome from the carrier mother and develop hemophilia.

The probability of having a child with hemophilia is 25% for XN Xh x Xh XN or Xh XN x XN Xh, as there is a 50% chance that the male offspring will inherit the Xh chromosome from the carrier mother and a 50% chance that the female offspring will inherit the Xh chromosome from the father.

Therefore, the overall probability of having a child with hemophilia in this case is 25%.

To learn more about chromosome visit:

brainly.com/question/30077641

#SPJ11

The neurons in the cortex responsible for initiating leg movement at a straight angle and a 45-degree angle would be different.

The motor cortex in the brain is responsible for initiating and controlling voluntary movements of the body. Different movements of the same body part, such as kicking the leg straight ahead versus at a 45-degree angle, require the activation of different groups of neurons in the motor cortex.

Neurons in the motor cortex are organized in a somatotopic manner, meaning that different regions of the cortex are responsible for different body parts and movements. Within each region, there are further subdivisions that control specific movements.

Therefore, the neurons responsible for initiating leg movement at a straight angle and a 45-degree angle would be different because they are located in different regions or subdivisions of the motor cortex. This specificity of motor control allows for precise and coordinated movements of the body.

Learn more about cortex here:

https://brainly.com/question/12993641

#SPJ11

The first commercial airline flight flew over Tampa Bay, a large body of water in Florida.

The inaugural commercial airline flight took place on January 1, 1914, and flew over Tampa Bay in Florida. This historic event marked the beginning of the commercial aviation industry. The aircraft used was a Benoist XIV airboat, piloted by Tony Jannus. The flight carried a single passenger, the former mayor of St. Petersburg, Abram C. Pheil, who had won an auction for the privilege to be the first passenger. The journey began in St. Petersburg and ended in Tampa, covering a distance of approximately 23 miles in just 23 minutes. This breakthrough in transportation revolutionized travel and led to the growth and development of the modern-day aviation industry we know today.

To know more about the flight visit:

https://brainly.com/question/18453350

#SPJ11

Organisms obtain the energy they need to live in their environment through a process known as energy transfer in food webs. In any ecosystem, there are producers, consumers, and decomposers.

Producers, such as plants and algae, obtain their energy from the sun through photosynthesis, converting solar energy into organic matter.

Consumers are organisms that cannot produce their own food, so they feed on other organisms to obtain energy. Herbivores feed directly on plants, while carnivores feed on other animals.

Omnivores eat both plants and animals. At the top of the food chain, apex predators consume other carnivores, and their population is limited by the availability of prey.

Decomposers, such as bacteria and fungi, break down dead organisms and organic matter into simpler compounds, which can then be recycled back into the ecosystem.

The flow of energy through the food web is unidirectional, with energy decreasing at each trophic level due to inefficiencies in energy transfer. As such, the amount of energy available to organisms decreases as you move up the food chain.

To know more about ecosystem, refer here:

https://brainly.com/question/13979184#

#SPJ11

Lights and a siren would be the most appropriate mode of the carrier for a 29-year-old woman who presented with severe chest pain that started while she was exercising. The correct answer is (A).

The symptoms of the patient might point to a cardiac event, like a heart attack, that needs to be treated right away. Utilizing lights and alarms during transport can assist with facilitating the patient's appearance at the emergency clinic and guarantee brief clinical intercession.

However, it is essential to keep in mind that the selection of lights and sirens ought to always be based on a thorough evaluation of the patient's condition as well as the potential advantages and penalties of each mode of transportation. The patient's and the public's safety should always come first.

To learn more about chest pain here

https://brainly.com/question/30506215

#SPJ4

The circadian rhythm is an internal 24-hour "clock" that regulates the sleep-wake cycle, and it is built into the human body to seek rest and maintain optimal functioning. Given statement is true

The circadian rhythm is an internal biological clock that is built into the human body and helps regulate the sleep-wake cycle. It is based on the natural 24-hour cycle of light and darkness and helps the body prepare for sleep at night and wakefulness during the day. Disruptions to the circadian rhythm can lead to sleep disorders, fatigue, and other health problems.

Learn more about “circadian rhythm“ visit here;

https://brainly.com/question/857658

#SPJ4

The relationship between cellulose-digesting microorganisms and their hosts is an example of mutualism. Here option B is the correct answer.

Mutualism is a type of symbiotic relationship where both parties involved benefit from the interaction. In this case, the microorganisms have a home and a source of food in the gut of their host, while the host gains more nutritional value from their meals.

Termites and ruminant mammals, such as cows and sheep, have a digestive system that is capable of breaking down cellulose, a complex carbohydrate found in plant cell walls. However, they lack the necessary enzymes to do so. The cellulose-digesting microorganisms living in their guts provide these enzymes, allowing the hosts to extract more nutrients from the cellulose-rich plant material they consume.

This mutualistic relationship is an important example of how different organisms can evolve to rely on each other for survival. Without the microorganisms, the hosts would not be able to extract as much nutrition from their food, and the microorganisms would not have a source of food or habitat to live in.

To learn more about mutualism

https://brainly.com/question/9557750

#SPJ4

Complete question:

Which of the following describes the relationship between cellulose-digesting microorganisms and their hosts?

a) Parasitism

b) Mutualism

c) Herbivory

d) Commensalism

e) Predation

The correct statement regarding genotype-environment correlations is: active genotype-environment correlations occur when the biological parents provide a rearing environment for the child.

Passive genotype-environment correlations occur when the child's genes are associated with the rearing environment provided by the biological parents, but this association is not due to the child actively seeking out or selecting that environment. For example, a musically gifted child may have inherited genes for musical ability from their biological parents, who are also musicians and provide a musical environment in the home.

Active genotype-environment correlations, on the other hand, occur when the child's genes influence the rearing environment that they actively seek out or create. For example, a child with a genetic predisposition for high levels of physical activity may be more likely to participate in sports and seek out active hobbies, creating an environment that reinforces their genetic predisposition.

To know more about genotype-environment,

https://brainly.com/question/20730322

#SPJ11

if a patient with Addison's disease is given too high a replacement dose of glucocorticoids, the effect over time will be an increase in muscle weakness due to the negative impact on muscle tissue caused by chronic exposure to excess glucocorticoids.

Addison's disease is a disorder in which the adrenal glands do not produce enough cortisol and sometimes aldosterone. Glucocorticoids, such as cortisol, have a variety of important functions in the body, including the regulation of glucose metabolism, immune function, and the response to stress.

Patients with Addison's disease are typically treated with glucocorticoid replacement therapy to provide the missing cortisol. However, if the dose is too high, it can lead to a condition known as Cushing's syndrome, which is characterized by a variety of symptoms, including muscle weakness, fatigue, and weight gain, among others.

Learn more about “ Addison's disease  “ visit here;

https://brainly.com/question/31595031

#SPJ4

Photosystem I (PSI) and Photosystem II (PSII) are two essential components of the light-dependent reactions of photosynthesis in plants.

PSII functions to absorb photons of light and transfer the energy to chlorophyll molecules. The excited electrons from PSII pass through a chain of electron carriers, which drives the production of ATP through chemiosmosis. The electrons lost by PSII are replaced by the splitting of water molecules, releasing oxygen as a byproduct.

In PSI, the excited electrons from PSII are further energized and used to reduce NADP+ to NADPH, which is used in the Calvin cycle to produce glucose.

Overall, PSII and PSI work together to produce ATP and NADPH, which provide energy and reducing power to fuel the synthesis of organic molecules in plants.

Learn more about chlorophyll molecules

https://brainly.com/question/27974923?

#SPJ4

Hemipteran insects, also known as true bugs, whose food sources already contain dissolved small molecules. This insects feed on

plant sap or animal blood,

Animal blood contain a variety of organic compounds such as amino acids, sugars, and vitamins that are necessary for their growth and development.

Unlike other insects that have to synthesize these molecules themselves, hemipterans can directly absorb them from their food source.

This unique feeding strategy has allowed hemipterans to evolve specialized mouthparts that can pierce through plant or animal tissues and suck up the liquid inside.

As a result, hemipterans have diversified into over 50,000 species with various ecological roles, from crop pests to predators of other insects.

To know more about plant sap refer here :-

https://brainly.com/question/488600#

#SPJ11

Waste from agricultural runoff is an example of nonpoint source pollution. This occurs when rainwater or irrigation water flows over land, picking up pollutants like pesticides, fertilizers, and animal waste, which then get carried into rivers, lakes, and other bodies of water.

Nonpoint source pollution refers to pollution that originates from a diffuse or scattered source, rather than a single, identifiable point. This type of pollution can come from various sources, such as agricultural runoff, urban stormwater runoff, or construction sites. In contrast, point source pollution comes from specific, easily identifiable sources like factories or sewage treatment plants.
In the context of your question, waste from agricultural runoff is an example of nonpoint source pollution. This occurs when rainwater or irrigation water flows over land, picking up pollutants like pesticides, fertilizers, and animal waste, which then get carried into rivers, lakes, and other bodies of water. This form of pollution can be challenging to control and manage due to its widespread and diffuse nature. Efforts to reduce nonpoint source pollution often involve promoting best management practices in agriculture, urban planning, and construction to minimize the release of pollutants into the environment.

To know more about pollutants visit :

https://brainly.com/question/1943157

#SPJ11

Answer: B

Explanation:

That delivery truck driver charges a fixed base price of $6 for 2 miles.

After 2 miles, he charges an additional $2 for every mile and after 6 miles, he charges an additional $4 for every mile.

We need to describe the cost of the delivery truck between 1 mile and 2 miles.

In the given graph x-axis represents the distance in miles and y-axis represents the cost in dollars.

From the given graph it is clear that the value of function is constant between x=1 and x=2.

It means the cost of the delivery truck between 1 mile and 2 miles is constant.

Therefore, the correct option is B.