How can a scientific law be used to answer a specific question about an observed phenomenon?

A. A law can suggest an explanation for an observed phenomenon that will always be proven as fact
В. A law can offer an explanation for an observed phenomenon that is considered to be universally true

C.A law can only suggest an explanation for an observed phenomenon and cannot be tested through experimentation

The tuberculin skin test, or PPD test, is based on a delayed hypersensitivity and cell-mediated immune response to certain antigenic components of the Mycobacterium tuberculosis bacteria. Option 1 is correct.

A small amount of purified protein derivative (PPD) from the bacteria is injected into the skin and, if the person has been previously infected or vaccinated against tuberculosis, their immune system will recognize the PPD as foreign and initiate a localized immune response. This response causes a small bump or swelling at the injection site, which is measured after a certain amount of time. This test is used to screen for tuberculosis infection and is an important. Option 1 is correct.

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--The complete Question is , The tuberculin skin test, or ppd test, is based on which of the following?

group of answer choices

1. a delayed hypersensitivity and cell-mediated

2. immunity to certain antigenic components of the organism.

3. a subsequent mild cutaneous infection with mycobacterium

4. tuberculosisan antigen/antibody reactions occurring at the injection site. --

The smooth endoplasmic reticulum (smooth ER) got its name due to its appearance under an electron microscope.

Unlike the rough endoplasmic reticulum, which has ribosomes attached to its surface giving it a rough texture, the smooth ER has a continuous, smooth membrane without ribosomes. This membrane-bound organelle plays a crucial role in lipid synthesis, metabolism, and detoxification of drugs and toxins. It also helps regulate calcium ions in the cell and participates in the breakdown of glycogen.

This structure allows the smooth ER to perform specific functions, such as lipid and steroid synthesis, detoxification of harmful substances, and calcium ion storage. The absence of ribosomes and its associated smooth appearance led scientists to name this organelle the smooth endoplasmic reticulum.

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Answer:

chloroplasts allow plants to capture the energy of the sun in energy rich molecules.

Answer:

Explanation:

I  think it is [b] plz add me as brainlist

The best example of a mechanistic understanding of a function is skeletal muscle cells contracting when myosin heads attach to actin filaments and rotate, producing force. This is a clear cause-and-effect relationship that can be explained through the mechanical interactions of the muscle fibers. It demonstrates a deep understanding of the physiological processes involved in muscle movement. So, the correct answer is the fourth statement.

On the other hand, the other options provided involve broader and less specific explanations of the functions of certain organs or biological processes. While they do describe important functions in the body, they do not provide the same level of mechanistic understanding as the example of muscle contraction.

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Answer:

I believe the answer should be  A  * I will be shocked if I'm wrong*

Explanation:

 the rest of the answers were  about  other things and was going off-topic  cause it wasnt mentioning stomata so the only ones that were mentioning light intensity were A.

The significance of the elephant transforming woodlands into grasslands is providing a habitat and food for other species that depend on grass for their survival

An ecosystem is affected by biotic and abiotic factors.

Biotic factors are the living components ofbthe ecosystem.

The process of elephants converting woodland to grassland by elephants is an example of how a biotic factor affect an ecosystem.

Therefore, the significance of the elephant transforming woodlands into grasslands is that it helps provide a habitat and food for other species that depend on grass for their survival.

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Skew in male reproductive success can be attributed to factors such as sexual selection, male-male competition, female choice, and resource holding potential. These factors can vary among species and populations, leading to variations in the distribution of reproductive success among males.

These factors can vary among different species and populations, but here are a few common explanations:

1. Sexual Selection: Sexual selection refers to the process by which certain traits or behaviors increase an individual's chances of mating and reproducing. In many species, competition among males for access to mates can result in a skewed reproductive success. Males with specific advantageous traits, such as physical characteristics, behavioral displays, or social status, may have higher mating success and father more offspring.

2. Male-Male Competition: In species where males compete directly with each other for mates, dominant or more competitive males often gain greater access to reproductive opportunities. This can lead to a skew in reproductive success, as a small number of males may monopolize mating with multiple females, while other males have limited or no reproductive success.

3. Female Choice: In species where females have the ability to choose their mates, they may prefer certain males based on traits or behaviors that indicate genetic quality, good health, or high parental investment. If females consistently choose a subset of males, it can lead to a skewed distribution of reproductive success.

4. Resource Holding Potential: In species where access to resources, such as territories, food, or nesting sites, is crucial for successful reproduction, males with higher resource holding potential may have an advantage. These males can secure better resources, attract more mates, and have higher reproductive success.

It's important to note that the factors contributing to reproductive success can be complex and multifaceted, and they may interact with each other in various ways. The degree of skew in male reproductive success can vary greatly between species and populations, depending on the specific ecological and social dynamics at play.

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The arms are controlled by motor neurons in cervical levels of the spinal cord, whereas the legs are controlled by motor neurons in lumbar levels of the spinal cord.

What are neurons?
Neurons are the specialized cells responsible for transmitting nerve signals throughout the body. Motor neurons are a specific type of neuron responsible for controlling voluntary muscle movements. In the spinal cord, motor neurons are organized into specific regions or levels that control different parts of the body. The axon is a long, slender projection of the neuron that carries the nerve impulse away from the cell body towards other neurons or target cells.

The function of motor neurons in the cervical levels of the spinal cord is to control the arms, while motor neurons in the lumbar levels control the legs. The axons of these neurons transmit nerve signals to the muscles, allowing for movement and coordination.

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A (d) denture is a partial or full set of artificial teeth. A removable denture can be used to replace missing teeth and the tissues that support them.

Dentures come in two varieties: partial and full. When some of the natural teeth are still present, partial dentures are utilized; when all of the teeth are lost, complete dentures are used. Dentures are either a full or partial set of artificial teeth. The removable prosthesis is used to replace missing teeth and supporting tissue. It is constructed of acrylic resin or a combination of acrylic resin and metal. Dentures are made to be removed and reinserted by the wearer.

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Answer:

Pretty sure it’s A

Explanation:

The Arctic food web is a complex system that involves various organisms, from microscopic phytoplankton to large polar bears. The flow of energy in this ecosystem begins with the sun, which provides the energy for the photosynthesis of phytoplankton and other aquatic plants.

These primary producers are then consumed by zooplankton, which are in turn eaten by small fish and crustaceans.
The small fish and crustaceans are then eaten by larger fish, seals, and seabirds. At the top of the food chain, we have polar bears and other predators that feed on these animals. As these animals die and decompose, they provide nutrients for scavengers, detritivores, and decomposers, which help to recycle the energy and nutrients back into the ecosystem.
Overall, the flow of energy in the Arctic food web follows a hierarchical structure, where energy is transferred from one level to another. The energy flows from the sun to the primary producers and then to the consumers, and finally to the decomposers, which help to recycle the nutrients back into the ecosystem. The Arctic food web is a delicate balance, and any disruption in this ecosystem can have severe consequences for the entire food chain.

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Answer:

Hope this helps a bit, sorry if it doesn't. Have a good day/night! :}

Explanation:

Steroid Hormone: It is thought that, because of their lipophilic nature, free steroid hormones enter target cells primarily by passive diffusion through the cell membrane. After gaining entry to the cell, steroid hormones act as ligands for nuclear receptors and alter gene transcription

Protein Hormone: Small uncharged molecules can diffuse freely through a phospholipid bilayer. However, the bilayer is impermeable to larger polar molecules (such as glucose and amino acids) and to ions. These molecules pass across membranes via the action of specific transmembrane proteins, which act as transporters.

Water/Ion: Small polar molecules, such as water and ethanol, can also pass through membranes, but they do so more slowly. On the other hand, cell membranes restrict diffusion of highly charged molecules, such as ions, and large molecules, such as sugars and amino acids.

A substance that will easily pass through the membrane is: B. steroid hormone.

A membrane can be defined as the thin layer that separates the ineterior of a living cell from another, especially by forming its outer boundary or layers.

This ultimaetly implies that, a membrane provides protection for a living cell or an internal cell compartment from its environment.

In conclusion, a steroid hormone is a substance that will easily pass through the membrane.

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Answer:

C. Organisms are now divided into three kingdoms.

Explanation:

In the early 1860s, a German scientist named Ernst Haeckel suggested using a three kingdom system of classification. Haeckel's three kingdoms were Animalia, Plantae, and Protista.

The bacterium Listeria monocytogenes is found in soft cheeses, unpasteurized milk, meat, and seafood and can bring about fever, headache, nausea, and vomiting.

Listeria monocytogenes (L. monocytogenes) is a type of pathogenic (disease-causing) bacteria that thrives in moist environments like soil, water, decaying animals and plants, and can even grow in food storage methods like refrigeration.

Listeriosis is a serious disease brought about by the microorganism Listeria monocytogenes. After consuming contaminated food, listeriosis is typically contracted. Pregnant women, infants, older adults, and people with compromised immune systems are the primary victims of the disease.

There are a number of different ways Listeria can get into people's bodies. Consuming contaminated food, such as contaminated vegetables or raw (unpasteurized) milk, is frequently the source of cases.

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Answer:

d

Explanation:

i have a 90 and get 100s in my biology exams going to 10th grade

The activity in which different combinations of colored beads were obtained is an example of crossing over.

The correct option is B.

Chromosomal crossover, also known as crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes' non-sister chromatids, leading to recombinant chromosomes.

The genetic diversity of any offspring produced by the eventual union of two gametes during sexual reproduction is increased by gametes with new gene combinations created as a result of their crossing over.

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Answer:

Mitosis is nothing more than creating an exact replica of the organism that is a source. Meiosis on the other hand allows for variation between organisms. In meiosis, the organism mates with another of the same species. If the two organisms that are mating are different, the resulting offspring will have similar genes to both the parents, but also could result in mutations. In meiosis, it is more likely for the offspring to have mutations rather than in mitosis.

Answer:

Mary's genotype must be IAi while John's must be IBi. When the gametes met up at each conception, Joan got ii, James got IAi, and Pete got IBi.

Explanation:

Answer:

the egg will shrink and shrivel up

Explanation:

when a cell is put into a hypersonic solution, all water will leave the cell to create an equal balance of water on both sides of the cell wall.

Answer:

If the membrane were completely permeable, water molecules would move in and protein would move out until both solutions were the same concentration. Since the egg membrane is semi-permeable, water can move in but proteins cannot move out. If a naked egg is placed in the corn syrup the egg will shrink

Answer:

h

niinnuiExplanation:

Answer:

b

Explanation:

The average speed of an object is the sum of the distance traveled by the object relative to the total time taken to cover the distance. In other words,

Average speed = total distance traveled/total time taken

In this case, the total distance traveled by the runner = 26.2 miles while the total time taken = 3 hours and 15 minutes

60 minutes = 1 hour

15 minutes = 0.25 hours, hence

3 hours 15 minutes = 3.25 hours

Average speed = 26.2/3.25

                          = 8.0615 miles/hour

                            = 8.1 miles/hour

The correct option is b.

The organs in the abdominopelvic cavity are the most vulnerable in an automobile accident because this area is the largest cavity in the body and houses vital organs.

The abdominopelvic cavity contains the liver, stomach, spleen, pancreas, kidneys, and reproductive organs, as well as the bladder, large and small intestines, and rectum. During an automobile accident, the driver and passengers may experience blunt trauma from the impact, and the organs housed in the abdominopelvic cavity may be damaged. The severity of the damage can range from mild bruising to internal bleeding and organ rupture. Because these organs perform critical functions that are essential for survival, damage to them can have significant consequences, including shock, organ failure, and death. Thus, it is crucial to use proper safety measures, such as seat belts and airbags, to minimize the risk of injury during automobile accidents. In addition, early detection and proper treatment are essential to ensure the best possible outcome for those who experience injuries to the abdominopelvic cavity organs.

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The process of breathing involves the exchange of oxygen and carbon dioxide.

The process through which gases are exchanged between blood and bodily tissues is called diffusion. Blood carries respiratory gas to every cell in the body. Even the most remote areas of the body's tissue are supplied with blood flow by tiny capillaries.

The circulation receives oxygen from the lungs during gas exchange. The blood and lungs exchange carbon dioxide at the same time. This occurs in the lungs between a network of microscopic blood arteries known as capillaries and the alveoli.

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The purity of the water can be ascertained both physically and chemically.

We have to note that water have certain markers that tell us if the water can be said to be pure or not. Some of the commonest markers are the color, the turbidity and the odor of the water.

We also have some of the chemical markers that tell if the water is pure such as the pH of the water, the amount of certain  ions as well as the conductivity of the water. This is how we can be able to know if a sample of water is pure or is not.

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All the options are a reason that antibiotic resistance has been able to evolve in bacteria so quickly, option E is correct.

Bacteria can rapidly evolve antibiotic resistance in just days or weeks, thanks to several key factors. They reproduce very quickly, meaning that the number of bacteria in a population can grow exponentially in a short period. Bacterial populations can be incredibly large, creating a vast pool of genetic variation for natural selection to act on.

Bacteria can mutate specific regions of their DNA, boosting genetic variation and adaptation rates.  Finally, bacteria can transfer genetic material through conjugation, allowing beneficial mutations to spread quickly throughout the population. These factors combine to make bacteria highly adept at rapid evolution in response to environmental pressures such as antibiotic use, option E is correct.

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The complete question is:

"evolution is often thought of as taking thousands, or even millions, of years to occur. However, under certain conditions, bacterial antibiotic resistance can evolve in a few months (maybe even weeks!). Which of the following is NOT a reason that antibiotic resistance has been able to evolve in bacteria so quickly? Group of answer choices

A) Bacteria reproduce very rapidly

B) Bacteria populations number in the billions

C) Bacteria can mutate specific regions of their DNA to increase genetic variation

D) Bacteria can transfer genetic material between individuals through a process called "conjugation"

E) None of the above

Answer:

vnmvm

Explanation:

Answer:

Could you explain more?

Explanation:

Answer:

Scientists disagree on the experiments because

they all have different answers and they can't decide which one to

do so they disagree.

Explanation:

I know this because I am the goodest at science PLEASE MARK ME AS YOUR BRAINLEST!!!

Answer:

national park, an area set aside by a national government for the preservation of the natural environment. A national park may be set aside for purposes of public recreation and enjoyment or because of its historical or scientific interest.

National Park refers to an area strictly reserved and protected by the government to preserve the endangered species of plants and animals generally termed as the flora and fauna. There are around National Parks in our country of which, The National Park at Satpura is known as the first Reserve Forest of India.

Explanation: