A student reads in a newspaper that the soil in his area contains high levels of arsenic. Based on this information, he believes that his fellow high school classmates have this metal present in their bodies. To test his hypothesis, he conducts an investigation of the soil in his schoolyard to see if it is contaminated with arsenic. He tests seven different areas around the school and finds high levels of arsenic in each. He concludes that the students at the school must have high levels of arsenic in their systems as well. Which of these is the best evaluation of his conclusion?
A. His conclusion is valid because he tested enough areas of soil to validate his hypothesis.
B. His conclusion is flawed because he did not test the soil at the homes where the students lived.
C. His conclusion is valid because arsenic is a toxic metal and is easily absorbed by the human body.
D. His conclusion is flawed because he did not test the students to see if their bodies contained metal arsenic.

Answer:

an optical instrument used for viewing very small objects, such as mineral samples or animal or plant cells, typically magnified several hundred times.A microscope is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope.

Explanation:

The formula for the volume of a cylinder is V=Bh or V=πr2h . The radius of the cylinder is 8 cm and the height is 15 cm. Substitute 8 for r and 15 for h in the formula V=πr2h .

A possible claim based on the information provided could be:

The statement describes an experiment or observation that compared the count of normal liver cells to that of cancerous cells at different cell densities. The results showed that the count of normal liver cells remained relatively stable as the cell density increased, while the count of cancer cells increased at higher cell densities.

From this observation, the conclusion was drawn that cancer cells in the liver have lost the harmony and coherence that is typical of healthy tissue.

Therefore, this claim is based on the experiment/observation conducted and the comparison of the count of normal liver cells and cancer cells. It implies that cancer cells are behaving differently from normal cells in a way that makes them less orderly and more chaotic and thus different from healthy tissue.

Learn more about cancerous cells from

https://brainly.com/question/6321656

#SPJ1

See full question below

Count of normal liver cells vs. cancerous cells.

Normal liver cells (lower curve) have a relatively stable count

at increasing cell density, while cancer cells of the same cell

type show an increased count at higher cell densities. From

this, it was concluded that populations of cancer cells have

lost the harmony and coherence that is typical for healthy

tissue. What claim can be obtained from the above statement.

Water molecules must have moved out of the lettuce by osmosis. The addition of salt and other seasonings must have created a hypertonic ambiance for the cells of the lettuce.

Osmosis refers to the movement of solvent (mostly water) molecules through a selectively (semi) permeable membrane from a region of lower solute concentration to a region of higher solute concentration, in such a way as to equate the solute concentrations on both sides. Water usually moves osmotically from regions of lower solute concentration (high water potential) to regions of high solute concentration (low water potential).

Thus, water will move out of the cells of the lettuce to the surrounding (bottom of the bowl) due to the lower water potential of the surrounding.

To learn more about osmosis check the link below:

https://brainly.com/question/11534932

#SPJ4

Answer:

MRNA ou RNA?

Explanation:

Answer:

4/D

Explanation:

It would be Pp, genotypes like that are closed heterozygous because 1 allele (P) is dominate, while the other is recessive (p). It could also be called a hybrid.

Reactions of photosynthesis:

Energy from Sunlight is used to breakdown Water in order to release electrons in order to synthesize ATP and NADPH from ADP and NADP+ in the light-dependent reaction that occurs in the chloroplast. Electron transport chain, photosystem I, photosystem II, and ATP synthase are the processes involved in this stage.

The light-independent stage, also known as the Calvin cycle, uses ATP, NADPH, and CO2 as reactants to produce SUGAR (glucose), NADP+, and ADP as products.

Learn more on photosynthesis here: https://brainly.com/question/26568636

#SPJ1

The factors like genetic mutations, random mating, gene flow and genetic drift can increase genetic variance.

Genetic variations are the changes which occur in the genetic sequence of the DNA. These genetic variations are necessary as they allow the living beings to evolve and eventually survive. There are some factors which cause an increase in the genetic variation and they are genetic mutations, random mating, gene flow and genetic drift.

A genetic mutation is an alteration in the DNA sequence of a particular gene which causes a different product to form. This helps increase the genetic variance in organisms. Gene flow is defined as the movement of genes in and out of a particular population. In-flow of genes can help increase the genetic variation of individuals in that population. Genetic drift is the change in allelic frequency in a population by chance. Random mating is the mating of individuals that is not especially dictated by any social or genetic preference and leads to an increase in variation.

To learn more about gene flow here

https://brainly.com/question/29992261

#SPJ4

Answer:  Phtosynthesis

Explanation:

Photosynthesis

Photosynthesis removes carbon dioxide naturally — and trees are especially good at storing carbon removed from the atmosphere by photosynthesis

Answer:

The reproductive system??

Answer:

The water cycle is driven primarily by the energy from the sun. This solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and even the soil. Other water moves from plants to the atmosphere through the process of transpiration.

Explanation:

Answer:

This question lacks options, the options are:

A. The DNA sample comes from a bacterium or virus,

B. The DNA sample has been cut into fragments by restriction enzymes.

C. Only a small amount of the DNA sample is available,

D. The DNA sample includes regions that are transcribed into mRNA

The answer is C

Explanation:

Polymerase chain reaction, commonly known as PCR, is a molecular technique used to amplify a DNA sample into producing million copies of it. The PCR was invented by Kary Mullis in 1983 and since then it has been used to multiply DNA sample for use in molecular or forensic studies.

PCR starts with a very minute fragment of DNA sample. Therefore, scientists use the polymerase chain reaction (PCR) before they analyze a DNA sample under the condition that only a small amount of the DNA sample is available.

Explanation:

Behavioral adaptation is something an animal does usually in response to some sort of external stimulus in order to survive. Hibernating during winter is an example of a behavioral adaptation,this is common among bears.Another behavioral adaptation is migration by birds .

Answer:

The binomial nomenclature system combines two names into one to give all species unique scientific names.

Explanation:

Hope this helps, not 100% sure if this is what you are looking for :)

This is a system of providing a name with two components 1st = Generic name

2nd = specific epithet or species

this naming system was given by carolus Linnaeus

hope it helps

Answer:

D

Explanation:

Transcription = DNA to RNA

Translation = RNA to codons to create amino acids or proteins.

Answer:

Why do cells die? ... When cells are not needed, such as during certain stages of development. To create a structure in the body, for example, the outer layer of the skin is made of dead cells. To remove excess cells, such as white blood cells after an infection has been cleared.

Cells need to die bcuz a cell has only a limited amount of energy to do its function so it will not work aftr it has no energy. thus cells need to die.

Mollusks are classified into  various classes like Gastropod, Bivalvia, Cephalopoda, and Polyplacophora .

Gastropods have a special characteristics that includes spirally-coiled external shell while others mollusks usually have a flattened shell, and many of them doesn't  possess any shell as outer structure.

Four common characteristics that all mollusks share , are having soft bodies, a mantle, a visceral mass, and the foot. The phylum Mollusca has many distinctive features and  special characteristics, which include a mantle cavity, visceral mass, foot, and radula.  Mantle is the cavity which is used for breathing and excretion purpose , radula is longue like structure that helps in sensory and food grasping purpose.

To learn more about Mollusks , here

brainly.com/question/28737614

#SPJ4

Explanation:

Yes, they do they let consumers know about possible allergens and nutritional value.They can also assist those keeping to a diet.

Dysregulated translational factors and epigenetic regulation interact in B cells and contribute to autoimmune disease.

B cells play an important role in antigen presentation, antibody production, and secretion of pro-/anti-inflammatory cytokines in adaptive immunity. Several translation factors, including transcription factors and cytokines, are involved in regulating B cell development in concert with epigenetic regulation. Autoimmune diseases are generally characterized by autoreactive B cells and highly pathogenic autoantibodies. Successful B-cell depleting therapies in mouse models and clinical studies demonstrate the role of B cells in the pathogenesis of autoimmune diseases. Failure of B-cell tolerance at immune checkpoints results in the accumulation of autoreactive naive B (BN) cells with aberrant B-cell receptor signaling and dysregulated B-cell responses, leading to autoantibody-mediated autoimmune responses.

For more information on Autoimmune diseases , visit :

https://brainly.com/question/29739044

#SPJ4

Answer:

They mostly break down carbohydrates and fats. Once a protein source reaches your stomach, hydrochloric acid and enzymes called proteases break it down into smaller chains of amino acids

Explanation:

The selection of plants and livestock by agriculturalists is a critical component of successful farming.

It is important to choose the right plants and animals in order to maximize yields, reduce risk, and ensure sustainability. There are several criteria that agriculturalists use to make their selections.

The first selection criteria is climatic adaptability. This means ensuring that the plants and animals being chosen are suitable for the climate, soil, and other environmental conditions of the farm. It is important to choose varieties that are disease resistant, drought tolerant, and adapted to local conditions. Additionally, plants should be chosen based on their yield potential, harvest season, and marketability.

The second selection criteria is genetic variability. This means selecting plants and animals with a wide range of genetic diversity. This diversity is important for ensuring that the crops and livestock are able to adapt to changing environmental conditions. Additionally, genetic diversity helps to reduce the risk of disease and pest outbreaks.

Learn more about genetic variability at :https://brainly.com/question/13920863

#SPJ4

Answer: Carbohydrates on the cell membrane help cells function properly. Carbohydrates do this in two ways: helping cells recognize each other and providing protection for cells.

Answer:

Hey mate.....

Explanation:

This is ur answer.....

Hope it helps!

Brainliest pls....

Follow me! ;)

According to the rule of conservation of energy, energy can only be transformed from one form of energy to another and cannot be created or destroyed.

This indicates that unless energy is added from the outside, a system always has the same quantity of energy.

Energy conservation was different from mass conservation. However, special relativity demonstrates that mass and energy are connected by the formula E = mc², and science currently holds the belief that mass-energy is conserved as a whole. Theoretically, this means that every mass-containing object can transform into pure energy and vice versa. However, it is thought that this is only feasible under the most severe physical circumstances, such as those that probably occurred in the cosmos just after the Big Bang.

To know more about conservation of energy

https://brainly.com/question/29775341

#SPJ4

The parts of atoms include:

An atom is made up of a central nucleus and one or more negatively charged electrons. The nucleus is positively charged and contains one or more protons and neutrons, which are relatively heavy particles. Atoms are the fundamental constituents of matter.

Protons are made up of two up quarks and one down quark. Neutrons are made up of one up quark and two down quarks. The "strong nuclear force," one of the four fundamental forces, holds the nucleus together.

Learn more on atoms here: https://brainly.com/question/6258301

#SPJ1

Answer:

if mushrooms were producers the bear and tree population would also increase

Answer:

Mitochondrial DNA is the small circular chromosome found inside mitochondria. The mitochondria are organelles found in cells that are the sites of energy production. The mitochondria, and thus mitochondrial DNA, are passed from mother to offspring.