Biology Quiz 1 Flash Cards

Why do saturated fats clog arteries while unsaturated fats do not? (Hint: think of the physical structure of these fats)

Unsaturated fats are bent due to the double bond while saturated fats are straight, allowing the saturated fats to stick to the sides of arteries and the bent unsaturated fats to just 'bounce' off the artery walls.

What is one reason why some mutations are neither good nor bad?

Up to 97% of human DNA is estimated to be in non-coding regions which do not directly code proteins. Although some mutations in this area can affect how other genes are expressed, others will have no effect.

What are some of the ways in which pathogens have adapted to counteract the effectiveness of immune system agents such as macrophages?

(1) Some pathogens are encased in a capsule made primarily of carbohydrates that disrupts the macrophage's ability to adhere to the pathogen, impairing the macrophage's ability to ingest and neutralize it. (2) Some pathogens allow themselves to be ingested into the cell, and then release proteins that cause rapid expansion and rupturing of the cell.

What are the advantages and disadvantages of the four molecular models?

-Molecular formula: Simple and easy to use, but lacks information -Structural formula: offers more information about arrangement, but lacks 3d representation -Ball-and-Stick: Complex, but offers most information possible -Space-Filling: Less information than ball-and-stick, but more realistic

Describe the five effects that combine to form a protein's 3d shape.

1) hydrophobic and hydrophillic molecules search for low energy states 2) Hydrogen bonds form between adjacent amino acids 3) Covalent bonds form (disulfide bridges) (these are the strongest) 4) Ionic bonds form between charged tails 5) Van der Walls interactions occur between atoms.

Describe three things that may happen if life were suddenly structured mainly on ionic bonds.

1. Three things that might happen: 1. Organism would dissolve among the liquids of its body. 2. All bets on energy metabolism would be off; cellular respiration and photosynthesis pathways would not be possible 3. Complex multicellular organisms would not be possible to support itself. etc. (people would possibly be made out of some form of metal)

While all cells are different in their functions, can you name a shared trait amongst the composition of all cells?

1. all contain DNA or 2. all contain a cell membrane or 3. all contain ribosomes

There are two models that can depict an atom: the ring model and the electron cloud model. List at least 1 advantage of each.

14 Hydrogens

Use the periodic table of elements to find how many valence electrons a Stromtium atom has. Is it highly reactive?

2 valence electrons. Reactivity depends on how complete the valence shell is. Since Strontium's valence electrons are minimal, it has a greater capability to become more stable by losing its electrons.

Playing as a devil's advocate, what arguments would you make against the Miller-Urey experiment

2. Arguments against Miller-Urey 1. No evidence actually demonstrates how those amino acids can become complex chains of molecules that can sustain life 2. The experiment may not fully emulate prehistoric climates.

Which type of mutation is more likely to result in a nonfunctional protein: base-pair deletion or translocation?

A base-pair deletion would be more likely to result in a non-functional protein; a single base-pair deletion will result in extensive missense in the remainder of the protein, as the three-base-pair "words" have been shifted by a single base.

Form often dictates function. How does the form of a molecule such as a lipid or protein affect its function?

A good example of form dictating function in lipids is the phospholipid bilayer that forms cell membranes. The atoms of each molecule are formed in such a way that part of the lipid (the head) is polar and hydrophilic. The other part (the tail) is nonpolar and therefore hydrophobic. This specific structure allows for the lipids to form a bilayer, with water on both the outside and inside of the cell. It also means that the cell membrane is particulalrly selective in what can pass through it. For proteins, form completely dictates function. A simple example of this is the composition of atoms around the active site of enzymes. Their particular shapes and charges allow for very specific molecules to bind to them. Because their forms can vary so much (based on the amino acids involved and the folding of the enzyme), there are specific enzymes for each different reaction to be catalyzed.

Is a high HDL (or low LDL) - linked cholesterol number a good or bad thing? Why?

A high HDL (high-density lipoprotein) or a low LDL (low-density lipoprotein) number is a good thing because it is correlated to a decreased risk for cardiovascular disease. This is because the cholesterol carried by HDL is "good" because HDL can transport it to the liver where it can be reused by the body. If the cholesterol were to remain at high quantities in the blood stream, the person would be at risk for constriction of their blood vessels.

Hypothesize about why there are fewer proofreading mechanisms for transcription than replication.

A mistake in replication leads to a mutation in DNA, and that mutation is later copied and spreads as cells divide, possibly permanently changing the body's production of a certain protein. A mistake in transcription impacts only one strand of mRNA. Lots of mRNA strands are synthesized at once, so in most cases, a mistake doesn't impact very many individual proteins. There is also lots of redundancy in codons, so a mistake at a single base could have no or little impact even on the protein synthesized from that mRNA strand.

Given that chlorine has an atomic number of 17 and aluminum has an atomic number of 13, would a molecule consisting of chlorine and aluminum be polar or nonpolar and why?

A molecule made up of Al and Cl would be polar, becuase chlorine has a much higher electronegativity than aluminum and would thus attract shared electrons more.

What is meant by the phrase "DNA replication is semiconservative"?

A new DNA molecule contains only one newly synthesized strand. The second strand is half of the original DNA molecule.

How do pH buffers affect a substance's change in pH?

A pH buffer is a solution made of weak acids and weak bases that provide resistance to pH change. For example, bicarbonates act as a natural buffer to stabilize the pH of blood.

What data would have supported the conservative hypothesis in the Meselson and Stahl experiment which involved the use of isotopes of nitrogen as biomarkers to distinguish parental and daughter DNA strands.

A supporting evidence would be 1st generation: heavy, 2nd generation: half heavy and half light

How were bioassays used to determine what the chemical substance of genetic material is?

A virulent bacteria was treated with heat to kill the bacteria. These were then treated with different enzymes that destroy proteins, DNA, or RNA specifically and then added to living non-virulent bacteria. All cultures still transformed the non-virulent to virulent bacteria, except for the culture treated with DNase which destroys DNA. Since the destruction of DNA stopped the bacteria's transformaiton, DNA is the cause of the transformation/ is the chemical substance of the genetic material.

How do ADP and ATP play a role in a cell's use of energy?

ATP is useful in storing energy because of the three phosphates bound to it. ATP breaks into an inorganic phosphate and ADP due to ATP's instability, which produces energy. They are often found in mitochondria which are known to produce energy.

Why might alternative RNA splicing mean that a drug might work in some cells but not others?

Alternative RNA splicing treats different parts of the pre-mRNA as introns and exons and cuts out different segments to create different proteins in different cells. Because of this, the proteins in one cell might be very different from those in another cell with the same DNA, causing a drug to only be effective on one of the cell types.

How can you distinguish between plant cells and animal cells besides structural differences, given a hypotonic environment?

An animal cell will lyse in a hypotonic environment, while a plant cell, due to its cell wall, will not.

The DNA replication process has many built-in safeguards such as mismatch repair and nucleotide excision repair; however mutations still occur. Comment on the evolutionary and life prospects of a species which has developed an error-free replication process.

An entity which can duplicate its DNA flawlessly will be able to produce 'perfect' organisms. This would lead to no genetic diseases or defects. However, the species would be largely unable to evolve, as no genetic mutations would exist to vary the species.

Explain why small organism such as bacteria can develop adaptations to their environment more rapidly than larger organisms such as cats.

As smaller organisms such as bacteria tend to reproduce more rapidly, evolution can occur more rapidly.

Explain why leading and lagging strands are necessary in eukariotic DNA replication.

Because DNA polymerase can only function in the 5' to 3' direction, and DNA is an anti parallel structure, the Okinawa fragments of the lagging strand are necessary. As the leading strand is constructed with the DNA polymerase, DNA primase sets the (OH-) primers in segments along the lagging strand because the lagging strand can only be constructed in reverse from the direction that the DNA is being replicated.

Explain why eukaryotic DNA replicates at thousands of sites of origin and prokaryotic DNA only has one.

Because eukaryotic DNA is linear replicate from a single site of origin would be more difficult and time-consuming than replication of round prokaryotic DNA. Only using a single point of origin is also more effective for bacteria because the replicated DNA separates in a single loop and doesn't need to be joined together like eukaryotic DNA.

Bacteria use plasmids to become resistant to antibiotics. While this is mostly harmful to humans, how might scientists use that to their advantage in the laboratory?

Because plasmids are fairly easy to extract and manipulate, scientists use them to their advantage. They can attach a gene they want to be expressed to a plasmid carrying a gene for antibiotic resistance. When they grow the cells, some will have the target gene and some won't. If they then expose the cells to the specific antibiotic, however, they kill off all of the cells that did not take up the plasmid (which carries both the target gene and the antibiotic resistance). Only cells that have the plasmid and can express the desired gene remain.

Why does the fact that prions are simply proteins make them more dangerous than most other infectious agents?

Because prions are proteins, they are not technically living meaning they can survive in a wide range of harsh environments, unlike bacteria. As long as they aren't denatured, they can survive indefinitely. Also, since there is no dna in the prion, there are limited methods of treating harmful prions in the body compared to other pathogens (no using visuses for mutation).

Hypothesize what would happen if the lipids in an average mammalian cell's phospholipid bilayer were replaced with saturated lipids.

Because the lipids are saturated, they are able to pack more tightly together than the unsaturated lipids found in most mammalian cells. Because of this, average temperatures would make the cell's membrane much more rigid from the increased Van der Waals forces.

If a double-stranded sample of DNA contains 20% cytosine, what is the percentage of adenine in the sample?

Because the percentage of cytosine in the sample is 20%, the percentage of guanine must be 20% -- they are pairs. The remaining 60% is divided evenly between adenine and thymine; as a result, the sample of DNA is 30% adenine.

Why does the FDA now require saturated fat and trans fat content levels on processed food packaging?

Both saturated fat and trans fat pose health risks to humans when eaten in quantities larger than the body needs. Because saturated fats have no double bonds between the carbon atoms in the molecular skeleton, they can pack more tightly together and provide more energy. Trans fats, which are unsaturated fats in trans- isotope form, can pack together even more loosely than saturated fat and thus carry more energy. Processed foods usually have high levels of saturated and trans fat, which increase LDL and the risk of cardiovascular diseases.

Is it harder to separate CO2 or NaCl? Why?

CO2. CO2 molecule contains covalent bonding. NaCl contains ionic bonding.Covalent bonds are stronger than ionic bonds. Stronger bonds make it harder to separate the molecule.

How do the properties of carbon lend it to being the "building block of life"?

Carbon atoms have 6 protons and 6 electrons, meaning that the L valence shell is half full making it very reactive. Carbon atoms can form both single and double covalent bonds as well, lending to a wide range of reactions necessary for life.

What about carbon's chemical structure makes it the chemical basis for all life?

Carbon has a total of four electrons in it outer shell and this means that it can bond with other atoms via single and double covalent bonds. This characteristic allows carbon to bond with a variety of other atoms to make many compounds.

Why is carbon ideally suited to be the basis for organic chemistry?

Carbon is the most plentiful element on Earth. It can also bond simultaneously to four other elements or molecules, making it well-suited to form long hydrocarbon chains, an essential component of life.

Explain the molecular properties that make phospholipids good for forming cell membranes.

Cell membranes are composed of a phospholipid bilayer. The phospholipids are composed of a glycerol bound to two fatty acids and one phosphate group. The two tails are hydrophobic and align with each other to minimize contact with polar molecules. The head is hydrophilic and faces outward in the cell membrane and interacts with water. This phosopholipid bilayer creates the cell membrane and allows for compartmentalization and dictates interaction between the cell and its outside environment.

What are cell membranes made of, and why is this molecule used?

Cell membranes are made of phospholipids (double layer) because the fatty acid tails are hydrophobic, forming the molecules into a thin sheet.

Why is it often difficult to see cellls under a microscope, and what techniques are used to improve our ability to observe their intricacies?

Cells are largely made of transparent water. A number of different techniques can be used to increase the contrast of cells under microscope, i.e. fluroscence microscopy (staining), dark-field microscopy (angling the lightsource), phase contrast microscopy (sending light through the lens, producing a perceivable phase-shift)

In general why are cells smaller than 500 microns?

Cells are usually smaller than 500 microns because they need to have the correct ratio of surface area to volume. If the cell is too large then the surface area is too small and this limits the number of substances that can be transported into and out of the cell. Cells need to maintain the proper flow of substances into and out of the cell to make sure that they can function properly.

How can we see cells? (You aren't allowed to answer "with a microscope")

Cells, while mostly water, are stained with color. Therefore, the objects in the foreground will contrast those in the back. In a more common microscope, a light microscope, light is shown through the cell and optical lenses can be adjusted to focus light and magnify the image.

Compare and contrast the positive and negative benefits that lipids can have on health.

Cholesterol is a precursor to more complex steroids and is important to biological functions in the cell membranes of animal cells. However, having too much cholesterol in the blood raises the risk of heart disease. HDL-linked cholesterol can be transported out of the blood into the liver and high levels of HDL decrease the risk of heart disease. High LDL on the other hand, raises the risk. Fats allow animals to store energy more efficiently, provide necessary fatty acids, cushion organs, and provide insulation. However, in excess, fat can have a number of negative health consequences.

How would a deletion of three base pairs in a row be potentially less detrimental than the deletion of only one or two base pairs?

Codons are three base pairs long. If a codon is deleted, the amino acid that the codon codes for will be missing from the protein when the gene is expressed. This may result in a nonfunctional protein, but it also could result in a protein that is at least partially functional. If less than three base pairs are deleted, then only part of a codon will be deleted. This results in a frame shift mutation, where most amino acids added after the deletion will not be the correct amino acid and most likely the resulting protein will be completely nonfunctional.

Is computational biology science? Argue for or against.

Computational biology is not science, but a facilitator of science. Scientific discovery requires the observation of data, and computational models can not provide data. They can, however, guide us in the right direction towards asking good questions. They can also help us develop our intuition for how things work. They are not, alone, science.

Why is control important in experiments?

Control in experiments is important so that the conclusions due to the experiment are reliable. The conclusions usually rely on correlation between indepent and dependent variables, so experimenters need to ensure that variation in the dependent variables is due to variation in the independent variable.

How are secondary structures held together?

Hydrogen bonds form between the oxygen of a carboxyl group and the hydrogen of the fourth amino group in the chain.

Name two proteins that take part in the unwinding of the DNA double helix at the start of replication and explain their functions.

DNA helicase is a protein that helps during replication by breaking the hydrogen bonds between the two strands of the DNA double helix. Another protein that takes part in the unwinding process is topoismomerase, which helps relieve the strain that is on the double helix by binding to the DNA at the point in front of the replication fork.

Some people relate telomeres to aging. What could be the correlation between these?

DNA is replicated many, many times in each human throughout a lifetime. During each replication, telomeres, the protective DNA at the end of each strand, can be shortened. Some people believe that when those strands get shorter they lose their ability to protect the DNA during replication, potentially causing cancer and other effects of aging.

How would a DNA lesion develop, and how would it be repaired?

DNA lesions are caused by environmental effects such as UV exposure, and are repaired by the process of nucleotide excision repair.

Why does replication proceed differently on the two strands of DNA?

DNA polymerase III, which does the majority of the base pairing in replication, can only add bases going from the 5' end to the 3' end. This is easy when building a strand that goes that direction. However, to build the strand that runs from 3' to 5', DNA polymerase III must add base pairs in short segments, Okazaki fragments, going from 5' to 3' which are later connected.

What is the difference between "deductive reasoning" and "inductive reasoning" in practicing science?

Deductive reasoning uses general principles to identify specificic instances whereas inductive reasoning draws general principles from specific instances

Explain why a person with type B blood cannot receive a blood donation from someone with type A blood.

Different blood types have different carbohydrate markers on their surfaces. The body of someone with type A blood will consider the markers on type B blood to be foreign and reject it.

Using the concepts of osmosis and tonicity, predict what would happen to a set of animal cells placed in a volume of distilled water.

Distilled water, which should contain no impurities, will create a hypotonic environment and a very strong concentration gradient (the ion concentration outside the cell is effectively zero). In an attempt to even the concentrations, water will flow into the cells. However, since the concentrations can never be zero both outside and inside the cells, water will continue to be drawn into the cell. This causes the cells to swell and likely burst.

How did Dr. Zheng of the Center for Neurologic Diseases at Harvard Medical School determine that mitochondrial functions were directly related to Parkinson's disease?

Dr. Zheng and his team discovered that specific genes in mitochondia were turned off in a Parkinson's patients. When these genes were turned on, proteins would be generated to regulate the electron transport chain, which produced ATP (energy that patients lacked).

How might the DNA replication process be affected if the cell containing the replicating DNA was deficient in single-strand DNA binding proteins (SSBs)?

During DNA replication, the DNA double helix is separated into two separable strands of DNA by DNA helicase. SSBs bind to the unpaired base pairs and prevent them from rejoining to each other. With reduced amounts of SSBs, the DNA strands might tend to rejoin after being separated by DNA helicase, impairing the cell's ability to successfully replicate its DNA.

Give an example of a falsifiable and testable hypothesis.

Example of Hypothesis: Every rose has the same number of petals.

What are some differences between the potassium ions moving against the concentration gradient through the sodium-potassium pump and osmosis, where water moves from lower concented solutions to higher concentrated solutions?

Energy is needed to move ions against their concentration gradients. Osmosis occurs naturally when water moves from lower to higher concentrated solutions to maintain homeostasis. Another difference is that during the first process, there can be ions moving in both directions, whereas osmosis normally has water flowing in one direction at a particular time.

Using your knowledge of how enzymes work, describe why an enzyme is most effective at a partiular temperature, and how higher or lower temperatures decrease effectiveness

Enzymes are most effective at a particular temperature, whereabove, the physical structure of the enzyme is changed and the enzyme is denatured. At lower temperatures, the reaction rate is lower due to the reduced amount of random motion, and therefore a reduced number of collisions

Why do animals store energy mainly using fats and not polysaccharides?

Fatty acids are more compact than polysaccharides and can store twice as much energy.

Describe a way that florescent labeling could be used to learn more about cells.

Florescent labeling could be used to learn what proteins are contained in the plasma membrane of cells in a specific part of the body. This could help scientists determine the function of those cells.

What is meant by the fluid mosaic model of cellular membranes? Why is it important to think of membranes in this manner?

Fluid Mosaic' refers to the liquid distribution of the surface proteins in a membrane; they can float around in the phospholipid bilayer. This means that channels and surface structures are not fixed, but rather can move to accomodate the cell's functions.

What is the main difference between phase-contrast microscopy and fluorescence microscopy? Describe a sample for each type.

Fluorescence microscopy uses stains that can be linked to specific proteins, whereas phase-contrast microscopy will allow cellular components with differing densities to have higher contrast against each other. Fluorescence microscopy could be used to detect viruses; phase-contrast could be used to view organelles in animal cells.

Fluorine is a highly reactive element. Given that fluorine has an atomic number of 9, explain fluorine's high reactivity.

Fluorine is highly reactive because it has 7 electrons in its valence shell, as indicated by its atomic number of 9. It lacks only one electron to fill its valence shell. Furthermore, it has a higher electronegativity than other elements because its nucleus is so close to its valence shell. The positiviely-charged nucleus will exert a larger pull on its electrons, and the atom will seek another electron to fill its valence shell.

Explain why free radicals might cause new chemical bonds to form, and are considered an extneral mutagen

Free radicals, a charged oxygen molecule with one fewer electron, thus they will actively steal electrons from other molecules, forming new chemical bonds, potentially causing mutations.

How are isomers and functional groups related?

Functional groups are molecules directly involved in chemical reactions. Their positioning on isomers affect the chemical properties and reactivity of the isomer.

Compare and contrast Germline and Somatic mutations.

Germline mutations occur in cells which produce gametes, and are transmitted to future offspring, Somatic mutations occur in nongamete cells and are only passed on to other somatic cells within the body

Hereditary diseases are caused by what type of mutation (germline or somatic)?

Germline mutations that have been passed down from parent to child.

How do the differing structures of the nucleotide bases lend to adenine pairing with thymine and cytosine pairing with guanine in DNA?

Guanine and adenine are both purines, meaning that they have a double ring shape. Cytosine and thymine are both pyrimidines, meaning that they have a single ring structure. Because of the differing sizes, it makes sense for one purine to be paired with one pyrimidine for uniform width in the DNA. Guanine and cytosine also want to form 3 hydrogen bonds, while adenine and thymine want to form 2.

How does the fact that there are 64 encodings for 20 amino acids mitigate genetic mutations?

Having 64 encodings for 20 base pairs allows for a lot of redundancy in DNA replication and translation. Even with the STOP encodings, most amino acids have multiple encodings. This means that if there is a mutation that changes an encoding, there is a signficant chance that the mutation will be silent mutation and will actually encode for the exact same amino acid.

Why is it necessary for cells to have a properly fluid cell membrane?

Having a cell membrane that is too rigid would inhibit passive diffusion across the membrane, endocytosis, and exocytosis, all of which are necessary for maintaining homeostasis in the cell. Also, if the cell's membrane is too fluid, the membrane would be too permeable, letting in objects that the cell should not.

Why is cell size limited by the ratio of volume to surface area?

How quickly a cell moves material in and out of the cell is dependent on the surface area, but the amount of material requiring movement is dependent on the cell volume. Because volume grows cubicly and surface area grows quadratically, cells need to have a low volume-to-surface area ratio so that materials can be transported efficiently.

Explain what happens to hydrophobic bonds when hydrophilic bonds do not exist.

Hydrophobic bonds would not be possible without the presence of hydrophilic ones. This is because hydrophilic bonds form and drives everything else that are hydrophobic to form together, acting as if there was a bond between hydrophobic molecules.

Why is it important for bacteria-infected patients to take their full antibiotic regimen?

If a patient takes some, but not all of their medication, it will only kill off the least resistant bacteria, leaving behind the more resistant ones. If the infection returns, these resistant bacteria may resist medication and present a problem.

How could a point mutation affect RNA transcription?

If a point mutation occurs in one of the sequences that initiate or terminate RNA transcripton, it could cause premature termination, or stop termnation or initiation from occurring.

Why is it important that DNA can be 'unzipped' without breaking apart into pieces?

If the DNA could not be unzipped, the replication of DNA and the passing on of genes from generation to generation would be nearly impossible or at least much more difficult. In addition, RNA could not be produced to code for proteins essential to life.

A researcher received a sample cell. How can she determine if the cell is eukaryotic or prokaryotic? If it is eukaryotic, what is a general way to differeniate a plant cell and an animal cell?

If the cell does not have a membrane-enclosed nucleus (and if it is very small), it is prokaryotic. She should be able to observer membrane-enclosed organelles in a eukaryotic cell. If the cell eukaryotic has a cell wall or a chloroplasts, then it is more likely to be a plant cell.

What makes a double helix strong in structure?

In a double helix, anything trying to pull a molecule apart would have to fight the numerous hydrogen bonds that are entangled together instead of just breaking one chain. This is not unlike how braided steel cables can support significantly more load than a single cable for the same weight.

How does the chemical nature of a cell's phospholipid bilayer determine which molecules can passively enter the cell?

In a phopholipid bilayer, the lipid molecules naturally orient themselves with their hydrophilic heads outward, and their hydrophobic tails inward (towards each other). Consequently, the interior region of the bilayer is strongly hydrophobic. Therefore, only particles that are nonpolar (unlike water, which is polar) can pass through the plasma membrane. However, exceptionally small polar molecules can pass through the bilayer simply by being small enough to fit between the lipids.

How could a scientist use their knowledge of the structure of DNA to determine whether a sample of DNA is from a bacteria or a virus?

In cells, DNA has a double helix structure, but in viruses DNA may be single stranded. Due to the way the double helix forms base pairs, the ratio of A:T and C:G should be roughly 1:1 in bacteria. In viruses with single stranded DNA the ratios will vary because the bases are not paired.

Explain the difference between conservative and semiconservative replication. Which model is used for DNA?

In conservative replication, the origional strand remains intact. In semiconservative replication, the origional strand splits in half and each half resides in one of the two copies. This is the method used for DNA.

What is wrong with saying that the results of an experiment confirm a hypothesis?

In science, nothing is ever certain. Because there is always the probability, no matter how small, that the results of an experiment were obtained by mistake, it is better to say that the results of an experiment support a hypothesis. In different scientific communities, different levels of probabilistic certainty are needed before a hypotheses can be considered appropriately supported by evidence but the results are never absolutely certain.

Do you think that germline mutations or somatic mutations would have a greater impact on the evolution of a species? Why?

In terms of animals, (where germline and somatic mutations are different), germline mutations; while somatic mutations can change the individual, germline mutations are mutations in the gametes. This means that these mutations will be passed onto the offspring, which would affect the evolution of the species more.

Given that Chlorine has an atomic number of 17 and a mass number of 35.45 amu, explain (or draw) what its ring diagram should look like.

In the center, there should be a bundle of 17 protons and 18 neutrons. Around this, there should be a total of 17 electrons from the 1st shell containing 2 electrons, the 2nd containing 8, and the 3rd containing 7.

Explain the difference between deductive and inductive reasoning.

Inductive reasoning involves making inferences, while deductive reasoning does not. This means that deductive reasoning is necessarily truth preserving (if all of the premises are true then the conclusion must also be true), but it only rearranges information scientists already know rather than leading to new information. Inductive reasoning, on the other hand, is not necessarily truth preserving but can lead scientists to new conclusions. As a result, deductive reasoning is most useful for learning about specific instances, while inductive reasoning is often used to come up with general principles.

Is deductive reasoning or inductive reasoning more useful to biologists? Why?

Inductive reasoning is more important because it allows biologists to come up with general principles that are validated by physical data.

How does new technology impact the scientific method?

New technology expands the means and capabilities of humans to observe and process data. For example, we are able to answer many questions through data crunching (e.g. genomics) rather than a traditional scientific procedure.

Which type of gene error is worse: insertions/deletions or substitutions, and why?

Insertions and deletions. These are frameshift mutations that cause the pairs following the initial mutation to also change.

Cell membranes are selectively permeable. Given the structure and composition of the phospholipid bilayer, why is it difficult for ions to pass through the cell membrane?

Ions are small particles, but they are charged. Due to the nonpolar nature of phospholipid tails, the bilayer repels ions.

Could another lipid molecule replace the phospholipids in our cell membranes?

No - The phospholipid is unique in its structure of a hydrophilic head and a hydrophobic tail, a trait unique to the phospholipid.

Why is it important that the polymerase proteins do not just leave the scene after completing replication of a DNA strand?

It is important because DNA polymerase can make mistakes and thus, by 'proof-reading' the genes, make revisions and correct the errors.

Was the change from Linnaeus' taxonomical system to the modern system good or bad? Why?

It was bad because the new system is based on evolutionary similarities while Linnaeus' was based on physical similarities, which is more intutitive to everyone except for biologists.

Analyze how does the pathogen Listeria interact with the immune system.

Listeria takes advantage of the immune system by allowing the macrophage's phagocytosis to take it in. Then it replicates itself inside the cell before the cell's toxins can kill it. It then leaves the cell and infects other cells using actin from the macrophage's cytoskeleton.

What happens when a cell quadruples in size and what has nature done to solve this issue?

Its surface area to volume ratio becomes to small, preventing the cell from absorbing enough nutrients to power the cell funcitons. In order to solve this issue a large cell may adapt to use very little nutrients or many cells may combine to perform the function of a very large cell.

Describe how a macromolecule would enter a cell.

Large molecules cannot fit in the protein channels in cell membranes and must use endocytosis to move into cells. In endocytosis, the plasma membrane of the cell folds around the molecules to move in, forming a vescicle which then detaches from the membrane on the inside of the molecule and can move within the cell to its destination.

Explain which characteristics of peas made them an effective tool for the investigation of inheritance.

Large number of seeds, grow rapidly, limited number of expressed trait

The relationship between structure and function is an important theme in biology. In this chapter, we learned about the structure of cells. Much of that information can also be applied to multicellular structures. Using that knowledge, explain the structure and shape of leaves.

Leaves have a very distinct structure. They are very thin and flimsy and tear easily, which seems like a disadvantage. This structure is so important to a tree's survival, however. Particularly in areas dense with trees, each tree has to compete for resources (sunlight, CO2) to do photosynthesis. The structure of the leaf gives is a very high surface area to volume ratio that allows for each leaf to get the maximum amount of sunlight and CO2. And each tree has hundreds of leaves to maximize its potential for survival.

What are the physical states of unsaturated and saturated fats at room temperature, respectively? What bond allows for this difference to occur?

Liquid and solid. This is because unsaturated fats have a double carbon bond between the sixth and seventh carbon atom, causing a kink to form that makes it harder for it form into a solid.

Digestion in eukaryotes takes place in special organelles called lysosomes. Explain why it is beneficial to conduct digestion in special organelles rather than in the cytosol.

Lysosomes contain special digestive enzymes, which typically work best under relatively low pH levels. The cytosol's pH is much higher, so these enzymes will not work well in the cytosol. Additionally, these digestive enzymes might target various structures in the cell if they were not contained within lysosomes.

Predict what the effects of a genetic mutation that alters the structure of collagen would be.

Many parts of the body could be affected. Skin could be unusually elastic and prone to bruising. Ligaments and tendons could be too stretchy, causing joint subluxations and dislocations. Internal organs could be affected, resulting in gastroparesis or heart valve prolapse. Affected blood vessels could be prone to rupture.

Prions are disesase-causing variants of existing proteins. As far as modern science is aware, what are the major differences between prions and their associated normally-functioning proteins?

Many prions are slightly structurally different. For example, the prion PrPSc, a variant of PrPc, has a higher beta sheet content.

What is mRNA and from where and to where does it go?

Messenger RNA brings the necessary information from the nucleus to ribosomes, which create the proteins transcribed by the mRNA.

What is the function of microvilli?

Microvilli are an adaptation used by certain cells to increase the amount of surface area relative to the volume of the cell.

What is the process of mismatch repair and what errors lead to the use of it as a process?

Mismatch repair occurs when a strand of nucleotides is formed that does not conform to base-pairing rules as a result of incorrectly replicated DNA and DNA polymerase failing to catch an error in the nucleotides. Mismatch repair is the process that occurs when en ezyme cuts out the wrong nucleotide from a daughter strand of DNA and then puts in a new nucleotide that conforms to the base-pairing rules.

What molecules can pass through a phospholipid bilayer and why is it able to pass through?

Molecules such as oxygen, carbon dioxide, and hydrocarbons can pass through because they dissolve in the hydrophobic interior of the phospholipid bilayer; they are nonpolar.

How might the structure of a monosaccharide (straight vs ring) change its ability to bond with other monosaccharides?

Monosaccharides in linear arrangements are shaped so that they could potentially form hydrogen bonds on one side. Ring arrangements, however, easily form polysaccharide chains.

What would happen to a person if he/she does not have any HDL?

Mostly likely the person will suffer from stroke and blood clots. The lack of HDL significantly lowers the ability for the body to transfer cholesterol within the body and causes buildup.

Considering mutations and natural selection, would it be true that any given population of organisms would be able to adapt to their environment as time passes? Explain.

No. It is possible that mutations will act against any given population, thus potentially leading to the complete eradication of the entire population.

Do you believe that the Miller-Urey experiment successfully proved that life developed from a process similar to that simulated in the experiment? Why or why not?

No. While I do believe the experiment successfully showed that organic compounds can be formed from inorganic ones, I do not believe that it proves that the process led to early life. Because the Miller-Urey experiment did not show how the organic compounds created could lead to more complex life-sustaining ones, it is plausible that life developed through another process not used in their experiment and provides only a small amount of incremental support for the hypothesis.

What are Okazaki fragments and why do they form?

Okazaki fragments are 1000-2000 nucleotide strings of DNA that form during the replication of DNA from the 5' to 3' end, because polymerase only moves 3' to 5'

One sample cell is observed to gain negative charge within a few seconds. What might have been transported in or out of the cell? How is the substance transported through the cell membrane?

One possibility is that protons have moved out of the cell, and the protons are transported by a proton pump, another possibility is that 3 Na+ have moved out and 2K+ moved in through the Na+/K+ pump.

What is the heaviest (most massive) essential element found in the human body?

Oxygen.

What might peer review be beneficial in ways that repetitions of the same experiment by the same researcher(s) are not?

Peer review would allow for other researchers to verify and perhaps even modify the original experiment. When modifications are made and progress is achieved, a publication is released to notify other researchers of their successes as well as mistakes.

Our ability to understand, sequence, and modify DNA is a huge milestone in science, but it makes some people uneasy. What might people be afraid of?

People are afraid of that our understanding of DNA might negatively impact the human race. People worry that we might genetically modify humans and override any natural selection; they fear that we could eliminate any genetic diversity (which has already been done with foods like bananas - there is only one type of banana left being produced); and they worry that if everyone's genome was sequenced, they would lose their privacy and their health insurance (if insurance companies can see that they have a certain disease, etc).

Researchers often use E.Coli to produce proteins that are difficult to synthesize using other methods. Given the genetic structure of bacterial cells, how might researchers use E.Coli to synthesize proteins?

Plasmids (additional circular pieces of DNA unique to prokaryotes) can be used to incorporate certain genes into E.Coli's DNA. These genes, when activated, will cause the bacterium to produce the protein, which can then be harvested by researchers.

Explain how plasmids contribute to the spread of drug resistance in bacterial communities.

Plasmids pass between bacteria easily. This means that a bacterium with a plasmid that codes for drug resistance can pass it to surrounding bacteria, spreading that trait.

Which model for displaying molecules best highlights polar covalent bonds?

Polar covalent bonds can cause molecules to bend into unique shapes. Many models of molecules do not accurately capture this bending action. A simple molecular formula contains none of this information and structural forumlas cannot capture angular bending in three dimensions. Furthermore, the space filling molecule model hides the bond lines. Therefore, the ball-and-stick formation best shows these interesting molecular arrangements that arise from polar covalent bonding.

There are many forms of polysaccharides and different forms invoke different functionalities. Summarize the main functions of polysaccharides.

Polysaccharides are mainly used for energy storage, cellular structures, and cell-cell recognition.

Oh no! There are evil eukaryotic cells migrating towards you! Luckily you notice that these cells don't have cell walls. What is one effective way of defending yourself?

Pour pure water on them and they will explode due to the hypotonic effect. Cool! Edit: Also adding a superconcentrated solution can make them shrink or lose all its water.

During DNA replication the two strands are not replicated under the same mechanism. What molecules does one strand use but the other doesn't?

Primase, RNA primer and Ligase are used in replication of the lagging strands but not in the leading strands.

Compare transcription in prokaryotes and transcription in eukaryotes.

Prokaryotes only have one type of RNA polymerase, while eukaryotes have three. Promoters in prokaryotes and eukaryotes are different. This is more diversity in eukaryote promoters. In eukaryotes, transcription factors help RNA polymerase bind to the promoter. Sigma, a protein subunit, is what helps RNA polymerase bind in prokaryotes. Unlike prokaryote RNA, eukaryote RNA has to undergo processing before it is ready to be translated.

Why do pH changes cause protein denaturation?

Protein R groups have different charges and thus act differently in acidic and basic solutions. How these R groups interact with each other and with the solution determines how a protein folds, so changing pH changes protein shape.

Explain why the order of amino acids in a protein is so vital to its function.

Protein function is determined by its structure, which is determined by the order of the amino acids which comprise it.

Describe the dissociation that occurs when salt is mixed with water.

The more electronegative oxygen atom of the water molecule tears the sodium ion away from the chlorine ion, which itself is linked to the less electronegative hydrogen of other water molecules.

Given that one of the main functions of the liver is to regulate chemical contents of the blood, can you explain why much of the glycogen in our bodies is stored there?

Since the liver processes and regulates many of the chemicals in the blood it makes sense that it would also store glycogen nearby so it can be accessed conveniently. This allows glucose to be distributed quickly through the bloodstream to places that need it.

How is new technology affecting our definition of science?

Science has traditionally been defined as hypothesis-based search for information, but the capabilities of new technology such as genome sequencing enables a greater collection of data without necessarily beginning from a scientific inquiry.

If a patient has a low "high-density lipoprotein-linked cholestoral", is she more or less likely to have cardiovascular diseases? What about low "low-density lipoprotein-linked cholestoral"?

She is more likely to have a higher risk of cardiovascular diseases if her HDL-linked cholesterol is low, and a low LDL-linked cholestoroal would be correlated to decreased risk of cardiovascular diseases.

Taking into account the connection between cytoskeleton and metastasis, devise a treatment that could prevent new tumors from forming in a cancer patient.

Since metastasis involves rapid growth of cytoskeletal features, chemicals that attack fast growing tubulin chains could slow the spread of the disease.

Why is smooth endoplasmic reticulum prominent in liver cells?

Smooth ER breaks down toxic substances like alcohol, and the liver is where alcohol breakdown occurs.

Explain the possible positive effects of spontaneous genetic mutation.

Some random mutations may enable an organism to survive more effectively in its environment. Organisms with this trait are then more successful at surviving to reproduce, thus being favored by natural selection.

Why are starch and glycogen molecules good molecules for energy storage in plants and animals and what makes them accessible for energy supply?

Starch is composed of glucose monomers which are metabolized directly and used for energy. The starch can be easily broken down into the respective monomers.

Given what you know about the bonds that form between different types of nitrogenous bases, what can you postulate about the melting temperature of the DNA of organisms with a higher concentration of guanine and cytosine bases?

Such organisms would be able to tolerate high temperatures that would otherwise disrupt the weaker bonding (2 H) formed between adenine and thymine. These organisms would usually inhabit deep sea thermal vents, and as such, have a greater melting temperature.

How did the Hershey-Chase experiment use radioactive isotopes of sulfur and phosphorus? Why weren't other elements used?

Sulfur was used to tag proteins because DNA does not contain sulfur. Phosphorus was used to tag DNA because proteins do not contain phosphorus.

Give an example of a double blind experiment.

Suppose you wanted to test a flu vaccine. Provide a doctor with a syringe with "Vaccine 1" written on it and another syringe with "Vaccine A." Before each (diseased) patient comes in, tell the doctor which vaccine to use, then leave the room. Now the patient can come in, get his or her shot, then leave. Therefore, the doctor doesn't know which one is the placebo, and neither will the patient. You as the researcher, however, will know which vaccine is the placebo and will be able to take notes on how effective the vaccine is. The key here is that you, as the person who knows which one is the placebo, are emotionless as you say which vaccine to give to the doctor so that he or she does not have any intuition as to which one is the placebo. Therefore, the patient will remain clueless and the healing process will not be jeopardized.

Outline the major processes that occur during DNA replication.

The DNA double helix unwinds and separates into two individual helices. Each helix then attracts free-floating nucleotides from its surroundings using the force of hydrogen bonding. Because each base pair can only attract a certain other base pair, given enough time, the two unzipped DNA strands will eventually both become copies of the original, barring any mutations or errata.

How can tautomers cause mutations in the genetic code?

Tautomers are different forms of the same nucleotide. This change in structure sometimes allows the bases to pair incorrectly. For example, thymine generally pairs with adenine, but it's alternate form sometimes bonds with guanine. This is incorrect and could propagate errors in the code.

What would happen if you had a defective gene for telomerase?

Telomerase extends the telomeres on the lagging strand during replication so that an RNA primer can be attached and the final Okazaki fragment can be added to the sequence. Without telomerase, the new copy on the lagging strand would not be able to be completed. Over many cycles of DNA replication, the telomeres would begin to grow shorter until the end of the DNA sequence couldn't be completed on the lagging strand.

Why was the Miller-Urey experiment important? What questions still need to be answered?

The Miller-Urey experiment, which involved simulating the conditions of early earth, proved that organic molecules can arise spontaneously from inorganic compounds. This lends experimental evidence to the concept that life arose spontaneously.

Why are loss-of-function mutations mostly recessive?

The affected gene cannot code the correct protein or enzyme; however, the homologous chromosome will compensate by continuing to make normal, functioning proteins.

Given the knowledge you know about alpha and beta glucose, why do you think glucose is rarely in its linear form in nature?

The beta form of glucose is more prevalent than the alpha form because the beta form is more stable. Likewise, the linear form of glucose is far less stable than the alpha and beta forms, particularly in aqueous solutions; therefore, less of that form exists.

Are the bonds in methane (CH4) ionic or covalent? Why?

The bonds in methane are covalent, as the atoms must share electrons to complete their valence shells. Each hydrogen must share an electron with the carbon atom, and the carbon must share all of its electrons with the four hydrogens to complete their shells.

Why are two roles for carbohydrates in plants?

The carbohydrates act as both structural (in the form of cellulose) as well as biomass.

Describe how two monosaccharides join to form a disaccharide.

The carboxyl group on one monsaccharide loses a hydrogen atom, which joins to the carboxyl group of another monosaccharide to form a water molecule and a glycosidic convalent bond.

Why do certainkinds of eukaryotic cells have cell walls, and how do they serve?

The cells of plants, algae and fungi have cell walls outside their plasma membranes. Cell walls support and protect cells and serve as structural supports for the entire organism by enabling individual cells to hold their shape.

What is the structural difference between eukaryotic and prokaryotic cells that allows higher adaptability and antibiotic resistance in prokaryotes?

The conjugation pilus allows prokaryotic cells to send DNA to one another in the form of plasmids, allowing them to send each other resistance genes to antibiotics.

Why is the ratio of surface area to volume of a cell limited?

The diffusion of essential molecules is dependent upon this ratio.

Looking at a periodic table, how could you quickly determine how reactive an element is?

The elements in the rightmost column are not reactive. Other elements will react to fill their own shells. Elements whose valence shells have a complimentary number of electrons will tend to react (for example: 1 carbon [4], 4 hydrogen [1]). The number of electrons in an element's valence shell corresponds to its location on the periodic table.

What evidence about mitochondria supports the endosymbiotic theory?

The fact that mitochondria have their own DNA and ribosomes to produce the enzymes needed to produces ATP. They also split much like mitosis to produce new mitochondria.

Explain the benefits of using the space-filling model or ball-and-stick formation over the structural formula.

The first two model the geometric arrangement and spatial distribution of the molecules, of which are hard to visualize with solely a structural formula.

Why is the Golgi Apparatus called the "shipping and receiving" center of the cell?

The function of the golgi apparatus is to modify, store and export substances. The golgi apparatus tags a small molecule to many of the substances it processes and this allows various cell machinery to recognize the function of the processed molecule.

How are extremophiles able to prevent the intense conditions in their environment from degrading their genetic material?

The genetic material in extremophiles have a higher concentration of guanine and cytosine, which form triple bonds. These bonds are stronger and take more energy to break apart. In addition, extremophiles have a saturated exterior, rather than an unsaturated one.

Fad diets are growing in popularity in the United States as obesity rates rise. What do you think would be the most effective and healthy type of diet (in biological terms)?

The healthiest type of diet is actually not what most fad diets suggest. Many of them require dieters to cut out fats and sugars. While this might reduce weight, it is not an effective diet because of the lethargy it might produce. Sugars offer quick fuel while fats are stored fuel. Depleting those supplies is not necessarily good for the body, but reducing them might be beneficial. The best type of "diet" is actually just improving one's daily diet and exercise. This means eating enough vegetables, fruits, and grains to get enough vitamins, sugars, and fibers. Eating some meat and fish (for proteins and fat) is also beneficial. Exercise is also useful as it boosts the metabolism, which means that more of the fats and sugars consumed are used rather than stored (which results in weight gain).

What is the main physical difference in terms of internal structure between prokaryotes and eukaryotes?

The main difference is the presence of membrane-enclosed organelles.

Explain why methane (CH4) can or cannot form hydrogen bonds.

The methane molecule is symmetrical, so it is nonpolar. Hydrogen bonds form when hydrogen is attracted to charged areas on other molecules, so methane on its own cannot form hydrogen bonds.

Articulate the differences between the plasma membrane and the phospholipid bilayer.

The phospholipid bilayer is a component of the plasma membrane. Other parts of the plasma membrane include proteins and carbohydrates.

How would you expect the phospholipids in the cell membranes of a creature which lives in a volcano to differ from those of a human?

The phospholipids in the cell membrane of the volcanic organism would contain higher levels of saturated fatty acids, allowing them to maintain a similar level of structure at the higher temperatures to what humans have at room temperature.

What factors heavily into different varieties of fatty acids' physical state at room temperature?

The presence of cis-double bonds in the hydrocarbon chains of unsaturated fats make it less efficient to pack. The molecule packs less efficiently and its resulting higher energy causes it to exist as a liquid at room temp (as opposed to saturated and trans fats which are solids at room temp.)

A DNA adduct is mutagen wherein DNA binds covalently to an external molecule. Explain how this might affect the DNA's ability to replicate.

The process of DNA replication is entirely reliant on the shape and intermolecular forces of the enzymes and proteins that allow replication to occur. The agents that cause DNA replication, such as DNA helicase, are tailored to a very specific shape and intermolecular force "fingerprint", so to speak. A covalently bonded chemical on the DNA double helix drastically alters the shape and intermolecular force fingerprint of the DNA, akin to throwing a wrench into a elegant system of gears. Consequently, the DNA adduct causes replication to either destroy or severaly mutate the parental DNA.

What is different in the synthesis of new DNA vs the synthesis of mRNA?

The synthesis of mRNA is a process called transcription and it uses an mRNA polymerase. Although the mRNA polymerase separates the DNA, it combines the DNA in the same protein. In DNA synthesis, multiple proteins are used to unwind, copy, rewind, and stabilize the DNA.

Oil produced from cooking a beef steak and a fish steak are collected and allowed to cool to room temperature. Describe the consistency of the two lipids collected and explain the differences in appearance, relating to their chemical structure

The saturated fat from the steak will be congealed and form a solid, while the unsaturated fat collected from the fish remains liquid. As unsaturated fats contain a double cis-bond, a kink in the triglyceride chain prevents the fat from packing tightly at room temperature. Saturated fats, on the other hand are able to pack tightly as their structures are linear

What limits the size of a cell?

The size of a cell is limited by its ratio of volume to membrane. The membrane is what allows essential molecules to be transported into and out of the cell. Because of it's larger volume, a bigger cell needs greater surface area to transport all of the substances it needs. However as the volume grows, the ratio of volume to surface area decreases until the surface area is not large enough to take care of the cell's need for transportation.

What is the function of proteins in the process of healing?

The structure of proteins allow for certain functions such as structural support and immune defense, both of which may help expidite healing.

How does tRNA interact with the A,P, and E site of a ribosome during translation?

The tRNA enters the ribosome in the A site, then moves to the P site (where the amino acid corresponding to the codon from the mRNA adds to the polypeptide chain), then leaves from the E (exit) site.

Explain the process of semi-conservative DNA replication.

The two strands of the original double-helix split, each forming its own new complementary daughter strand. This way, each new double-helix includes half of the original structure.

What are the two structures of glucose and why is one more commonly found in nature than the other?

The two structures of glucose are linear and ring. The ring structure is the most common because it is more stable.

Why don't prokaryotes need telomeres?

Their DNA is in a circular form (plasmid) so there isn't an end. Therefore, there is no need for a telomere buffer end.

WIthout telomeres, what might occur at the end of every cycle of DNA replication?

There are buffer zones at the end of our chromosomes called telomeres that act as a buffer zone to protect the important information contained in our chromosomes. They also keep the chromosome ends from joining with other random things during DNA replication. If there weren't telomeres to protect our chromosomes during replication, our DNA will end up with mutations everywhere. Cancer.

Given the opportunity how would you change the Miller-Urey Experiment? How would you address common criticisms of their procedure and conclusions?

Though the book does not explicitly state the duration of the Miller-Urey Experiment, extending the experiment could potentially yield indications of the formation of complex amino acids. However, given the monumental length of time these natural processes may have occurred over, it may not be feasible or practical to extend the experiment to the length necessary to get valid results.

Suppose you come to the lab, look under a light microscope, and see several cells that have apparently burst. What type of cells are they and how do you know? Why could they have burst?

They must have been animal cells. Plant cells are unable to burst due to their cell walls. However, when animal cells are provided with plenty of water, they burst.

Why do you think the semi-conservative model is least prone to defects when replicating DNA?

This is the most effective way of replicating DNA because every new molecule contains half of the original molecule and every element has another element it naturally (in terms of molecular attraction) pairs up with, so there is no guess work as to what needs to be created for the new other half of the molecule. If an entirely new molecule or parts of the molecule was formed, the DNA could be misread and the opposite pair could be produced instead (ie TA instead of CG), which would still be plausible chemically.

What would happen to protein synthesis without stop codons?

Transcription and translation would generate proteins much too big or long. Specific proteins could not be generated and protein synthesis would not occur. Stop codons are used to tell the ribosomes to stop amino acid generation and cut off the protein.

Compare and contrast the transcription and translation processes of DNA.

Transcription, when mRNA makes copies of DNA strands, and translation, when ribosomal RNA produce the proteins coded by the mRNA, are both necessary to create proteins for the cell. Both transcription and translation have the three steps of initiation, elongation, and termination, but transcription reads from DNA and translation reads from mRNA.

How do van der Waals interactions occur?

Van der Waals interactions occur as molecule electron clouds distort due to asymmetric and change electron distribution. These distortions result in temporary dipoles and thus interactions among molecules.

Modern biology and chemical sciences revolve around engineering new organic and inorganic substances. How can scientists and engineers use the bonding properties of atoms and molecules to design and synthesize new proteins, materials, etc.?

Very complex molecules can be synthesized in the lab. This requires precise control and knowledge of how molecules bond. A truly complete answer to this question would (and likely has) filled many (official-looking) books. However, aspects that factor heavily into these techniques include molecular (and bonding) shapes, bonding energies, and valence electrons.

Knowing how a cell replicates genetic material, how do you think viruses work?

Viruses inject genetic material, in the form of DNA or RNA double or single stranded, into the cell and forces the cell's tRNAs to produce special enzymes that encourages the production of the virus.

Which microscope, light or electron, should you use to view the cells of a sunflower and why?

You should use a light microscope because light microscopes are strong enough to let us see these cells but electron microscopes also cannot be used to look at living cells.

Using essential elements in the human body, give an example of a molecule with a nonpolar covalent bond and one with polar covalent bonds

With a nonpolar covalence bond: N2, H2, O2 and etc.; With polar covalence bonds: CO2, NH3, CH4 and etc.

Briefly describe the process of x-ray crystallography and its historical relevance to the discovery of DNA's structure.

X-ray crystallography is a process in which x-rays are shot through a small sample of a crystalline, or regularly arranged, material. The manner in which the x-rays are diffracted, with some computational analysis, reveals the structure of the sample. Rosalind Franklin conducted x-ray crystallography on DNA in the 1950s. Using the results of her experiments, Watson and Crick correctly deduced the double-helix structure of DNA.

If I wanted to create a synthetic antiport, what compenents may I need?

You may need a protein that has the ability to bond to two different substances (i.e. the ones coming and going out). For secondary active transportation, you will also need that protein to be able to receive energy and transform, much like how a gate opens and closes..

Describe why mRNA is produced.

mRNA is produced to create a copy of the DNA stored safely in the nucleus. It is used to provide a copy of DNA to ribosomes, while allowing original copies to remain safe in the nucleus.