Biology 311C Unit 2 Squarecap

Bacteria develop resistance against antibiotics by _________________________.

1. Block the entry 2. Degrade the antibiotic 3. Mutation of target enzyme

Which organisms will have linear chromosomes with histone proteins bound to their DNA? A) Bacteria only B) Archaea only C) Eukarya only D) A and B are possible E) None of these

C) Eukarya only

If the dimension of a cube shape cell is 10 µm, the ratio of cell surface area to volume would be _____ to 1.

0.6 (SA = 6X^2 = 6(10)^2 = 600; V = X^3 = (10)^3 = 1000; therefore ratio of SA:V, where V is equal to 1, is 0.6 to 1)

Three essential requirements for an ancestral cell to grow and multiply are 1. ____________________to define the cell and contain reactions within 2. ___________________ make and break molecules and 3. ___________________ material to replicate & reproduce.

1. cell membrane; 2. metabolism; 3. genetic material

A paleontologist estimates that when a particular rock formed, it contained 12 mg of the radioactive isotope potassium-40, which has a half-life of 1.26 billion years. The rock now contains 3 mg of the isotope. About how old is the rock? Enter in billions of years.

2.52

How many different types of ribosomes are found in a plant cell? Hint: consider the various locations of the plant genome.

3 - cytoplasm, chloroplast, and mitochondria

If the dimension of a cube shape cell is 1 µm, the ratio of cell surface area to volume would be _____ to 1.

6 (surface area = 6x^2; volume = x^3; therefore, SA = 6 and V = 1 and the ratio of SA:V is 6:1)

How many cellular structures is the rough endoplasmic reticulum associated with?

8 - nucleus, rough ER, cytoplasm, transport vesicles, golgi apparatus, smooth ER, plasma membrane, and other smaller cells

Both mitochondria and chloroplast are maternally inherited. Some plants develop resistance to atrazine herbicide through a mutation of a gene located in the chloroplast. If male plants without any such herbicide resistance are crossed with an atrazine resistant female plant, what will be the resistance level of offspring plants? A) All offspring will be resistant. B) None of them will be resistant. C) Half will be resistant and half susceptible. D) Only the female plants will be resistant and not the male plants. E) Only the male plants will be resistant and not the female.

A) All offspring will be resistant (Since mitochondria and chloroplasts are only inherited from the mother, all offspring will have the genes located on those organelles.)

You have isolated some organisms that are unicellular with cell wall containing peptidoglycan and have flagella without any membrane enclosure. Which group do these organisms belong to? A) Bacteria only B) Archaea only C) Eukarya only D) A and B are possible E) None of these

A) Bacteria Only

Which of the following is the most rapidly reproducing organisms, based on their simplicity or complexity? A) Bacteria only B) Archaea only C) Eukarya only D) A and B are possible E) None of these

A) Bacteria only (Bacteria being small and without any nucleus or other membrane bound organelles will replicate the most rapidly.)

Which of the following molecules do not have any charges on them so that they cannot be separated by gel electrophoresis? There may be more than one answer. A) Carbohydrates B) Triglycerides C) Proteins D) DNA E) RNA

A) Carbohydrates; B) Triglycerides (Carbohydrates have polar functional groups -OH or -C=O but not charges.)

Which of the following will affect the fluidity of a cell membrane? A) Sterols B) oligosaccharides C) saturation levels of fatty acid side chains D) peripheral proteins E) phosphate head groups

A) Sterols; C) Saturation levels of fatty acid side chains (if there are double bonds present) (Saturation levels of fatty acids will affect the fluidity)

You would be wasting your time if you were trying to use a light microscope to see_______ A) viruses B) animal cells C) bacteria D) yeast cells E) chloroplasts

A) Viruses

Phosphorylation of a series of proteins ("phosphorylation cascade") during signal transduction _____. A) causes target proteins to change their shape and therefore their activity. B) brings a conformational change to the cell's DNA. C) cannot occur in yeasts because they lack protein phosphates. D) always results in enzyme inactivation inside the target cell. E) causes binding of a hormone to a cytosol receptor.

A) causes target proteins to change their shape and therefore their activity. (Binding of phosphates causes conformational change in proteins which changes their function.)

Which of the following affects all others in the cell communication process? A) Signal reception B) Change of receptor shape C) Signal transduction D) Transcription and translation E) Physical and physiological response

A) signal reception (This is the first step in the cell communication process)

Which of the following molecules will rapidly diffuse through lipid part of cell membrane? A) Water B) Glucose C) CO2 D) Salt E) small protein

A) water; C) CO2

Which of the following animal cells produce antibodies? A) A cells B) B cells C) T cells D) Stem cells E) Liver cells

B) B cells (B cells gain memory of a particular antigen and develop antibodies)

Which of the following actions represents direct contact mechanism of cell signaling? A) Movement of chromosomes during cell division B) Transport of vesicles along microtubules C) Closing of leaves in a "touch me not" plant D) Insulin secreted by pancreas traveling to other parts of a body E) Gap junctions allowing small signal molecules to go through

C) Closing of leaves in a "touch me not" plant; E) Gap junctions allowing small signal molecules to go through (Small molecules passing through gap junctions by direct contact with cells nearby.)

How do bacteria protect themselves from a viral infection? A) By having a strong cell wall, it blocks the entry of virus B) Bacterial cell capsule protects it from viral infection C) Plasma membrane will block the virus from entering the cell D) Restriction enzymes degrade the viral DNA once it enters the bacterial cell E) Using a viral protein that competes with any new viral infection.

B) Bacterial cell capsule protects it from viral infection; D) Restriction enzymes degrade the viral DNA once it enters the bacterial cell (Restriction and methylation enzymes modify their own DNA to mark them and then degrade any foreign DNA if that enters)

Which of the following molecules will be able to cross a synthetic dialysis membrane with a pore size of 100 daltons (AMU) and not through biological membrane by simple diffusion? A) CO2 B) NaCl C) Starch D) DNA E) O2

B) NaCl

Which of the following cells can perform phagocytosis? Choose all that apply. A) Bacteria B) White blood cells C) Plant cells D) Fungal cells E) Skin cells F) Amoeba

B) White blood cells; F) Amoeba

When the pH was increased from 5 to 7 in an in vitro experiment, these structures purified from animal cells stopped digesting their contents. What are these structures? A) smooth ER B) lysosomes C) nucleus D) mitochondria E) Golgi vesicles

B) lysosomes (lysosomes contain hydrolytic enzymes that digest macromolecules (need acidic environment). These enzymes are active at pH 5, but are inactive if the pH is raised to 7.)

What is the effective method of preventing or fighting Corona Virus-COVID 19 infection proposed in this article? Last month, Hangzhou-based Ascletis Pharma applied to the Chinese authorities to test two HIV protease inhibitors (ritonavir and ASC09) in clinical trials to treat COVID-19, the illness caused by the new coronavirus (Table 1). And Suzhou-based BrightGene Bio-Medical Technology announced in early February that it would begin to manufacture Gilead Sciences' Remdesivir (GS-5734), a broad-spectrum investigational antiviral, as a treatment for coronavirus infection. Remdesivir originally developed to treat Ebola virus and then dropped, will also be tested by Gilead in partnership with Chinese health authorities in randomized, controlled trials. "The general genomic layout and the general replication kinetics and the biology of the MERS, SARS and [SARS-CoV-2] viruses are very similar, so testing drugs which target relatively generic parts of these coronaviruses is a logical step," says Vincent Munster, chief, Viral Ecology Unit, US National Institute of Health. Testing therapies approved for other indications also makes senses, as these drugs are already mass-produced and available on a large scale.

By Gilead Sciences' Remdesivir (GS-5734) which will block the replication

Vaccines protect the animals by ___________________________ A) Preventing viruses infecting the body B) Preparing enzymes to degrade the virus C) Helping to produce antibodies that will mark virus for degradation D) Mutating the human skin cells to resist viral infection E) Activate the killer T cells to kill the infections.

C) Helping to produce antibodies that will mark virus for degradation (Vaccines are proteins of viruses or weakened viruses that is recognized by the antibody producing cells. The antibodies made then recognize the real virus and mark them for degradation by macrophages or killer T cells.)

Which of the following action facilitated by microfilaments will a plant cell not be able to do? A) Movement of chromosomes during cell division B) Transport of vesicles along microtubules C) Cleavage furrow (pinching in middle of cell) formation during cell division D) Cytoplasmic streaming of chloroplasts E) Synthesis of carbohydrates and essential amino acids

C) Cleavage furrow (pinching in middle of cell) formation during cell division (The tough cell wall will prevent the cell from pinching in the middle or cleave)

Most of the antibiotics are derived from ______________________ A) Algae B) Bacteria C) Fungi D) Plants E) Animals

C) Fungi (Penicillin, ampicillin and streptomycin all are derived from fungi.)

What structures are similar to each other in the list given below? A) Tight junctions and primary cell wall B) Secondary cell wall and anchoring junctions C) Plasmadesmata and gap junctions D) Middle lamella and anchoring junctions E) Gap junctions and secondary cell wall

C) Plasmodesmata and gap junctions (Both connect adjacent cells through small pores through the plasma membrane or cell wall)

Refer to the ECG chart segment shown above and choose the point which represents the depolarized state that results in the action potential. A) P B) Q C) R D) S E) T

C) R (R represents the most positive membrane potential and leads to the action of reversal to make the membrane potential negative.)

If you were to genetically engineer a papaya plant that will resist fungal disease, you would like to express high levels of the enzyme _____________ that will degrade the fungal cell wall. A) proteinase B) phosphatase C) chitinase D) cellulase

C) chitinase (Fungal cell walls are made out of chitin, so chitinase will degrade chitin and, therefore, the cell wall)

What type of receptors would bind to the lipid soluble hormones? A) G-protein linked receptors B) Tyrosine kinase receptors C) Cytosolic receptors D) Both A and B E) All A, B and C

C) cytosolic receptors (Steroid hormones being non-polar can easily diffuse through cell membrane and are recognized by soluble protein receptors in cytoplasm.)

Which of the following structures are important for providing energy for cytoplasmic functions in a plant? A) microtubules B) chloroplast C) mitochondrion D) lysosome E) nucleus

C) mitochondrion (Mitochondrion makes ATP for the cellular functions)

Which of the following is the correct sequence of plant cell structural layers, beginning with the cytoplasmic side and progressing outward? It may help to draw two adjacent plant cells and the cell walls to answer this question. A) Plasma membrane, middle lamella, secondary wall, primary wall B) Middle lamella, primary wall, secondary wall, plasma membrane, C) Plasma membrane, secondary wall, primary wall, middle lamella D) Primary wall, middle lamella, secondary wall, plasma membrane, E) Plasma membrane, secondary wall, middle lamella, primary wall

C) plasma membrane, secondary wall, primary wall, middle lamella (The innermost structure is the plasma or cell membrane. Then it is the secondary cell wall, then the primary cell wall which is the toughest and most exterior portion of the cell. The middle lamella is jelly-like and connects two adjacent cells together.)

Which of the following molecules are the most essential for cell communication? A) DNA B) RNA C) Proteins D) Lipids E) Polysaccharides

C) proteins (Proteins are the receptors and effectors in cell communication due to the variety of the structures and the functions they are capable of.)

A sewage line broke and contaminated drinking water source of a rural town. You are asked to investigate if there is any bacterial contamination after fixing the sewage leak. What methods would you follow?

Cell fractionation, use of a light microscope

Arrange the following processes in the order in which they evolved from oldest to latest. 1. Photosynthesis 2. Respiration 3. Neuron signaling A) 1, 2, 3 B) 1, 3, 2 C) 3, 2, 1 D) 2, 1, 3 E) 2, 3, 1

D) 2, 1, 3 (Respiration --> Photosynthesis --> neuron signaling)

Arrange the following sequence of procedures in the proper order in this experiment done to determine proteins present in pea plants during germination. 1. Load the proteins in polyacrylamide gel electrophoresis and separate them 2. Break the cells by grinding them in liquid nitrogen and suspending in a buffer 3. Select a suitable tissue to isolate proteins expressed only during germination 4. Centrifuge the broken cells to purify proteins from other molecules A) 1,3,2,4 B) 3,2,1,4 C) 2,4,1,3 D) 3,2,4,1 E) 2,4,3,1

D) 3, 2, 4, 1 (First step is to identify where you want the cells from. Then you have to break the cells to retrieve the proteins and centrifuge the components to isolate the proteins. Then you load the gel with the proteins and run it to separate according to size and charge.)

A high level of LDL (Low-density lipoprotein) - cholesterol found in blood (serum) is a major risk factor for heart disease. Such high cholesterol may be due to diet or genetic make-up. Which of the following may be the reason for a vegan to have high levels of serum LDL-cholesterol? A) Synthesis of cholesterol by liver B) Lack of membrane receptors to take up cholesterol C) Consumption of cholesterol in the vegan diet D) A and B E) A and C

D) A and B --> Synthesis of cholesterol by liver and Lack of membrane receptors to take up cholesterol

Cell Theory in its modern form includes all of the following postulates EXCEPT __________________ A) All organisms are composed of one or more cells. B) Cells are the smallest living things. C) Cells arise only by division of a previously existing cell. D) All cells contain nucleus E) Cell is the unit of life.

D) All cells contain a nucleus

In agarose gel electrophoresis, DNA or RNA fragments migrate towards ___________ end of the gel plate because of their____________. A) the neutral..... charge B) the anode ..... size C) the cathode ..... charge D) the anode ..... charge E) the neutral ..... size

D) Anode ... charge (The cathode in gel electrophoresis is negatively charged. RNA and DNA are negatively charged overall and are loaded into the cathode end of the gel. They move toward the positive end, anode (that attracts anions) because of negative charge.)

Which of the following is/are a highly specific mechanism(s) of cell transport? More than one answer possible, select one. A) Active transport B) Receptor mediated endocytosis C) Simple diffusion D) Both A and B E) All A, B and C

D) Both A and B --> Active transport and receptor mediated endocytosis

Which of the following components of cell membrane affects the selective permeability? A) Phospholipids only B) Proteins only C) Carbohydrates D) Both A and B E) A, B and C

D) Both A and B --> Phospholipids and proteins

Which of the following is the correct sequence of events in the origin of life? I. Synthesis of organic monomers II. Formation of prebiotic structures III. Synthesis of organic polymers IV. Formation of reproducible cells A) III, II, I, IV B) I, II, IV, III C) IV, III, I, II D) I, III, II, IV E) II, III, I , IV

D) I, III, II, IV

Which of the following is the right order of evolution of the following organisms? I) Plants II) Rodents III) Humans IV) Bacteria A) II, III, IV, I B) I, IV, II, III C) IV, II, I, III D) IV, I, II, III E) IV, III, I, II

D) IV, I, II, III

How does the double membrane structure of mitochondrion help in its function to make ATP? A) Stopping any molecules to go through mitochondrion B) Allowing only small molecules to go through the double membrane C) Controlling only polar molecules to go through D) Maintaining conditions within and between the two membranes to allow ATP synthesis E) Allowing only non-polar molecules to go through them

D) Maintaining conditions within and between the two membranes to allow ATP synthesis (The pH of the mitochondria is very important for ATP synthesis, and internal and external conditions need to be monitored closely for optimal functioning.)

Tasmanian tigers are extinct because of hunting by humans but the close relative Tasmanian devils are still alive and thriving well. If you were to use an adult cell's nucleus with intact DNA from a Tasmanian tiger to replace the nucleus of a Tasmanian devil's egg cell and make it produce to a new organism in a surrogate Tasmanian devils womb, what kind of organism will it make? A) Completely Tasmanian Tiger B) Completely Tasmanian Devil C) A hybrid with 50% of both organisms D) Mostly Tasmanian Tiger with the mitochondrial DNA from the T. Devil E) Mostly Tasmanian Devil with the mitochondrial DNA from T. Tiger

D) Mostly Tasmanian Tiger with the mitochondrial DNA from the T. Devil (The mitochondrial DNA is maternally inherited as it will come with the egg cell)

All the following are present in the biological membrane except_____________________ A) phospholipid B) sterols C) integral proteins D) oligosaccahrides E) polysaccharides

D) Oligosaccharides; E) Polysaccharides

We need to consume essential amino acids in our diet because we do not have ______________ that make essential amino acids. A) Mitochondria B) Ribosomes C) Lysosomes D) Plastids E) Glyoxysomes

D) Plastids (Plastids include chloroplasts and leucoplasts, which make essential amino acids)

Which of the following statements is/are true about the origin of life on earth? A) All life forms were created by some superhuman powers B) Life started with aliens spaceship bringing the first life forms C) Water bubbles in the air combined with minerals and formed life D) Simple molecules combined to make larger molecules and eventually the ancestral cells E) All life forms existed as it is present today ever since the earth was formed

D) Simple molecules combined to make larger molecules and eventually the ancestral cells

The digestive tract lining contains epithelial (outer lining) cells that do not allow food particles to randomly go inside the body except through specific proteins on their cell membrane. Which of the following structure blocks random diffusion of food particles between epithelial cells? A) Desmosomes B) Gap junctions C) Plasmodesmata D) Tight junctions E) Cell wall

D) Tight junctions (Tight junctions can fuse 2 cell membranes through integral membrane proteins (prevents any solutes from moving between the two cells))

When the cell's membrane potential reaches +30 mV, what should happen to restore the membrane potential to become -70 mV? A) Allow K+ to leave cell and Na+ to come in B) Transport Cl- to outside C) Transport both Na+ and K+ inside D) Transport K+ to outside

D) Transport K+ to outside (When cations such as K+ leave cell the inside become more negative and reaches -60mV)

What are the barriers for glucose to enter a bacterial cell from the medium? A) plasmamembrane --> cell wall --> capsule B) plasmamembrane --> capsule -->cell wall C) capsule --> plasmamembrane --> cell wall D) capsule --> cell wall --> plasmamembrane E) cell wall --> capsule --> plasmamembrane

D) capsule --> cell wall --> plasmamembrane

Fresh water protists such as paramecium maintain homeostasis of its salt concentration by pumping water out of the cell. Which of the following structures would serve this purpose? A) Large central vacuole B) Small central vacuole C) Proton pump D) Contractile vacuole E) Food vesicle

D) contractile vacuole (in fresh water protists, the vacuole will help remove excess water)

Read this paragraph and answer the question CYP3A4 is a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases that catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids, and other lipids components. The CYP3A4 protein localizes to the endoplasmic reticulum, and its expression is induced by glucocorticoids and some pharmacological agents. Cytochrome P450 enzymes metabolize approximately 60% of prescribed drugs, with CYP3A4 responsible for about half of this metabolism; substrates include acetaminophen, codeine, ciclosporin (cyclosporin), diazepam, and erythromycin. The enzyme also metabolizes some steroids and carcinogens. Most drugs undergo deactivation by CYP3A4, either directly or by facilitated excretion from the body. If someone is addicted to Oxycontin, shown below, which of the following enzymes and structures would try to detoxify them? A) cytochrome p450, lysosomes B) cytochrome p450, rough ER C) lysoszyme, mitochondrion D) cytochrome p450, smooth ER E) lysozyme, smooth ER

D) cytochrome p450, smooth ER (the smooth ER is responsible for chemical detoxification among other functions)

When freshwater plant cells are placed in sea water the cells will __________________________ A) absorb water, swell and burst. B) become turgid with the cell wall bulging out. C) become flaccid with stable cytoplasm inside cell wall. D) get plasmolyzed with water from cytoplasm leaking out. E) be stable with same solute concentration of solutes inside and outside

D) gets plasmolyzed with water from cytoplasm leaking out (Plasmolysis is when the cytoplasmic fluid is leaking out of the cell. This can happen when the cell goes into a hypotonic solution, such as sea water.)

Ion channel proteins are always ____________________________ A) glycoproteins with oligosaccharide attached B) lipoproteins with lipid attached C) soluble proteins in the cytoplasm D) integral membrane proteins E) peripheral membrane proteins

D) integral membrane proteins (Transmembrane proteins are integral protein that can form a channel for ions to go through the membrane.)

The major differences in the function of rough ER compared to smooth ER is to __________________ A) make steroid hormones B) synthesize phospholipids C) detox drugs D) make proteins E) make carbohydrates

D) make proteins (Rough ER has ribosomes attached to them, and they make proteins that are bound for the membrane or secretion)

Which of the following is not a common feature of both chloroplast and mitochondrion? A) Have their own DNA B) Make ATP C) Prokaryotic in nature D) Makes essential amino acids E) Make their own proteins and import some from cytoplasm.

D) makes essential amino acids (Essential amino acids are made only by chloroplasts as we need to consume them in our diet.)

Read the abstract of an article and then answer the following question. Development reaches a pinnacle during the onset of puberty for most brain regions. The neurotransmitter dopamine plays an important role in mediating and modulating stress responses within key brain regions. Age-related changes in the dopamine systems of the prefrontal cortex and the nucleus accumbens are involved in the maturation of acute and chronic stress responsiveness that is observed behaviorally. Exposure to chronic stressors before or during the onset of puberty during sensitive periods of dopamine development is likely to be involved in the rising prevalence of depression, anxiety, drug use, and schizophrenia that occurs in the transition between childhood and adolescence. What type of signaling mechanism is being described in the above abstract? A) direct contact B) paracrine signaling C) endocrine signaling D) synaptic signaling E) indirect signaling

D) synaptic signaling (Dopamine is a neurotransmitter sending signals to nervous system and affecting development during puberty.)

Which of the following pathway is the most probable pathway for secretory proteins that is glycosylated along the way? A) ER → Vesicle → nucleus → lysosomes → plasma membrane B) Nucleus → Smooth ER → Golgi apparatus → plasma membrane C) Golgi Apparatus → vesicles → lysosomes → plasma membrane D) Ribosomes → lysosomes → Golgi apparatus → plasma membrane E) Rough ER → vesicles → Golgi apparatus → plasma membrane

E) Rough ER → vesicles → Golgi apparatus → plasma membrane (Rough ER makes the protein, packages them into vesicles and the Golgi modifies the proteins and makes sure they are sent tot he plasma membrane for secretion)

Five dialysis bags (the synthetic membrane that do not allow glucose to go through) with various contents were placed in beakers with aqueous solutions. The bags were weighed before and after placing them in the beaker for 24 hours. Bag Dialysis Bag Content & Beaker content A 0.5 M glucose & Water B 0.75 M glucose & 0.5 M glucose C 1.0 M glucose & Water D 0.75 M glucose & 1.0 M glucose E Water & 1.0 M Glucose Which bag will lose the most amount of weight (net) after 24 hours incubation in the respective solutions? A) B) C) D) E)

E) (Water is the most hypertonic of the solutions. The bag with water would lose the most weight as the water goes into the 1.0 M Glucose, which is the most hypotonic solution.)

Which of the following structures are important for maintaining water pressure and movement of water in a tall plant? A) Desmosomes B) Plasma membrane C) Plasmodesmata D) Tight junctions E) Cell wall

E) Cell wall (Cell walls provide a rigid structure that can create an osmotic pressure to push water to a cell with less water)

What will happen if the segment of DNA coding for the target sequence is deleted from a gene encoding a protein located in lysosomes? A) Its mRNA will not be made in nucleus. B) .Its mRNA will not be processed properly. C) Protein synthesis will not happen for this mRNA. D) Once the protein is made, it will return to nucleus. E) It will not reach the target site, lysosome.

E) It will not reach the target site, lysosomes. (Target sequence is only one part of the protein and its absence will not allow the protein to reach its target, Lysosome.)

Refer to the ECG chart segment shown above and answer the following question (in the other ECG question) Which proteins will be responsible for the depolarization from Q to R? A) Na+-K+ pump moving 2 K+ in and 3 Na+ out B) H+ pump transporting protons inside C) ATP synthase pumping ATP outside D) Voltage gated K+ channel pumping K+ outside E) Voltage gated Na+ channel pumping Na+ inside

E) Voltage gated Na+ channel pumping Na+ inside

Plants can defend against grazers by producing ______________________ A) carbohydrates. B) proteins. C) lipids. D) DNA and RNA. E) secondary metabolites.

E) secondary metabolites (These are volatile and organic compounds that smell or taste bad.)

Give an example of how cytoskeletal elements helps in sexual reproduction of animals.

Sperm movement through flagella activity

What is a common mechanism to prevent any infection in all domains?

Physical barriers such as skin, cell wall, or capsule

What is the most active cell communication process happening in your body right now for you to see, hear and sense the surroundings?

Synaptic

When you are eating artificial sweeteners such as Splenda, which part of the signaling mechanism is primarily responsible to make you feel them as a sweet substance similar to table sugar?

The signal receptors will be the response to the sweetener. The sugar will touch the taste buds, which in turn will activate receptors to make substances as sweet similar to table sugar. (Splenda is a modified sucrose, called sucralose. It binds to taste buds (receptors for sweet substance) and triggers the response of tasting something sweet. The body cannot metabolize sucralose and it passes through the digestive system. The response of "tasting sweet" is due to the reception of the signal sucralose.)

What factors affect the diffusion of molecules in aqueous surroundings?

The size of the molecule and its charge

Lipids and carbohydrates do not have any charges associated with them, making it difficult to separate them by gel electrophoresis. What methods are good for separating such molecules?

Thin layer chromatography, gas chromatography, and mass spectrometry

How does a larger cell compensate for the reduced amount of surface area as the cell volume increases?

Through membrane folds and being highly compartmentalized

You are working for CDC and investigating a toxic E. coli contamination in lettuce. Which method(s) would be useful to definitely identify the toxic E. coli?

Use light microscope to find E. coli, use gel electrophoresis to find toxic protein, or use color imaging to investigate structure of the toxic E. coli

Animal viruses infect specific host cells and do not cross host range. This is because viruses are recognized and allowed inside cells through _______________________ A) Phagocytosis B) Pinocytosis C) Receptor mediated endocytosis D) Facilitated diffusion E) Exocytosis.

c) Receptor mediated endocytosis (Receptor proteins on cells are recognized and bound by proteins on viruses which trigger the endocytosis of the virus. Receptor is specific to the viral protein)

Bacteria and fungi can degrade wood because they can make the enzyme _________________________.

cellulase

What are some of the good pieces of evidence to understand evolution?

fossils, vestigial and homologous structures

Read the following paragraph. What types of symptoms would show in an individual with a defective mitochondrial genes? Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Each cell contains hundreds to thousands of mitochondria, which are located in the fluid that surrounds the nucleus (the cytoplasm). Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA. This genetic material is known as mitochondrial DNA or mtDNA. In humans, mitochondrial DNA spans about 16,500 DNA building blocks (base pairs), representing a small fraction of the total DNA in cells. Mitochondrial DNA contains 37 genes, all of which are essential for normal mitochondrial function. Thirteen of these genes provide instructions for making enzymes involved in oxidative phosphorylation. Oxidative phosphorylation is a process that uses oxygen and simple sugars to create adenosine triphosphate (ATP), the cell's main energy source. The remaining genes provide instructions for making molecules called transfer RNA (tRNA) and ribosomal RNA (rRNA), which are chemical cousins of DNA. These types of RNA help assemble protein building blocks (amino acids) into functioning proteins.

lack of energy (Mitochondrion is responsible for the production of ATP for cells. With a defective mitochondrial gene, ATP won't be produced as much, and a symptom of this would be lacking energy)

Read the following abstract and answer what type of information is/are needed for a protein to reach its destination within the cell. Protein targeting to subcellular organelles via mRNA localization. Cells have complex membranous organelles for the compartmentalization and regulation of most intracellular processes. Organelle biogenesis and maintenance requires newly synthesized proteins, each of which needs to go from the ribosome translating its mRNA to the correct membrane for insertion or translocation to an organellar subcompartment. Decades of research have revealed how proteins are targeted to the correct organelle and translocated across one or more organelle membranes to the compartment where they function. The paradigm examples involve interactions between a peptide sequence in the protein, localization factors, and various membrane-embedded translocation machinery. Membrane translocation is either cotranslational or posttranslational depending on the protein and target organelle. Meanwhile, research in embryos, neurons, and yeast revealed an alternative targeting mechanism in which the mRNA is localized and only then translated to synthesize the protein in the correct location. In these cases, the targeting information is encoded by cis-acting sequences in the mRNA ("Zipcodes") that interact with localization factors and, in many cases, are transported by molecular motors on cytoskeletal filaments. Recently, evidence has been found for this "mRNA-based" mechanism in organelle protein targeting to the endoplasmic reticulum, mitochondria, and the photosynthetic membranes within chloroplasts.

mRNA is localized and only then translated to synthesize the protein in the correct location. This mRNA-based mechanism, which involves mRNA sequences, will give targets to the ER, mitochondria, and photosynthetic membranes for proteins to target.

RNA considered being the first genetic material formed even before DNA because it can _________________ and ___________________________

store genetic information; replicate itself

While you swim in the pool, you do not absorb water and swell because the skin has_________________________.

tight junctions and selective permeability in the skin