Answer:
Explanation:
Thiamine pyrophosphate is a thiamine derivative and acts a coenzyme for various enzymes including pyruvate dehydrogenase and α-ketoglutarate dehydrogenase. These are involved in catabolism of pyruvate and α-ketoglutarate, respectively.
There is a gene in eukaryotes under the control of a transcriptional activator that ultimately regulates chromatin structure. This transcription factor requires dimerization to function. Given your understanding of how transcription factors work, list four different mutations that could disrupt the regulation of this gene and the functional consequences of these individual mutations. Consider both cis- and trans- acting elements and different protein domains.
Answer:
Mutation that prevents Transcription Factors Dimerisation
Mutation that prevents Transcription Factors from binding to Chromatin Remodeling proteins.
Mutation that prevents Transcription Factors from binding DNA
Mutation that prevents binding of co- activator
Explanation:
Several different mutations can affect Transcription Activators to be unable to promote transcription of its target gene:
1. Mutation that prevents Transcription Factors Dimerisation: In the given example, because the Transcription Factors requires dimerisation to function. A mutation that disrupts dimer formation will prevent the Transcription Factor from activating gene transcription.
2. Mutation that prevents Transcription Factors from binding to Chromatin Remodeling proteins: Since this transcription activator results in Chromatin remodeling, a mutation in the domain that binds to and recruits chromatin remodeling proteins will prevent the transcription factor from being able to promote chromatin remodeling.
3. Mutation that prevents Transcription Factors from binding DNA: A mutation that abrogates either the ability or the specificity of transcription Activator to bind to DNA will prevent the activator to effectively promote transcription of target gene.
4. Mutation that prevents binding of co- activator: Many activators promote transcription from a locus in the presence of a co-activator. A mutation that prevents the binding of the activator to the activator will prevent expression of the target gene.
When a plant encounters a pathogen, it initiates a series of complex signaling pathways that may result in being able to fend off future attacks by the same pathogen. This mechanism may be the closest process plants have to an immune system. Which of the following describes this process?
a) systemic acquired resistance
b) herbivore-induced plant volatility
c) reactive oxygen species generation
d) chromatin modification.
The correct answer is a) Systemic acquired resistance
Explanation:
In biology, systemic acquired resistance occurs as one organism develops resistance to a specific pathogen such as a virus or bacteria, this means, the organism's system recognizes previous pathogens it has been exposed to and in this way responds appropriately. The systemic acquired resistance occurs mainly in plants and due to this, it is believed this response is similar to one of the immune systems in animals. Therefore, the mechanism that is the closest process plants have to an immune system is Systemic Acquired Resistance or SAR.
"An experiment was performed to determine the role that ATP plays in kinesin movement along microtubules. Kinesin and microtubules were incubated together in a test tube, but instead of ATP, a non-hydrolyzable analog of ATP was added to the tube. What impact on kinesin function do you expect to observe in the presence of this ATP analog?"
Answer:
There will be no movement of kinesin motor protein along the microtubules .
Explanation:
Microtubules is an important component of cytoskeleton which play an important role in maintaining cell shape,cell motility,cell division regulation etc.
Whereas kinesin belongs to the family of motor proteins present in the eukaryotic cell.Kinesin plays an important role axonal transport.
The hydrolysis of ATP generates energy to power up the movement of kinesin along the microtubules.
According to the given question if kinesin and microtubules were incubated with an non hydrolyzable ATP analog instead of ATP,then the movement of kinesin along the microtubules will not occur due to lack of energy because the non-hydrolyzable analog of ATP cannot undergo hydrolysis to release energy.
The skin color variation of ___________ represents an increase in tissue bili/rubin from RBC destruction or liver cell destruction (hepat/itis). This color is best seen in the sclera of the eye, body membranes, and skin.
Answer:
Jaundice individual.
Explanation:
Jaundice may be defined as the medical condition in which the body of an individual turns into yellow. The different strains of the hepatitis virus is responsible for this infection.
The yellow color is deposited in the eyes, nails and membrane of the skin due to deposition of excess yellow orange pigment known as bilirubin. The alcohol can also cause the jaundice condition in the individual and destroys the proper liver functioning.
Thus, the answer is jaundice.
Vitamin K, one of the fat-soluble vitamins, plays a role in both bone health and blood clotting. There are two primary forms of the vitamin: phylloquinones and menaquinones. Choose the correct statement about vitamin K.a. Menaquinones are the primary form of vitamin K in the diet.b. Vitamin K deficiency inhibits the blood’s ability to clot.c. Excessive use of broad-spectrum antibiotics may cause vitamin K toxicity.d. The major source of vitamin K in our diets is from fortified grains.
Answer:
b. Vitamin K deficiency inhibits the blood’s ability to clot.
Explanation:
The main form is vitamin K1 (phylloquinone); followed by vitamin K2 (menaquinone), formed from the bacterial action on the large intestine tract and a third compound, vitamin K3 (menadione), a synthetic fat-soluble molecule. These vitamins can be found in many foods: in green vegetables (lettuce, cauliflower and spinach), in tomatoes, Brazil nuts, cashews, potatoes, contained in soybean oil, egg yolk, milk and to a lesser extent in wheat and oats.
Vitamin K participates in blood clotting, its deficiency can make it difficult to stop bleeding. Also causing damage to the body when in excessive concentration, for example: dyspnea (shortness of breath), and chest pain in adults with high vitamin K1 disorder and hyperbilirubinemia in newborns whose mothers in gestation underwent treatment with based on vitamin K3.
plasmodesmata are cell junctions that are found between ________. adjacent animal cells in the same tissue type individual cardiac cells in heart muscle tissue the plasma membrane of actively dividing prokaryotes
The question is incomplete. The complete question is:
Plasmodesmata are cell junctions that are found between ________.
a) adjacent animal cells in the same tissue type
b) individual cardiac cells in heart muscle tissue
c) the plasma membrane of actively dividing prokaryotes
d) adjacent plant cells
Answer:
d) adjacent plant cells
Explanation:
Plasmodesmata are the cytoplasmic channels that connect the adjacent plant cells together and maintain the continuity of their cytoplasm. These are the narrow channels with 20-40 nm diameter. Plasmodesmata serve the function analogous to the gap junctions of the animal cells. The presence of plasmodesmata between the neighboring plant cells allows the movement of molecules and ions between them. Plant cells can adjust the diameter of the plasmodesmata according to the requirement to allow the transport of substances across them.
Plasmodesmata are cell junctions found specifically between adjacent plant cells, facilitating transport and communication within plant tissues.
Explanation:The question relates to plasmodesmata, which are cell junctions found between adjacent plant cells. Plasmodesmata are channels that allow the transport of ions, small molecules, and macromolecules between the cytoplasm of adjacent cells, thus facilitating communication and transport of materials within plant tissues. They are found within the cell wall and are sheathed by the plasma membrane, which is an extension of the plasma membrane of adjoining cells. This intercellular connection raises the concept of plant tissue as a potential syncytium—a network of cells sharing a common cytoplasm.
In contrast, animal cells utilize gap junctions for similar cellular communication. Gap junctions are formed by the alignment of pores of connexons—complexes made of six proteins called connexins—between adjacent animal cells, which is particularly important in cardiac muscle tissue. However, these are not found in plants and thus not related to plasmodesmata, which are unique to plant cells.
On the other hand, prokaryotes, such as bacteria, lack specialized intercellular junctions because they do not have multicellular structures like eukaryotes. Instead, they may communicate through direct contact or by releasing and detecting signaling molecules.
The death cap mushroom, Amanita phalloides, contains several dangerous substances, including -amanitin. This toxin is a potent inhibitor of eukaryotic RNA polymerase II. Death, usually from liver dysfunction, occurs no earlier than several days after mushroom ingestion. Please speculate why
Answer:
Poisoning caused by the mushrooms like by eating Amanita phalloides can lead to the death of the organism after a few days. The chemical α- amanitin causes serious problems to humans as it shows its effect by inhibiting the RNA polymerase II enzyme which acts during the formation of mRNA.
If mRNA will not be formed, therefore the process of protein synthesis will not take place as a result, all the cellular processes will be halted and the organism will die.
The organisms do not die frequently after consumption of the mushroom instead dies few days only when the α- amanitin starts showing its effect on the liver and kidney and the liver and the kidney fails to perform their work.
Since the liver and kidney fails after a few days by the chemical α- amanitin, therefore, the organism dies after a few days.
The death cap mushroom contains α-amanitin, which inhibits RNA polymerase II, leading to delayed symptoms of poisoning such as liver dysfunction.
The death cap mushroom, Amanita phalloides, is notorious for its toxicity due to substances like α-amanitin. This particular toxin is a potent inhibitor of RNA polymerase II, which plays a crucial role in the synthesis of messenger RNA (mRNA) in eukaryotic cells. When α-amanitin inhibits RNA polymerase II, it disrupts the transcription process, eventually leading to cell death. However, the symptoms of poisoning, including liver dysfunction, do not manifest immediately because it takes time for a significant number of cells to be affected to the point of causing organ failure. Moreover, the body's compensatory mechanisms can temporarily mask the deterioration in function.
Endosymbiont theory explains some of the differences and similarities between prokaryotes and eukaryotes. Categorize the following statements as relating to prokaryotes or eukaryotes by dragging and dropping the labels below. Some labels might be used more than once.
a.Prokaryotes
i.Lack membrane-bounded
ii.These were the first organisms on Earth
iii.Includes organisms that are photosynthetic
iv.Aerobic bacteria are these types of cellsv.Includes organisms that carry out aerobic respiration
b.Eukaryotes
i.Have mitochondria ii.Might have chloroplastsiii.Includes organisms that are photosyntheticiv.Includes organisms that carry out aerobic respirationv.Cen be a multicellular organism
Answer:
Endosymbiont theory was proposed by Lynn Margulis in 1967 which suggested the origin of Chloroplast and mitochondria in eukaryotic cells.
The theory suggested that chloroplast and mitochondria organelle originated by engulfing the cyanobacteria and proteobacteria by other prokaryotic bacteria.
This shows that Prokaryotes exhibit the following characters:
1. These were the first organisms on Earth
2. Lack membrane-bounded
3. Aerobic bacteria are these types of cells
Eukaryotes exhibit:
1. Have mitochondria
2. Includes organisms that carry out aerobic respiration
3. Can be a multicellular organism
4. Includes organisms that are photosynthetic
5. Might have chloroplasts
Classify the steps involved in the formation of a solution as being endothermic or exothermic. separation of solute molecules separation of solvent molecules formation of solute-solvent interactions
Answer:
Endothermic reactions: separation of solute molecules , separation of solvent molecules
Exothermic: formation of solute-solvent interactions
Explanation:
An endothermic reaction can be described as a reaction which requires energy. Usually, the energy is taken in the form of heat from the environment. For example: the separation of solute and solvent molecules.
An exothermic reaction can be described as a reaction in which energy is released during a reaction. For example, a solute and a solvent reaction. Energy is usually released in the form of heat during an exothermic process.
Classifying the steps involved in the formation of a solution as being endothermic or exothermic:
endothermic
separation of solute moleculesseparation of solvent moleculesexothermic
formation of solute-solvent interactionsEndothermicIn this reaction heat or energy is absorbed in the process of producing the product. Breaking of bonds requires energy, so the separation term is endothermic.
separation of solute molecules and separation of solvent molecules both are endothermic.
ExothermicWith the product formation, energy or heat is also released in such a reaction. The interaction of solute solvent is exothermic as it releases heat in the process.
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DNA is different from RNA in that
A. RNA is made up five bases, whereas DNA is made up of four.
B. in general, RNA molecules are longer than DNA molecules.
C. RNA contains an additional oxygen atom on the ribose sugar.
D. RNA cannot exist as a double helix. All of these statements are true.
Answer:
RNA contains an additional oxygen atom on the ribose sugar. (Ans. C)
Explanation:
RNA contains a sugar which is known as ribose, and which contains an extra group of hydroxyl (OH-) while DNA contains deoxyribose sugar.
RNA contains four nitrogenous bases cytosine, adenine, guanine, and uracil, while DNA contains cytosine, adenine, guanine, and thymine.
Double helix means two stranded structure like DNA, while RNA is single stranded.
DNA molecule is much longer polymer than RNA molecule.
In general terms, normally a cell in your body crosses a checkpoint in the cell cycle when
A. It receives a "go-ahead" signal directly from your brain
B. Concentrations of proteins in the cytoplasm reach the appropriate level
C. It receives a "go-ahead" signal from your external environment
D. Concentrations of DNA in the nucleus reach the appropriate level
E. A mutation in the DNA occurs
Answer:
B. Concentrations of proteins in the cytoplasm reach the appropriate level
Explanation:
We can say that the cell cycle checkpoints is an important cell cycle control. In this regard, it is important to note that within a cell, the passage from one phase to another is controlled by regulatory factors that are characteristically proteinic and act at the so-called cell cycle checkpoints.
A cell passes the first checkpoint when protein concentrations in the cytoplasm reach the appropriate level.
the vertices of a triangle are (2,2),(4,4),and (4,2). Reflect the triangle in the y-axis. Give the coordinates of the reflected triangle
List and describe four stages/processes within a typical animal excretory system.
Answer:
The four stages of the excretory system are:
1. Filtration
2. Reabsoprtion
3. Secretion
4. Excretion
Explanation:
Filtration - Waste is taken out of the bodily fluids by pressure filtration
Reabsorption - Clean bodily fluids are reabsorbed back into the body/blood
Secretion - Adding of toxins and wastes from the body fluids to the filtrate
Excretion - Expulsion/release of the waste products out of the body through urine, sweating, etc
Final answer:
The four stages/processes within a typical animal excretory system are filtration, reabsorption, secretion, and excretion. During filtration, blood is filtered in the kidneys to remove waste products and excess water. Reabsorption involves the reabsorption of useful substances, while secretion eliminates waste materials. The final stage is excretion, where the urine is passed out of the body through the urethra.
Explanation:
The excretory system in animals is responsible for eliminating waste and excess water from the body. The four stages/processes within a typical animal excretory system include filtration, reabsorption, secretion, and excretion.
Filtration: In this stage, blood is filtered in the kidneys to remove waste products and excess water. Small molecules like water, glucose, amino acids, and ions pass through the filtration membrane, while larger molecules like proteins and blood cells are retained.
Reabsorption: During reabsorption, useful substances like glucose, amino acids, and ions are reabsorbed from the filtrate back into the bloodstream. This process helps maintain the body's essential nutrients and ions.
Secretion: Secretion involves the active transport of waste products, toxins, and excess ions from the bloodstream into the filtrate. This further helps in eliminating waste materials that were not filtered during the initial stage.
Excretion: The final stage of the excretory system is excretion, where the filtrate, now known as urine, is passed out of the body through the urethra. Urine is a concentrated solution containing waste products like urea, water, excess ions, and other substances.
Two related misconceptions about photosynthesis and cellular respiration are that only plants perform photosynthesis and that cellular respiration is performed in animals as the equivalent of photosynthesis. Explain why these statements are inaccurate. Be sure to provide an accurate description of the relationship between photosynthesis and cellular respiration.
Answer:
Photosynthesis and cellular respiration is not restricted to just plants and just animals.
Explanation:
Photosynthesis is the opposite reaction of cellular respiration. The equation for photosynthesis is:
6CO2 + 6H2O + (energy) ---> C6H12O6 + 6O2
If you reverse the reaction:
C6H12O6 +6O2 ---> 6CO2 + 6H2O + (energy)
You get the chemical equation for cellular respiration.
The relationship between photosynthesis and cellular respiration is that they are opposite reactions of one another.
One example of these reactions not being limited to their respected plants/or/animals is that photosynthesis is also performed by protists, which include algae and other single-celled organisms, that are technically not considered plants OR animals.
Another example is that plants also participate in the process of cellular respiration. Plants use photosynthesis to grow and produce glucose, and they use cellular respiration to break down the glucose formed from photosynthesis to release energy.
Answer:
Exactly the statement is incorrect because both organism needs respration for energy production thus it's not restricted to one organism,
Addition**
Respiration takes place at the mitochondria and both they have
What happens to pyruvate in the presence of oxygen? It enters the mitochondrial matrix and is converted to actyl CoA. It remains in the cytosol and is converted to ethanol. It remains in the cytosol and is converted to lactate. It enters the mitochondrial matrix and combines with oxaloacetate to form citrate. g
Answer:In glycolysis , Oxygen + Pyruvate molecules = acetyl-CoA + CO2
Where "=" means in the presence of enzyme complex pyruvate dehydrogenase complex (PDC)
Acetyl-CoA - NADH
Pyruvate oxidation or Pyruvate decarboxylation also known as link reaction, is the conversion of pyruvate into acetyl-CoA by the enzyme complex pyruvate dehydrogenase complex
Explanation:
A carboxyl group is trimmed off of Pyruvate and released as a molecule of carbon dioxide, leaving behind a two carbon molecule.
The two carbon molecule from above is oxidised - Acetyl group, and the electrons lost in the oxidation are picked up by NAD+ to form NADH
An acetyl group is transfered to Coenzyme A, resulting in acetyl CoA
Please help me!! I don’t understand
Answer:
The correct option is A. An airplane lifting into the sky during take- off.
Explanation:
The force of the gravitational pull is known to act downwards. The objects which will move along this force i.e will move downwards will have positive action.
A negative action will act against the gravitational pull i.e a force that is applied in the upward direction. As an aeroplane is lifted upwards during taking- off i.e against the gravitational pull of the earth hence it will be considered as a negative action.
In normal mitochondria the rate of electron transfer is tightly coupled to the demand for ATP. When the rate of use of ATP is relatively low, the rate of electron transport is low. When demand for ATP increases, electron-transport rate increases. Under these conditions of tight coupling, the number of ATP molecules produced per gram of oxygen consumed when NADH is the electron donor-the P/O ratio is about 2.5-3.0.
Ingestion of uncouplers causes profuse sweating and increase in body temperature. Explain this phenomenon in molecular terms. What happens to the P/O ratio in the presence of uncouplers.
An electron loses potential energy when it:
A. Shifts to a less electronegative atom
B. Shifts to a more electronegative atom
C. Increases its kinetic energy
D. Increases its activity as an oxidizing agent
E. Moves further away from the nucleus of the atom
Answer:
B that is electron Shifts to a more electronegative atom
Explanation:
Electron loses potential energy when Shifts to a more electronegative atom. In an reduction-oxidation reaction, when an electron comes in proximity of high electronegative atom, it tends to lose some energy in form of potential energy. Electrons have more energy potential when associated with less electronegative atoms (such as C or H) and less energy potential when associated with a more electronegative atom (such as O).
hence the correct answer is B that is electron Shifts to a more electronegative atom
An electron loses potential energy when it shifts to a more electronegative atom, as the increased attraction to the atom's nucleus lowers potential energy and stabilizes the system.
Explanation:An electron loses potential energy when it shifts to a more electronegative atom. Electronegativity refers to the ability of an atom to attract electrons. When an electron moves from a less to a more electronegative atom, the electron is drawn closer to the atom's nucleus, resulting in a decrease in potential energy. This is because a more electronegative atom exerts a stronger pull on the electron, stabilizing the system by lowering the electron's potential energy.
Moreover, within an isolated atom, an electron loses potential energy when it moves closer to the nucleus (n decreases), making the system more stable and the atom ionized to a lower energy state if it captures an electron. This entire process enables the cell to incrementally use energy through the movement of high-energy electrons, which is crucial for metabolic pathways and the extraction of energy from food.
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If skeletal muscles work to the point of fatigue, the muscle cells may not have sufficient oxygen to carry out aerobic respiration. What processes do muscle cells use if oxygen is not available for aerobic respiration?a. lactic acid fermentation b. citric acid cycle c. ethanol fermentation d. glycolysis
Answer:
a. lactic acid fermentation
Explanation:
Under conditions of intense exercise, the oxygen gas obtained by pulmonary respiration may be insufficient to meet the needs of muscle cells in the work of obtaining energy from cellular respiration.
However, even in the absence of oxygen gas, our muscle cells can release the available energy in glucose, leading to even smaller amounts of ATP molecules. Under these conditions, muscle cells perform lactic fermentation, a process that is virtually identical to glycolysis (the first set of cellular respiration reactions), except that pyruvic acid is transformed into lactic acid with the formation of 2 ATPs. Despite the lower energy yield, fermentation ensures the energy supply to the muscle. Lactic acid formed under these conditions has been associated with muscle pain and fatigue characteristic of intense physical exercise. Recent research, however, has shown that pain is caused by muscle fiber micro-injuries rather than lactic acid as it is rapidly metabolized and eliminated.
g As a second step in thenerd-proposal, Wouldbe Fiancé needs to obtain DNA fragments that are the right size to make up the letters spelling out "Will you marry me?" How would they do that? A)Use restriction enzymes to cut the DNA at specific sequence sites. B)Waitfor helicase to unzip the genes. C)Use DNA ligase to stick together the Okazaki fragments. D)Alter the reading frame of the mRNA.
Answer:
A)Use restriction enzymes to cut the DNA at specific sequence sites.
Explanation:
Restriction enzymes cut DNA in specific sites. There are high and low frequency endonucleases. The easiest to get fragments to make the words: WILL YOU MARRY ME? is to amplify PCR fragments of known size and sequence, therefore, use restriction enzymes to cut the fragments of the desired size. It will be very useful make an in silico digestion to predict all the fragment sizes to be obtained, and a simulation of the gel before loading it.
Why are non-native tree diseases and insects often so much more virulent than their native counterparts?
Answer:
Non-native plants reduce the diversity of insect populations in gardens, even where the non-native plants are closely related to the native plants, new research shows. ... local insect communities than their non-native counterparts,
Explanation:
Non-native tree diseases and insects can be more virulent in new environments due to factors like the absence of natural predators, a lack of host plant resistance, fewer competing species, and escape from natural constraints.
What happens with the diseasesAdditionally, they may lack genetic diversity, undergo rapid evolution, and be spread by human activities.
These factors, combined with the vulnerability of non-native ecosystems, make them more destructive in their new environments, requiring various strategies to manage their impact.
We can conclude that the reason is because these trees do not competitors as well as the absence of predators that may have destroyed the species.
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A redwood tree, Sequoia sempervirens is hexaploid with a total of 66 chromosomes. Considering this, how many chromosomes did the tree inherit from each of it's parents? How many chromosomes can be expected to be in each of its gametes? How many chromosomes are likely to be in each somatic cell of the tree's offspring?
Answer:inherited 33 chromosomes from each parent; gametes have 33; somatic cells of offspring 66.
Explanation: S. sempervirens is sn autohexaploid, as were its parents. It inherited 33 chromosomes from each parent, and that is the chromosome number in its gametes, which means its offspring’s somatic cells will have 66 chromosomes
During the dissection, you used your hands to follow the digestive tract anteriorly and posteriorly. Outline the path that food takes through the frog’s digestive tract: start at the mouth, indicate the major organs through which food passes, and end at the cloaca
Final answer:
Food in a frog's digestive system flows from the mouth, through the pharynx, esophagus, and stomach, into the small intestine for nutrient absorption, then to the large intestine for water absorption, and finally out through the cloaca as waste.
Explanation:
The path that food takes through a frog's digestive tract begins at the mouth where ingestion occurs. From there, food moves into the pharynx, then down through the esophagus and into the stomach where preliminary digestion takes place. After the stomach, food enters the small intestine where nutrients are absorbed. It then proceeds into the large intestine, where water is absorbed, and finally, the undigested waste products are expelled through the cloaca.
ANSWER THIS ASAP WILL MARK BRAINLIEST EXTREME POINTS ANSWER NUMBER 21 ONLY
Answer:
dendrites
Explanation:
The neuron consists of a cell body and extensions called dendrites. In some neurons, one of the dendrites is elongated to form an axon. There are terminal and receptor dendrites. Receptor dendrites make contact with terminal dendrites of neighbouring neurons or receptor organs while terminal dendrites make contact with receptor dendrites of another adjacent neurons or effector organs.
You treat bacteria with an extract made from peanuts that had a fungus growing on it. You then plate 10s of these bacteria onto a plate that contains penicillin. As a control you leave out peanut extract. You obtain 2 colonies from the control and 3 colonies after treatment with the corn extract. You conclude:
A. The peanut extract is not mutagenic.
B. The peanut extract is mutagenic.
C. Penicillin is mutagenic.
D. None of the answers listed above (ABC) are correct.
Answer:
C. Penicillin is mutagenic.
Explanation:
Mutagens are agents that change genetic material. They multiply the frequency of mutations of an organism over their standard level. The peanut extract that was left as control shows this natural or standard level, but when tenths of these bacteria were put into a plate that contained penicillin, the bacteria colonies increased the frequency of mutations of these bacteria after a determined time.
As described in Investigating Life 20.1, scientists found that the range of the alpine chipmunk has shifted about 500 meters up in elevation, leading to isolated subpopulations on individual mountaintops. According to the researchers, what has caused this shift?
A.harmful UV radiation due to the ozone holeB.habitat destruction due to acid precipitationC.introduction of nonnative speciesD.climate warming due to increased CO2 concentrations
Final answer:
The shift in the Alpine chipmunk's range is caused by climate warming due to increased CO₂ concentrations, pushing species to higher elevations.
Explanation:
According to researchers, the shift in the Alpine chipmunk's range upwards by about 500 meters, resulting in isolated subpopulations on individual mountaintops, is primarily due to climate warming due to increased CO₂ concentrations. This conclusion is based on the observation that, globally, many species are moving towards higher altitudes or latitudes in response to changing climate gradients. With the warming climate, species adapted to colder environments find their habitable zones moving uphill. As a result, these species, including the Alpine chipmunk, are forced to follow the shift in their preferred climate range, leading to higher elevations and, unfortunately, potential habitat isolation and range restriction.
A drug that prevents disassembly of the mitotic spindle would stall the cell cycle
A. in the middle of G1
B. just before DNA replication
C. just before chromosome condensation
D. just before or just after the separation of sister chromatids
E. at the G2 checkpoint
Answer:
D. just before or just after the separation of sister chromatids
Explanation:
The mitotic spindle is a structure of the eukaryotic cell cytoskeleton involved in mitosis. Their function is to separate the sister chromatids during cell division so that they are included in the daughter cells. It consists of longitudinally aligned microtubule bundles that together have an ellipsoid-like shape.
For this reason, we can state that if a drug that prevents disassembly of the mitotic spindle paralyzes the cell cycle immediately before or shortly after separation of the sister chromatids.
Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane? a. rRNAb. ribosomal proteins c. mRNA d. phospholipids
From the following macromolecules which enter the nucleus of a eukaryotic cell through pores in the nuclear membrane is mRNA. The correct option is c.
Macromolecules are big molecules, such as proteins, that are usually formed through the polymerization of smaller subunits known as monomers.
The nuclear pore is a conduit in the nuclear envelope that is lined with proteins. The nuclear pore controls the movement of molecules between the nucleus and the cytoplasm. The nucleus in eukaryotic cells is isolated from the cytoplasm and surrounded by a nuclear envelope.
mRNA is generated by DNA during the transcription process. Following synthesis, the newly formed molecule goes from the nucleus to the cytoplasm. A nuclear pore allows it to pass through the nuclear membrane. It will then connect with a ribosome, which is just coming assembled from two subunits, one large and one little.
Thus, the correct option is c.
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C)mRNA is the macromolecule that enters the nucleus of a eukaryotic cell through the pores in the nuclear membrane.
The nuclear pores allow large molecules such as mRNA transcribed from genes in the DNA to leave the nucleus and enter the cytoplasm to participate in protein synthesis.
Additionally, the RNA components of ribosomes are synthesized in the nucleolus, and after being produced, ribosomes are exported to the cytoplasm.
Human skin cells typically have 46 chromosomes. A human skin cell in G2 phase has ___________ chromosomes, ____________ chromatids, and ______________ DNA molecules.
A. 92 92 46
B. 46 92 92
C. 23 46 46
D. 46 46 46
E. 23 23 23
Answer:
B. 46 92 92
Explanation:
The cell cycle consists of three states: Interphase, cell division and Resting.
The interphase is composed of the pases G1, S and G2 (in this order), through which the cell prepares itself for the cell divison, where a single mother cell generates two (by mitosis) or four daughter cells (by meiosis).
As part of the preparation, the cell duplicates during the interphase all its genetic material (specifically in the phase S), forming replicated chromosomes. That is to say, a chromosome with two chromatides (sister chromatides).
A human cell that normally has 46 chromosomes will have in the G2 phase the same number of chromosomes: 46, however, these chromosomes will be composed of two chromatids (instead of a single one as normally), and therefore the cell will have 92 chromatides.
Because a chromatide is made up of a strand of DNA, in the G2 phase the cell will have also 92 DNA molecules.
Due to the phenomenon of dominance,
A) different genotypes can give different characters.
B) different genotypes can result in the same phenotype.
C) the same genotype can produce different phenotypes.
D) the same genotype can produce different characters.
E) the same phenotype can produce different genotypes.
Answer:
The correct answer will be option-B
Explanation:
Dominance is the phenomenon observed in the genes coding for a trait in which the one variant of a gene called allele masks the effect of a complementary allele at same locus coding for the same trait.
The concept of dominance was observed by Gregor Mendel during his experiments on Pea related to study the inheritance pattern.
Since in dominance, one allele masks the effect of complementary allele therefore the dominant allele shows its effect and different genotypes produce the same phenotype.
Thus, Option-B is the correct answer