Final answer:
For identical twins, if one sibling has anorexia nervosa, there is up to a 50-75% chance the other will as well, in contrast to a 20% chance for fraternal twins, highlighting a genetic component in the disorder's development.
Explanation:
If one identical twin suffers from anorexia nervosa, the likelihood that the other twin will develop this disorder is significantly higher than in fraternal twins. While the exact percentage can vary, studies have shown a higher concordance rate among identical twins compared to fraternal twins, with rates up to 50-75% in identical twins and around 20% in fraternal twins for eating disorders like anorexia nervosa.
Anorexia nervosa is an eating disorder characterized by a fear of gaining weight and a severe restriction of food intake which can lead to extremely low body weight and a distorted body image. Treatment aims for recovery, which includes establishing normal eating habits and reaching a healthy weight. Genetic factors, along with environmental influences, play a critical role in the development of anorexia nervosa, and this is partly illustrated by the differences in concordance rates between identical and fraternal twins.
The enzyme phosphofructokinase catalyzes the conversion of fructose-6-phosphate and adenosine triphosphate (ATP) to fructose 1,6-bisphosphate and adenosine diphosphate (ADP). Adenosine monophosphate (AMP) activates the enzyme phosphofructokinase (PFK) by binding at a site distinct from the substrate-binding site. This is an example of:__________.
Answer: Allosteric activation
The enzyme phosphofructokinase catalyzes the conversion of fructose-6-phosphate and adenosine triphosphate (ATP) to fructose 1,6-bisphosphate and adenosine diphosphate (ADP). Adenosine monophosphate (AMP) activates the enzyme phosphofructokinase (PFK) by binding at a site distinct from the substrate-binding site. This is an example of allosteric activation.
Explanation:
The enzyme, phosphofructokinase is an allosteric enzyme since it possess more than one active site. The other active site is called an allosteric site.
Thus, since AMP binding at the allosteric site of PFK increases its affinity for its substrate (fructose-6-phosphate and ATP) conversion, then it is said to be an example of allosteric activation.
Use the information from the article to answer the question.
Asteroids and Comets
Which statements describe the characteristics of asteroids? Check all that apply.
formed 4.6 billion years ago
orbit the Sun beyond Jupiter
range in size from a few feet to more than 300 miles across
have a total mass greater than the mass of the moon
most are found in the asteroid belt
Answer: Formed 4.6 billion years ago and most are found in the asteriod belt
Explanation:
Answer:
1.)formed 4.6 billion years ago 3.)range in size from a few feet to 300 miles across 5.) most are found in the asteroid belt
Explanation:
read the article provided
What type of force does a backpack exert on the body’s back and hips?
tension
compression
flexion
extension
Answer:
Compression
Explanation:
Backpack cause strain in one's neck, back and shoulders especially when it is loaded with load, the weight's force pull backward. In order to compensate for the force we bend forward at the hips or arch our back and this causes the spine to compress unnaturally.
Answer:
compression
Explanation:
plato/ edmentum
In positive control of several sugar metabolism-related operons, the cAMP receptor protein (CRP) binds to DNA to stimulate transcription. Which of the following environmental conditions causes an increase in CRP activity in stimulating transcriptionCorrect a decrease in glucose and an increase in cAMP
Answer:
CRP (cAMP receptor protein) is a protein found in bacteria. It is a regulatory protein.
Explanation:
CRP binds to cAMP which brings the conformational change which leads to the binding of CRP to specific sites on DNA promoter. This activates the transcription through interaction with RNA polymerase. Decrease in glucose and increase in cAMP causes an increase in CRP activity. cAMP is low when glucose behaves as a carbon source. This is due to inhibition of adenylate cyclase enzyme (cAMP producing enzyme). So, a decrease in glucose level will increase cAPM level.
A bacterial cell is suddenly expelled from a warm human intestine into the cold world outside. Which one of the following adjustments might the cell make to maintain the same level of membrane fluidity that the cell had in the intestine?a. increase the length of the hydrocarbon tails in its membrane phospholipids.
b. increase the proportion of unsaturated hydrocarbon tails in its membrane phospholipids.
c. increase the proportion of hydrocarbon tails with no double bonds in its membrane phospholipid.
d. decrease the amount of cholesterol in the membrane.
Answer:
b. Increase the proportion of unsaturated hydrocarbon tails in its membrane phospholipids.
Explanation:
A bacterial cell in the warm human intestine that has been expelled into the cold world outside has to increase the proportion of unsaturated hydrocarbon tails in its membrane phospholipids to be able to maintain the level of membrane fluidity it experienced in the intestine.
This is because membrane phospholipids are unsaturated fatty acids that have more double bonds and a shorter hydrocarbon tail which prevents them from been tightly packed together thereby increasing the fluidity of the phospholipids in the bacterial cell.
Answer:
b. increase the proportion of unsaturated hydrocarbon tails in its membrane phospholipids.
Explanation:
Fluidity of the plasma membrane depends on the fluctuations of the structure of its cholesterol, length of the fatty acid chains and the extent of saturation.
Thus fluidity is encouraged by;
Increase in unsaturation of the fatty acids tails. The more unsaturated the chain, the' more bent' or 'kink' they are and therefore the less aligned, and therefore more fluidity. Since unsaturation favours fluidity the answer is B.
The short the fatty acid tails; shorter tails are less packaged together they therefore promote fluidity. longer chains gives close packing encouraging rigidity.
Option c, is reducing unsaturation,but promoting saturation which does not favour rigidity, therefore very wrong.
option d, is wrong because increasing cholesterol levels promotes fluidity by preventing close packing. Therefore, decreasing it favours rigidity.
A migratory bat species pollinates agave plants in northern Mexico on its way to the southwestern United States where it spends the summer eating insects and reproducing. Farmers spraying pesticides affect these bats, which eat the insects and also feed them to the baby bats. This could be the start of a story about ________.
-threats to a keystone species
-an extirpation
-insect biodiversity
-sustainable agriculture
-an umbrella species
Answer:
Threat to a keystone species
Explanation:
Keystone species are organisms that play a unique and crucial role within the ecosystem, that is, regulating the environment to help maintain a balanced habitat. Removing these organisms will result in an unbalanced ecosystem, this will affect other organisms and can lead to biodiversity degradation.
The parents of a 13-year-old boy with a sore throat for a week, vomiting for two days, swollen lymph glands, and stiff achy joints is now seeking antibiotic treatment after herbal remedies were unsuccessful. Throat cultures reveal infection with group A streptococci. This child is at high risk for development of which cardiac complicaton?
ANSWER: MITRAL VALVE STENOSIS
EXPLANATION:
The child have the risk of having MITRAL VALVE STENOSIS. It is also referred to as mitral stenosis.
Mitral valve stenosis occurs as results of the mitral valve opening narrowing. Which effect to less blood flowing through it.
The mitral valve is located between two chambers (the atrium and the ventricle) on the left side of your heart.
However, Mitral valve stenosis can lead to different health issues, including blood clots, difficulty breathing, fatigue, and heart failure.
Mitral valve stenosis is specifically caused by rheumatic fever (a childhood disease). This rheumatic fever occurs has a result of the body's immune response to an infection associated with the streptococcal bacteria.
Acute rheumatic fever affects the joints and the heart greatly. It causes joints inflammation temporarily and in severe case causes chronic disability.
Nevertheless, this cardiac complication have treatment and it is based on whether the affected individuals shows symptoms. Medications like blood thinners or anticoagulants (to reduce the risk of blood clots), diuretics, antiarrhythmics (to cure abnormal heart rhythms), beta-blockers (to slow your heart) etc, are being administered based on the level of the complication.
When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of:___________.A) cancer.B) cell constraint.C) density-dependent inhibition.D) cell division repression.E) growth factor desensitization.
Answer: C) density-dependent inhibition
Explanation: When density is high. cell division is inhibited. Density-dependent inhibition occurs when cells grow to a limit and the density of the area is high, growth becomes inhibited as a result of competition for nutrients, space and growth factors. When such arises, the cells get a notification to stop division.
Emma is having a tea party with her stuffed animals and dolls, and pretends that they love the tea and cookies she prepared. Emma's belief that her stuffed animals and dolls are alive and hold human qualities is an example of ____.
Answer:
The correct answer is animism.
Explanation:
The concept that all the things whether living or non-living, comprising human beings, geographic features, animals, natural processes, and other non-living entities exhibits life, which associates them with each other is termed as animism. Animism is a belief that helps in determining general associations of holiness amongst the various systems of beliefs.
Animism generally has an application in explaining the differences between ancient beliefs and present organized religion. In the majority of the situations, animism is not regarded as a religion, however, a characteristic of different beliefs and practices. Thus, the given case is an illustration of animism.
based on observational evidence, variations in the color of flamingos appears to be determined by their diet, an not their genes. Describe the steps of an investigation to provide evidence to support or refute this hypothesis.
In order to make a proper investigation using the scientific method we have to follow the following statements.
Create three or more groups of flamingos. One control group were the flamingos will be fed by their occasional diet. A second group with a diet with no artificial or natural dye, as β-Carotene, which is high present in seaweeds. The third group will have a diet with a high amount of β-Carotene. The color of the groups will be analyzed to see the changing of pigmentation by time. If the group which is fed by B-Carotene increases the pigmentation, it might indicate a diet factor. As counterproof, a sample of DNA of the groups has to be taken. If is there any pattern between the groups of no-colored flamingos and a pattern of colored ones. It can indicate a genetic factor. If not, the diet can be responsible for it.It is possible to carry out genetic crosses in order to observe the phenotypic proportion in offspring and thus confirm genetic inheritance.
Genetic inheritance can be traced by observing the proportion of offspring in a given cross.In diploid organisms, individuals receive two alleles (or gene forms) for a given gene locus.In complete dominance, the dominant allele completely masks the expression of the recessive allele in heterozygous individuals.In conclusion, it is possible to carry out genetic crosses in order to observe the phenotypic proportion in offspring and thus confirm genetic inheritance.
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In certain cancers, the GTPase activity of the RAS G-protein is inhibited. This means that the RAS protein can no longer hydrolyze GTP into GDP. What effect would this have on downstream cellular events?
Explanation:
The epidermal development factor (EGF) receptor (EGFR) is a receptor tyrosine kinase associated with the guideline of cell development, wound mending, and tissue fix. When EGF ties to the EGFR, a course of downstream occasions makes the cell develop and isolate. In the event that EGFR is actuated at improper occasions, uncontrolled cell development (malignancy) may happen. After the ligand ties to the phone surface receptor, the initiation of the receptor's intracellular parts sets off a chain of occasions that is known as a flagging pathway, here and there called a flagging course. In a flagging pathway, second delivery people catalysts and enacted proteins interface with explicit proteins, which are thus initiated in a chain response that in the long run prompts an adjustment in the cell's condition For example, an expansion in digestion or explicit quality articulation. The occasions in the course happen in an arrangement, much like an ebb and flow streams in a waterway. Collaborations that happen before a specific point are characterized as upstream occasions, and occasions after that point are called downstream occasions.The closest living relative of P. chromatophora is the heterotroph, P. ovalis. P. ovalis uses threadlike pseudopods to capture its prey, which it digests internally. Which of the following, if observed, would be the best reason for relabeling P. chromatophora as a mixotroph? // as a mixotroph instead of an autotroph?
A) a threadlike pseudopod
B) a pigmented central vacuole, surrounded by a tonoplast
C) a vacuole with food inside
D) a secretory vesicle
E) a contractile vacuole
Answer:
Option-(C): A vacuole with food inside.Explanation:
The plant cells consists of the different organelles which are required to maintain the optimum level of food productivity to drive the different processes inside the environment and maintains the balance for the conservation of energy inside the environment or any space. As, the vacuoles are there either to store food resources or has the capacity to store the required amount of enzymes for the sake of digestion of food materials and other substance which enters the plant cell, while the enzymes are there to digest the macro-molecules into the basic components.What is a product from fatty acid oxidation of palmitate?
Answer: Acetyl coA
Explanation:
The beta-oxidation of palmitate (hexadecanoic acid); one of the most common saturated fatty acids, occurs in the mitochondria and yields 8 molecules of Acetyl-coA that then enters the citric acid cycle and electron transport system to yield ATP.
The bacterial species Staphylococcus aureus is found on the skin and in the nasal passages of about 20% of the human population. In healthy individuals, S. aureus is benign (does not cause harm) in these locations. However, if it is introduced into the bloodstream through, for example, a wound, it can make a person gravely ill. Thus, the ecological relationship of S. aureus with a human:______________
Answer:
The ecological relationship of Staphylococcus aureus with a human can be mutualistic or antagonistic.
Explanation:
Mutualism is a type of ecological interaction. It occurs between 2 individuals in which each individual has a net benefit.
Antagonism is the opposite of Mutualism. It also occurs between two individuals but in this case one specie is getting the advantage at the expense of the other specie.
The greater the mass of tissue in an organ, the greater its need for an adequate blood supply. Which chamber of the heart has the highest probability of being the site of a myocardial infarction?
Left ventricle .
Explanation:
Myocardial infarction commonly known as heart attack occurs when there is inadequate supply of blood to the heart.
Since the left ventricle of the heart is much thick when compared to other chambers, its oxygen demand is much more. To fulfill this oxygen demand it needs maximum supply of oxygenated blood.
Thus if the blood supply to heart is lowered due to any reason then the left ventricle will be affected at first becoming the most probable site of myocardial infarction.
The left ventricle has the highest probability of being the site of a myocardial infarction because it requires a significant amount of blood to supply its thick muscular walls, making it more vulnerable to disruptions in blood supply.
The chamber of the heart with the highest probability of being the site of a myocardial infarction is the left ventricle. This is because the left ventricle has a greater mass of tissue than any other chamber within the heart, due to its role in pumping oxygenated blood to the systemic circulation, which requires considerable force to reach the farthest points of the body, like the toes. The left ventricle's thick muscle walls need an adequate blood supply to function, making it more vulnerable to damage if the supply is disrupted, such as by a blockage in the coronary arteries that feed the heart muscle. Myocardial infarction, commonly known as a heart attack, occurs when cardiac muscle cells die due to a blockage of a coronary artery, halting the blood flow and the oxygen supply to that part of the heart muscle.
When a variegated female four o'clock plant is crossed with any male plant, progeny plants can have either green, white, or variegated leaves. Which of the following statements correctly explain this result? Select all that apply. a.The female plant produces some gametes that are homoplasmic. b.The female plant is heterozygous. c.The female plant produces some gametes that are heteroplasmic. d.The female plant is homozygous in some cells and heterozygous in other cells. e.Leaf phenotype is determined by the number of normal or mutant chloroplasts inherited from the female parent.
The correct statements are
a.The female plant produces some gametes that are homoplasmic.
c.The female plant produces some gametes that are heteroplasmic.
e.Leaf phenotype is determined by the number of normal or mutant chloroplasts inherited from the female parent.
Explanation:
The results clearly indicated that the phenotype of the progeny was clearly dependent on the female parent.
This is because the females have egg cells which are larger than the male’s pollens. Due to this large size, female egg cells have cellular organelles like mitochondria, chloroplasts etc; whereas, the smaller male cells are devoid of any organelle.
The variegation in a leaf depends upon the chloroplasts present in it and since only the female cells contain chloroplasts. The appearance of the green color depends upon the chlorophyll in the chloroplasts.
Hence when green leaves were propagated, the progeny also had green leaves. This clearly proves that the leaf phenotype is based on the female parent’s chloroplasts and homoplasmic or heteroplasmic phenotypes are accordingly produced in the progeny due to the female parent.
The female plant cannot be homozygous in some cells or heterozygous in other cells and need not be only heterozygous; the phenotype of the gamete only differs according to the female parent.
Human activities, including fossil fuel combustion, farming, and deforestation, are known to increase the levels of carbon dioxide, methane, and nitrous oxides in our atmosphere. Measurable warming of Earth due to these greenhouse gases can alter ecosystem dynamics. In addition to the direct climatic effects on organisms within biomes, warming can lower levels of sea ice and increase precipitation in Arctic areas. Global warming can also melt permafrost in the tundra and increase sea surface temperatures, which could increase the intensity of hurricanes in vulnerable areas. Within communities, climatic change can shift interdependent species "out of sync," potentially causing indirect loss of species. For example, if pollinators and the plants they pollinate become out of synch, the pollinators may not be able to switch to a different food source, and the plants may not be able to reproduce. If the climate warms significantly, tundra permafrost may melt, which may lead to ________ the community.
Answer:
succession occurring in the community
Explanation:
Succession: a number of persons or things following one another in order or sequence.
A domino affect
EEG studies of the neocortex suggest that the __________ frontal lobe is more active when a person wants to approach something pleasant, while activity in the __________ frontal lobe is associated with wanting to withdraw from something unpleasant.
The CNS communicates with peripheral body structures through pathways. These conduct either sensory nerve signals from ____________ or motor nerve signals to ____________ ; processing and integration occur along them. These pathways travel through the white matter of the spinal cord as they connect various CNS regions with spinal nerves. A pathway consists of a(n) ____________ (groups or bundles of axons that travel together in the CNS) and a(n) nucleus (a collection of neuron cell bodies located within the CNS).
Answer:
receptors, effectors, tract
Explanation:
first is receptor because we have to sense the stimulus for our brain to send signal to certain parts or effectors to act on it. The third blank is tract because it serves the definition of tract which says a tract major passage in the body, large bundle of nerve fibers, or other continuous elongated anatomical structure or region.
The central nervous system communicates with the body through pathways in the spinal cord that connect the CNS with peripheral nerves. These pathways consist of tracts and nuclei.
Explanation:The central nervous system (CNS) communicates with peripheral body structures through pathways. These pathways conduct either sensory nerve signals from the body or motor nerve signals to the body, while processing and integration occur along them. These pathways travel through the white matter of the spinal cord as they connect various CNS regions with spinal nerves.
A pathway consists of tracts (groups or bundles of axons that travel together in the CNS) and a nucleus (a collection of neuron cell bodies located within the CNS).
Which of the following is most similar in structure to ATP?
A) a pentose sugar B) a DNA nucleotide C) an RNA nucleotide D) a phospholipid E) an amino acid with three phosphate groups attached
Explanation:
Nucleic acids, DNA or deoxyribonucleic acid and RNA or Ribonucleic acid are the biological macro-molecules formed by the polymerization of monomeric units called Deoxy-ribonuclotide and Ribonucleotide respectively.Each nucleotide or deoxy-ribonucleotide is comprised of: A pentose sugar, deoxyribose for DNA and ribose for RNA. The Ribose has a hydroxyl group at the 2' carbon position of the sugar molecule. This hydroxyl group is replaced by hydrogen in the deoxyribose sugar.A nitrogenous base, like adenine, guanine, cytosine and thymine (for DNA) and uracil (for RNA) linked to the 1' carbon of the deoxyribose or ribose sugar through glycosidic linkage.One phosphate group which forms a phosphodiester bond in between the 3' carbon of one sugar molecule with the 5' carbon of the next sugar molecule in the nucleic acid polymer.An ATP molecule contain: Ribose as the pentose sugar but not deoxyribose.The nitrogenous base here is Adenine.Three phosphate groups, alpha, beta and gamma, linked to each other by two phospho-anhydride bonds and to the ribose sugar by one phosphate-ester bond.The ATP molecule loses two of its phosphate groups, the beta phosphate and the gamma phosphate, and forms a phosphodiester bond between the 3' carbon of one ribose sugar molecule and the 5' carbon of the next ribose sugar molecule in the Ribonucleic acid polymer.Final answer:
The structure most similar to ATP is an RNA nucleotide because both have a nitrogenous base, a ribose sugar, and phosphate groups.
Explanation:
Among the choices provided, the one that is most similar in structure to ATP (adenosine triphosphate) is C) an RNA nucleotide. Both ATP and an RNA nucleotide consist of three parts: a nitrogenous base, a five-carbon sugar (ribose), and phosphate groups. An RNA nucleotide has a ribose sugar, a nitrogenous base, and can have one, two, or three phosphate groups attached to it. ATP has an adenosine backbone, which is a combination of adenine (the nitrogenous base) and ribose (the five-carbon sugar), plus three phosphate groups (α, β, and γ) attached.
A genetic study conducted over two generations found that the frequencies of genotypes in the first generation were AA: 0.36, Aa: 0.48, and aa: 0.16. In the second generation, genotype frequencies remained the same. According to the Hardy-Weinberg equilibrium, we can assume:_______.
Answer:
We can assume that there are no evolutionary changes.
Explanation:
The Hardy-Weinberg Equilibrium is a law which suggests that if the allele frequencies or genotype frequencies do not change in between different generations, then there is no evolutionary influence on that species.
In the example given in the question, it is stated that the genotype frequencies stay the same for the second generation, so according to Hardy-Weinberg equilibrium we can assume that there are no evolutionary changes.
I hope this answer helps.
Answer:
mating in this population is random
Explanation:
In very simple terms, population genetics involves analyses of
the interactions between predictable, "deterministic"
evolutionary forces and unpredictable, random, "stochastic"
forces. The deterministic forces are often referred to as
"linear pressures" because they tend to push allele frequencies
in one direction (up, down or towards the middle).
The Hardy–Weinberg principle states that allele and genotype
frequencies in a population will remain constant from generation to
generation in the absence of other evolutionary influences. These
influences include genetic drift , mate choice , assortative mating ,
natural selection , sexual selection , mutation , gene flow , meiotic
drive , genetic hitchhiking, population bottleneck , founder effect and
inbreeding .
In the simplest case of a single locus with two alleles denoted A
and a with frequencies f (A) = p and f (a) = q , respectively, the
expected genotype frequencies under random mating are f (AA) = p 2
for the AA homozygotes , f (aa) = q 2 for the aa homozygotes, and f
(Aa) = 2 pq for the heterozygotes . In the absence of selection,
mutation, genetic drift, or other forces, allele frequencies p and q are
constant between generations, so equilibrium is reached.
Suppose that the human insulin protein that was produced by the bacteria was much shorter than it should be. Upon further investigation, it was found that the DNA of the human insulin gene had a mutation while in the bacterial cells. What type of mutation could not result in these observations?
Explanation:
Mutations are changes in a DNA sequence, and they can occur due to radiation or other types of DNA damage. If mutations occur in the part of a gene that encodes a protein (the coding region of a gene), they can change the amino acid sequence of that proteinBut not always; a silent mutation is a type of mutation in the coding region of a gene that doesn't actually change the amino acid sequence of the protein that is madeA point mutation is a change in one nucleotide or base pair of a DNA sequence. An example would be if a C in the DNA code was changed to a T Point mutations can happen anywhere along a DNA sequence, Mutations in the coding region of DNA can directly affect the amino acid sequence of the protein productA human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water.If ADH secretion is inhibited, which of the following would initially result?
a) Number of aquaporins would increase in response to the inhibition of ADH
b) The person would decrease oral water intake to compensate for the inhibition of ADH
c) Blood filtration would increase to compensate for lack of aquaporins
d) Person would produce a greater amount of dilute urine
Answer:
d) Person would produce a greater amount of dilute urine
Explanation:
ADH stands for anti diuretic hormone. It is also called vasopressin or arginine vasopressin. It is a hormone produced by the hypothalamus of the brain and then stored in the posterior pituitary gland.
Anti diuretic hormone acts by regulating the water balance in the blood. Osmotic sensors in the hypothalamus react to the concentration of particles in the blood. These particles include molecules of sodium, potassium, chloride, etc.
When blood pressure is too low, these sensors and baroreceptors tell your kidneys to release water to maintain a healthy range of these substances. They also regulate the body’s sense of thirst.
The majority of the benefits of exercise during pregnancy occur in the ____________; the majority of the risks of exercise during pregnancy apply to the ___________.
Answer: mother, fetus
Explanation:
There are many benefits associated with exercise to the mother this includes the reduction in back pain, it helps in constipation, promotes healthy weight, improves the fitness of mother and strengthen the heart and also improves the blood vessels by preventing the deposition of fat in them.
There are majority of risks associated with the fetus during pregnancy these includes the premature contraction of the uterus, premature labor and premature birth of the fetus. The overexercise done by mother is likely to affect the growth of the fetus.
In viruses called retroviruses, the genetic information is contained in RNA; these viruses have no DNA. These viruses also have an enzyme called reverse transcriptase. What is its function?
Answer:
It catalyses the synthesis of complementary DNA copies from RNA.
Explanation:
The reverse transcriptase is an enzyme that allows strands of DNA molecules to be synthesized from a single strand RNA template. The enzyme, also known as RNA directed DNA polymerase is usually used by retroviruses to synthesize complementary DNA sequence from an RNA template, a process that is an opposite of transcription.
In retroviruses, the enzyme reverse transcriptase's main function is to convert the virus's RNA back into DNA, which can then be integrated into the host cell's genome, allowing the virus to replicate. This unique mechanism has led to the development of specific drugs that can inhibit these enzymes and prevent viral replication.
Explanation:In retroviruses, such as HIV, the genetic information is stored in RNA instead of DNA. These retroviruses encode an enzyme known as reverse transcriptase. The principal function of reverse transcriptase is to convert RNA back into DNA which is then incorporated into the genome of the host cell. This process, also referred to as reverse transcription, allows the virus to replicate using the host's cell machinery, effectively using its cells as a factory to produce more viruses. This is unique to retroviruses, because in healthy, uninfected cells, this transcription process usually travels from DNA to RNA, not the other way around.
Interestingly, this unique mechanism has facilitated the development of drugs to inhibit reverse transcriptase and stop the virus from replicating without disrupting the host's normal cellular functions. Some of these drugs include reverse transcriptase inhibitors like AZT used in the treatment of HIV. This strategic approach has resulted in significant progress in managing and controlling diseases caused by retroviruses.
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The cichlid Cynotilapia afra, introduced at West Thumbi Island in Lake Malawi in the 1960s, has split into two genetically distinct populations, located at the north and south ends of the island. How can scientists determine whether these populations are now different species, according to the biological species concept?
Answer:
Determine whether individuals from one population will interbreed with individuals from the other population when introduced into each other's native habitats
Explanation:
According to the biological species concept, organisms can be considered to be of the same species if they can interbreed successfully together to produce a viable and fertile offspring.
Therefore, to determine whether these populations are now different according to the biological species concept, scientists should introduce both individuals from each population to each other. If they are able to interbreed and produce viable and fertile offspring, it means they are of the same species, but if they are unable, it means they are not of the same species.
Final answer:
Scientists can determine whether the populations of Cynotilapia afra on West Thumbi Island are different species by studying their reproductive isolation and genetic differences.
Explanation:
According to the biological species concept, two populations are considered different species if they are reproductively isolated and cannot produce viable offspring. To determine if the populations of Cynotilapia afra on West Thumbi Island are different species, scientists can study their reproductive isolation and genetic differences. They can analyze the mating behavior and breeding success of individuals from the north and south populations to see if they are interbreeding. Additionally, they can examine the genetic makeup of individuals from both populations to determine if there are significant genetic differences. If there is evidence of reproductive isolation and genetic differentiation, it would suggest that the north and south populations of Cynotilapia afra on West Thumbi Island have diverged enough to be considered different species.
What feature distinguishes this type of capillary from a continuous capillary?
Explanation:
Fenestrated capillaries are "leakier" than ceaseless vessels. They contain little pores, notwithstanding little holes between cells, in their dividers that take into consideration the trading of bigger particles. This sort of narrow is found in territories that require a great deal of trade between your blood and tissues.Function-
Capillaries are exceptionally minor veins so little that a solitary red platelet can scarcely fit through them. They help to interface your courses and veins in addition to facilitating the trading of specific components between your blood and tissues. This is the reason tissues that are extremely dynamic, for example, your muscles, liver, and kidneys, have a wealth of vessels. Less metabolically dynamic tissues, for example, specific sorts of connective tissue.This is the study of similar and different structures in organisms.
Answer:
comparative anatomy
Explanation:
comparative anatomy is the study of similarities and differences in the structure/anatomy of different species. it has aided in the study of evolutionary biology and of common descent.
Final answer:
Comparative anatomy is the study of the similarities and differences in the structures of different species. Evidence for evolution is provided by homologous structures.
Explanation:
Comparative anatomy is the study of the similarities and differences in the structures of different species. Scientists compare the anatomy, embryos, and DNA of living things to understand how they evolved. Evidence for evolution is provided by homologous structures, which are structures shared by related organisms that were inherited from a common ancestor.
A bear is placed in a laboratory whose interior is designed to precisely mimic its natural environment. However, the environment is kept in full light 24 hours a day, 365 days a year. Which of the following is the bear likely to do?1) attempt to mate.
2) behave normally.
3) stop foraging.
4) fail to hibernate.
Answer:
4) fail to hibernate
Explanation:
Animals, such as bear, tend to hibernate when the conditions of the environment become harsh for them. As a result, the go to hibernation mode for that period of time. Bears usually hibernate during the winter season when the temperature outside becomes lower.
When a bear will be placed in the laboratory with constant sunlight, the bear will fail to hibernate as the bear will have no burrow or cave for hibernation and also he might consider the light source as conditions being warm.
When the level of arterial carbon dioxide rises above normal: Select one: a. exhalation lasts longer than inhalation. b. the brain stem inhibits respirations. c. respirations increase in rate and depth. d. respirations decrease in rate and depth.
Explanation:
The term Hypercapnia or Hypercarbia is given to the body's response to excessive carbon dioxide. At the point when [tex]CO_2[/tex] levels become unnecessary, a condition known as Acidosis happens.Respiration is the biochemical process where organism's cell obtain energy when glucose and oxygen combine, and that result in the production of carbon dioxide, water and ATP.When arterial carbon dioxide level rises above normal, respirations increase in rate and depth due to the stimulation of the respiratory centers in the brain. These centers control the respiratory rate and depth based on chemical and pH changes in the blood.
Explanation:When the level of arterial carbon dioxide rises above normal, respirations increase in rate and depth. This is because a rise in carbon dioxide or a decline in oxygen levels in the blood stimulates an increase in respiratory rate and depth. The respiratory centers of the brain, stimulated by chemical and pH changes in the blood, control respiratory rate and depth.
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