Answer:
The correct answer will be- this base pairing allows the complementation like lock and key
Explanation:
In DNA, the nitrogenous bases on one strand pairs with the nitrogenous bases on another strand.
Experiments of Erwin Chargaff showed that purine bind pyrimidines where the adenine binds thymine and guanine bind cytosine via double and triple hydrogen bonds respectively.
This hydrogen bonding between the purines and pyrimidines provides structural stability as it is based on the complementation. This complementary base pairing allows the two strands to fit like a key and a lock.
Thus, this base pairing allows the complementation like lock and key is the correct answer.
Consider the food chain of grass → grasshopper → mouse → snake hawk. About how much of the chemical energy fixed by photosynthesis of the grass (100 percent) is available to the hawk? .
A) 0.01%
B) 0.1%
C) 1% .
D) 1090
What is the main function of the ozone layer? a. to provide cloud cover for protection of polar regions b. to block most of the sun's damaging rays from reaching Earth c. to filter toxins from acid rain d. to trap carbon dioxide and warm the planet e. to provide a source of oxygen for photosynthesis
Answer:
The main function of the ozone layer is to block most of the sun's damaging rays from reaching Earth.
Option: (b)
Explanation:
The stratosphere containing high level of ozone molecules about 30 km to 50 km altitude helps to absorb the sun's ultra violate rays. In its absence, it would be very difficult for anything to survive. Plants cannot live and grow as the UV light causes weakening of plants. It causes skin cancers. The increase in UV flux will lead to increase in sunburn, blindness, cataract, causing potentially death of animals and plants.Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?A) a temporal reproductive isolating mechanism.B) a behavioral reproductive isolating mechanism.C) a gametic reproductive isolating mechanism.
Answer:
The correct answer will be option-B
Explanation:
A species is a group of similar organisms which interbreed with the individual of the same group of closely related individuals.
Species are reproductively isolated by various mechanisms, one of which is due to the behavior.
When the species are not able to reproduce to different species due to the differences in their behaviour in terms of mating rituals which could be due to different mating rituals or a different way of mating like observed in the grasshoppers is known as behavioral reproductive isolating mechanism.
In grasshoppers, the grasshopper's species cannot interbreed due to the differences in the mating songs as a part of the behavior.
Thus, Option-B is the correct answer.
Final answer:
Different courtship songs in cricket populations act as a behavioral reproductive isolating mechanism, facilitating mate recognition and preventing interbreeding between different populations.
Explanation:
If three populations of crickets have males with different courtship songs, the variation in song would likely serve as a behavioral reproductive isolating mechanism if the populations came into contact. This behavioral distinction leads to mate recognition, where females respond only to the songs of males of their own population, thereby ensuring that mating occurs only within the same species or population. The song acts as a signal that is recognized by potential mates, which is crucial for maintaining species integrity and avoiding hybridization.
Courtship behaviors like the cricket's song play a critical role in species recognition. They allow individuals to identify and select appropriate mates from their own species. Another example of this is the use of specific light patterns by different species of fireflies to attract mates; females will only recognize and respond to the light pattern specific to their own species. This is a clear demonstration of behavioral reproductive isolation, where the presence or absence of a particular behavior prevents interbreeding and helps in maintaining species-specific characteristics.
To enter the citric acid cycle, pyruvate must enter the mitochondria by active transport. Three things are necessary to convert pyruvate to acetyl CoA. Explain the three steps in the conversion process.
Answer:Decarboxylation, the Reduction of NAD+, and the attachment of CoA.
Explanation:
Step 1 Decarboxylation: the co-enzyme thiamine pyrophosphate (TPP) catalyzes the decarboxylation of the carboxyl group of pyruvate and given off as a molecule of CO2. The two carbon unit remains attached to the enzyme.
Step 2 Reduction: The remaining two-carbon (hydroxyethyl group) is oxidized to form acetyl group. The extracted electrons are transferred to NAD+, storing energy in the form of NADH.
Step 3. The last step is the attachment of coenzyme A, a sulfur compound derived from a B vitamin, is attached to the acetyl group to form acetyl CoA, the Co-enzymes TPP, Lipoamide and FAD will be regenerated.
The acetyl CoA will go into TCA for complete oxidation.
David sustained a complete avulsion of his hamstring tendons from their origin on the ischial tuberosity. Hamstrings are part of what class of lever at the knee?
a) The hamstrings are part of a first-class lever, where the fulcrum is between the applied force and the load.
b) The hamstrings are part of a second-class lever, where the load is between the applied force and the fulcrum.
c) The hamstrings are not part of the lever system.
d) The hamstrings are part of a third-class lever, where the applied force is between the load and the fulcrum.
Answer:
The answer is letter D.
Explanation:
The hamstrings are part of a third-class lever, where the applied force is between the load and the fulcrum.
A graph titled "Average hamster weight (kg) vs. Amount of drug (mg/day)"
shows a downward-sloping line that reaches a minimum value and then stays there over the remainder of the graph.
what noticeable trend from this graph might be used to make a conclusion?
A. average hamster weight is not affected by the daily amount of a drug.
B. average hamster weight causes the amount of drug to increase daily.
C. average hamster weight doubles every time the daily amount of a drug is doubled until all of the drug has been used up.
D. average hamster weight decreases with an increase in the daily amount of a drug until the hamsters reach a minimum possible weight.
Explanation:
D. average hamster weight decreases with an increase in the daily amount of a drug until the hamsters reach a minimum possible weight.
Trend: There was a gradual decrease in the hamster's weight til a minimum was reached, after with the rate of its change in weight with treatment over time plateaued.
Trends are gradual notable changes or patterns over a series of data points on a line or curve of a graph. These allow for summarizing data and predicting results. A data summary provides a comprehensive report of experimental findings. This makes the analysis of data easier by answering key research objectives outlined in the experimental procedure. Summaries allow for tracking trends and procedural changes, observations and potential; this makes it easier to arrive at conclusions faster.
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Answer:
the answer is D
Explanation:
just took it
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information. Which of the following characteristics of DNA is responsible for this?:
a. sequence of bases
b. sugar-phosphate backbones
c. complimentary base pairs
d. side groups
e. 5-carbon sugars
Answer: a. Sequence of bases
Explanation:
James Watson and Francis Crick, discovered the famous double helix structure or spiral staircase, found in DNA.
DNA is a molecule composed of a sugar-phosphate backbone, which consists of 5-carbon deoxyribose sugars and phosphate groups. The monomers of DNA are called nucleotides, and each one contains a phosphate group, a sugar group and a base. A sequence of bases is a succession of letters representing the primary structure of DNA with the ability to carry information. The letters are A, C, G, and T, which symbolize the four nucleotide subunits of a DNA (adenine, cytosine, guanine, thymine) And there is a complementary base pairing which is the phenomenon where guanine always bonds to cytosine, and adenine always binds to thymine.
The sequence of bases in DNA determines the sequence of amino acids in a particular protein, which will have a specific structure and function.
Water particles adhere tightly to soil particles due to _____. a. adhesive properties of minerals in the soil b. hydrogen bonding with negative charges on soil particles c. the small spaces between particles through which gravity can draw the water d. ionic bonding with negative charges on soil particles e. hydrogen bonding with positive charges on soil particles
A
Water in the soil is held tightly by adhesive forces between the water molecules and the mineral content in soil particles - in the microspores.
Explanation:
While water passes through the macrospores of soil by gravity, water passes through the microspores mainly by cohesion between the water molecules and adhesion between the water molecules and soil minerals. The more surface area for the minerals in the soil (due to finer particle sizes) the higher the water retention rate of the soil. This is why soil with more humus (like silt and clay) retains water more than soils like sand.
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Which group of air pollutants tend to cool the atmosphere because they reflect more sunlight back to space thus reducing incoming solar radiation? A. CFCs. B. ozone enhancers. C. nitrous oxides. D. atmospheric aerosols.
Answer:
D. atmospheric aerosols.
Explanation:
Atmospheric aerosols are tiny particles that float in the air. These particles could be liquid or solid and are usually suspended primarily by direct emission into the atmosphere or secondarily by condensation process.
Atmospheric aerosols have numerous effects on the biotic and abiotic factors of the environment. They alter air quality and impact human health in some cases, they can reduce atmospheric visibility, and they also reduce the amount of radiation that reaches the earth by scattering or reflecting some of the radiations from the sun back into space, leading to cooling of the atmosphere.
During which phase of mitosis do chromosomes line up at the spindle equator?
Chromosomes line up at the spindle equator, or metaphase plate, during the metaphase phase of mitosis. This alignment is crucial for even chromatid distribution during cell division.
Explanation:During the mitosis phase known as metaphase, chromosomes, which consist of sister chromatids, align at the spindle equator, also referred to as the metaphase plate or the equatorial plane. This alignment ensures that when the cell divides during anaphase, the sister chromatids will separate evenly and be distributed to the two daughter cells. The attachment of spindle fibers to the centromeres of each pair of sister chromatids is integral to this process.
In anterograde amnesia ______. a. there is an inhibition of afferent inputs to the cerebral cortex b. LTM (long term memory) is not disrupted c. communication between the medial temporal lobe and the association cortex remains unaffected d. declarative memory is not significantly altered
Answer:
The correct option is b. LTM (long term memory) is not disrupted.
Explanation:
Amnesia is a type of disorder that affects our memory, we talk about anterograde amnesia when it involves a serious damage/lost in our short-term memory (the long term memory is not disrupted), that is, it is the inability to create new memories. This selective memory deficit is caused by a brain lesion located in the hippocampus and in the areas of the medial temporal lobe. The hippocampus has the function of generating new memories, if it is affected, then it will be impossible to establish the memories.
Anterograde amnesia is the inability to form new memories after a brain trauma. It does not disrupt long-term memory, but it hampers the transfer of information from short-term to long-term memory. Declarative memory is primarily affected, while procedural memory remains intact.
Explanation:Anterograde amnesia refers to the inability to form new memories from a particular time forward. It is commonly caused by brain trauma, which affects the hippocampus. With anterograde amnesia, long-term memory (LTM) is not disrupted, but there is a loss of memory for events that occur after the brain trauma.
In anterograde amnesia, communication between the medial temporal lobe (where the hippocampus is located) and the association cortex remains unaffected. However, there is an inhibition of afferent inputs to the cerebral cortex, which hampers the transfer of information from short-term to long-term memory.
While anterograde amnesia primarily affects declarative memory (the conscious memory of facts and events), it does not significantly alter procedural memory, which involves skills and habits.
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Lyme disease is caused by a bacterium transmitted to people by deer ticks. Deer ticks are almost never born infected with the bacterium, but they can pick it up from feeding on an infected host in any of the tick's three successive stage of development: larva, nymph, adult. Once infected, a tick remains infected through any subsequent developmental stages, but since a tick feeds on only one host in each stage, it follows that ______________
A. People can be infected only by being bitten by a tick that is either in larval stage or in the nymph stage
B. People cannot be infected by a tick that picked up the Lyme disease bacterium in the adult stage
C. It is not possible for a person to be infected by a tick that is in the nymph stage or by a tick that was infected with the bacterium while in the nymph stage
D. People infected with the Lyme disease bacterium cannot transmit bacterium to adult deer ticks
E. Only deer ticks that are adults can transmit the Lyme disease bacterium to people
Answer:
Option B
Explanation:
Tick that contract the bacterium in the adult stage from its host then will not be able to infect humans as it will stay will that infected host for its adult phase and subsequently die as there are no other developmental phases.
Which of the following variations on translation would be most disadvantageous for a cell?A) translating polypeptides directly from DNA.B) using fewer kinds of tRNA.C) having only one stop codon.D) lengthening the half-life of mRNA.E) having a second codon (besides AUG) as a start codon.
Answer:
The correct answer is A) translating polypeptides directly from DNA.
Explanation:
Transcription process is important for the production of proteins because mRNA is synthesized during the transcription process which has the correct sequence of codon which is read by ribosomes to make proteins.
DNA does not contain the right codon sequence for the formation of proteins and does not have uracil nucleotide which is found in mRNA therefore if DNA is used for translation then the wrong amino acids will be added into the polypeptide chain which can generate non-functioning proteins or mutated protein.
Therefore translating polypeptide directly from DNA would be more disadvantageous to the cell.
A penetrating stab wound to the heart wall that causes blood to leak into the pericardial cavity would result in A penetrating stab wound to the heart wall that causes blood to leak into the pericardial cavity would result in hypertrophic cardiomyopathy. endocarditis. cardiac tamponade. myocardial infarction.
Answer:
The correct answer is cardiac tamponade.
Explanation:
Cardiac tamponade is the cause of the pericardial space being filled with liquid. This syndrome occurs in emergencies, as is the example of a stab penetrating wound and if it is not treated urgently it can result in pulmonary edema, shock and even death.
What happens in this case is that the pericardium receives a high pressure which causes that the pumping of blood it is not carried out correctly, and the heart is compressed decreasing the filling during diastole.
The most appropriate procedure to treat this type of emergency is a pericardiocentesis that allows studying and draining the fluid lodged in the pericardium so that the pressure can decrease.
Research has indicated that during the inflammatory response to P. acnes, both the classical and the alternative complement pathways are activated. Which of the following are outcomes of activating complement pathways?
Select all that apply.
A. activation of T cytotoxic cells
B. inflammation
C. generation of antibodies against P. acnes
D. opsonization
E. cytolysis
Answer:
The correct answers are options B, D and E.
Explanation:
One of the essential parts of the innate immune system is the complement system. This system performs an essential function in elevating the tendency of antibodies and phagocytic cells to eliminate the pathogens. There are three biochemical pathways, which instigate the complement system that comprises the classical, alternative, and lectin complement pathway.
The fundamental activities of the complement system are opsonization, cell lysis, chemotaxis, and agglutination. The process of cytolysis takes place through the complement pathway by the generation of membrane attack complex in the raiding cells. The complement pathway also leads to inflammation.
Every day your epidermis normally sheds dead skin cells. What is the first step in the process by which epidermal cells are replaced?
Final answer:
The first step in the replacement of epidermal cells involves cell division in the stratum basale layer of the epidermis. New keratinocytes form and ascend through the epidermis, becoming part of the protective stratum corneum before they are shed.
Explanation:
The first step in the process by which epidermal cells are replaced begins with the innermost layer of the epidermis, the stratum basale (or stratum germinativum). In this layer, cells continuously divide through mitosis to form new keratinocytes. These newly formed cells then start their journey upwards through the multiple layers of the epidermis, producing more of the protein keratin as they move.
As the new keratinocytes accumulate keratin, they undergo a process of cell death (apoptosis), and eventually integrate into the stratum corneum, the outermost layer, becoming the flat, dead skin cells that we see and that are ultimately shed. This cyclical process of cell renewal and shedding helps keep our skin's barrier function intact. The whole turnaround, from cell birth to shedding, takes about 4 weeks in a healthy adult.
The specialized membranes that surround the spinal cord are termed the
Answer: Spinal Meninges
Explanation:
Answer is spinal meninges
Spinal meninges are specialize membranes that surrounds the spinal cord and the brain. Spinal meninges consist of three membrane layers that surround the spinal cord. The three membrane layers are dura mater, arachnoid mater, and pia mater.
Dura mater: The outermost and the thickest membrane.
Arachnoid mater is the middle layer which connects the dura mater and the pia mater.
Pia mater is the innermost layer, it forms a coat around the spinal cord and brain.
Also cerebrospinal fluid (CSF) are liquid that circulate the Spinal Meninges.
Give an example of how the rock cycle can change one type of rock into another
The three main rock types are igneous, metamorphic and sedimentary. The three processes that change one rock to another are crystallization, metamorphism, and erosion and sedimentation. Any rock can transform into any other rock by passing through one or more of these processes. This creates the rock cycle
Answer: in the picture
Explanation:
Ah! I smell cookies baking! I cannot wait to taste them: warm and sweet! Smell and taste are closely related senses. Identify the one statement that does not describe these two senses. A) If an organism does not have a receptor for a particular odor molecule, for that organism, the odor has no smell. B) Both smell and taste use chemoreceptors, which means they are both sensing the chemical environment. C) If one’s sense of smell is not functional, then the sense of taste will also not function. D) The senses of smell and taste combine at the back of the nasal passage
Answer:The answer to this question is D: The senses of smell and taste combine at the back of the nasal passage.
Mendel discovered that the allele for green seed pods (G) is dominant to the allele for yellow seed pods (g). He crossed true-breeding (homozygous) parental plants with green (GG) and yellow (gg) seed pods to produce an F1 generation, all of which were heterozygous (Gg) with green seed pods. He then crossed two of these F1 plants to produce an F2 generation.
Drag the genotypes and phenotypes from the left to correctly complete the Punnett square for the F2 generation. Drag only blue labels to blue targets and pink labels to pink targets. Labels may be used more than once.
Answer:
GG, Gg, Gg, gg
Homozygous green – GG
Heterozygous green – Gg
Homozygous yellow - gg
Explanation:
It is given that allele for green seed pods (G) is dominant to the allele for yellow seed pods (g) which means that if “G” and “g” occur together, a trait associated with G will be expressed.
The genotype of the true breeding Green plant is “GG”
The genotype of the true-breeding yellow plant is “gg”
F1 generation cross
GG * gg
Offspring produced from F1 generation are – Gg, Gg, Gg, Gg
In f2 generation offspring of F1 generation are crossed among each other.
So the offspring produced in F2 generation are
Gg * Gg
GG, Gg, Gg, gg
Homozygous green – GG
Heterozygous green – Gg
Homozygous yellow - gg
Classify a fiber tract that communicates between the left prefrontal lobe and the left parietal lobe.
Answer:
The answer is association fibers
Explanation:
Association fibers communicate between gyri in the same cerebral hemisphere.
The gyri is a ridge tissue on the surface of the cerebral hemisphere.
Which cranial nerve carries visual information from the eyeball to the brain?
Answer: Optic Nerve
Explanation: The optic nerve also called cranial nerve II. It is the connector btw the eye and brain. It is the nerve that carries visual images from the eyes to the brain.
There is a nerve called the retina. The visual message is sent through the retina to the brain.
The optic nerve carries visual information from the eyeball to the brain.
Explanation:The cranial nerve that carries visual information from the eyeball to the brain is the Optic Nerve (Cranial Nerve II). It is responsible for transmitting visual signals from the retina to the visual processing centers in the brain, primarily to the occipital lobe. The optic nerve consists of over a million nerve fibers that combine to form a thick bundle that exits the back of each eye and then converge at the optic chiasm, where some fibers cross over to the opposite side of the brain, while others remain on the same side.
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Why would the cells of the palisades layer have more chloroplasts in them
Answer:
Because they re located in the leaves, the part of the plan with wider area to receive the sunlight
Explanation:
Palisade cells are the plant cells that contain the largest amount of chloroplast per cell, this is convenient because they can be found on leaves, the portion of the plant with a wider superficial area, this means that a larger number of chloroplasts will receive the sunlight and therefore this will benefit the photosynthesis process.
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A physician orders a general health panel, all tests except a creatinine, including cbc with automated differential. what cpt® code(s) is/are reported?
Answer:
The answers are 85025, 84443, 82040, 82247, 82310, 82374, 82435, 82947, 84075, 84132, 84155, 84295, 84460, 84450, 84520.
Explanation:
The panel codes cannot be reported unless the physcian species exactly which tests were performed in the patient. If any test is left out, this test will need to be coded individually.
Charles Darwin developed the theory that explains how new species develop based on evidence from many different kinds of scientific inquiry. Darwin’s theory can only be accurate if the earth is very old. The scientists who provided evidence for the earth’s old age were most likely: a) astronomers such as Edwin Hubble. b) geologists such as James Hutton. c) biologists such as Francis Crick. d) physicists such as Marie Curie.
Answer:
The correct option is b) geologists such as James Hutton
Explanation:
Charles Darwin brought forward the theory that new species developed from older species. The species which were better adapted to live in an environment survived and passed on their traits to the offsprings.
As evolution took long periods of time hence, for evolution to occur the Earth must be very old. Geologist such as James Hutton worked out to find the history of the Earth and James Hutton believed that processes such as sedimentation and erosion could be used to diagnose the history of the Earth.
Answer:
b
Explanation:
Cellulose and glycogen are both homopolymers of glucose units. Humans cannot digest cellulose but can break down glycogen into individual glucose units. Which type of enzyme is lacking in humans that would allow them to break down cellulose? Hint: Look at the name of the enzyme to see the type of bond they are involved in breaking down through catalysis.
Answer:
the lacking in human is called Cellulase which is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis and bring about the decomposition of cellulose and of some related polysaccharides.
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?
A) mucociliary escalator
B) normal skin flora
C) phagocytosis in the inflammatory response
D) acidic skin secretions
E) lysozyme
Answer:
The correct answer is option C) phagocytosis in the inflammatory response.
Explanation:
Our body has an immune response mechanism for when we get hurt or when it feels that something outside our body wants to harm us, so its automatic reaction is to defend against all those bacteria and viruses that want to attack us.
The system is responsible for identifying the antigens and destroying them. The antigens are all bacteria, harmful viruses and dead substances that are found on the cells. Our system has its own proteins that are HLA antigens. But as these are normal for the body, it does not counterattack them.
There are several defense mechanisms that work as barriers to prohibit the passage of any bacteria that harm us, and one of these mechanisms is inflammation.
In this case, when our body suffers some kind of injury from a bacterium, a cut or a blow, the damaged cells release substances that spill onto the tissue through the blood vessels, causing inflammation.
This allows the foreign substance to be “locked up” and cannot enter the body.
These spilled substances also attract white blood cells, which are called phagocytes which are responsible for eating dead germs and cells through the phagocytosis process.
Upon his visit to Uganda, Churchill described the landscape as a "beautiful garden of death" because so many individuals were chronically infected with African Sleeping Sickness. What is the causative agent of this disease and its corresponding vector?
Answer:
It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. It is a vector-borne parasitic disease transmited by the Tse-tse fly.
Explanation:
African sleeping sickness, named human African trypanosomiasis, is a vector-borne parasitic disease transmited by the Tse-tse fly (that belongs to the Glossina genus). These flies can acquire the parasite by biting infected humans or animals.
The causative agent is a protozoan of the genus Trypanosoma,
It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. It can be Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense. Trypanosoma brucei gambiense has a prevalence of 98% of the reported cases, while Trypanosoma brucei gambiense accounts for the 2%.
Preparation for the "rest and digest" response includes activation of the ________ nervous system. Preparation for the "rest and digest" response includes activation of the ________ nervous system. parasympathetic sensory sympathetic somatic]
Answer:
parasympathetic
Explanation:
The parasympathetic nervous system is the part of the autonomic division and is responsible for rest and digest response during rest and recovery time. The parasympathetic nervous system serves to restore and conserve energy. The parasympathetic division is also called housekeeper division since it promotes all the internal responses associated with a relaxed body state. It causes the contraction of the pupil of the eye, promotes digestion and absorption of food, and slows down the heartbeat and other body functions that support the physical activity.
Recall that Zajonc placed cockroaches either in a complex maze or a simple maze. He created three other conditions as well. Any given cockroach was induced to navigate the maze (a) entirely alone, (b) in the presence of an "audience" of cockroaches, or (c) simultaneously with another cockroach (but without an audience). The audience condition (b) permitted Zajonc to demonstrate whether:
a. audiences pay attention to competitors.
b. the mere presence of others can facilitate or hinder performance.
c. complex tasks are performed less well than simple tasks.
d. competitive situations are preferred over solitary situations.
Answer:
The audience condition permitted Zajonc to demonstrate whether the mere presence of others can facilitate or hinder performance.
Option: (b)
Explanation:
R. B. Zajonc presented a "theory of social facilitation". He organized an experiment with the cockroaches to find if there was any noticeable change in the mean number of dominant responses acted between the participants in the audience condition and the one in the solitude environment. It was found that there was difference which proves the social facilitation theory, that the presence of audience can hinder the performance.