Answer:
Group VI viruses (retroviruses)
Explanation:
Baltimore classified the viruses in different groups on the basis of their mode of replication and the type of genetic material they possess.
In the given question, the species which contains an ssRNA molecule but use DNA as an intermediate molecule to replicate is known as a retrovirus.
The retrovirus uses a special enzyme called reverse transcriptase which synthesizes the DNA from an RNA template. The DNA formed gets integrated into the host genome and gets replicated.
Thus, Group VI viruses are the correct answer.
The ___________ is an important element of the drug experience because it affects how much of a drug reaches its site of action and how quickly it gets there.
Answer:
Route of administration
Explanation:
Drugs may be defined as the chemicals that are given against the particular disease for the treatment of the patient. The drugs must be given in the proper amount as directed by the medical practitioner.
The effects of the drugs depend on the individual and its route of administration. The oral administration of drug is more common but a diabetic patient needs to given drug intravenously. Intraperitoneal drug route is given to show the effect of drug quickly and drug cannot infiltrate a blood vessel.
Thus, the answer is route of administration.
He is best known for developing a method to classify plants and animals and established the system of binomial nomenclature. A. Charles Darwin B. Carolus Linnaeus C. Jean-Baptiste Lamarck D. Georges Cuvier
Answer: Option B) Carolus Linnaeus
Explanation:
The linnaean system of classification was introduced by a Swiss scientist named Carolus Linnaeus.
In this system, he first split living things into a general category called KINGDOM.
- The kingdom is further split into large smaller groups called PHYLUM (for animals) and DIVISION (for plants).
- Each phylum or division is broken down into CLASSES.
- Each class is broken down into ORDERS
- Orders into FAMILIES,
- Families into GENUS
- Genus into SPECIES
Also, he introduced the system of binomial nomenclature where an organism is described by two names:
- the 1st name is genus;
- the 2nd name is species.
For instance: Homo sapiens would means Man belongs to genus (Homo) and specie (sapiens).
Hence, binomial nomenclature consists of two names
Answer:
b
Explanation:
Sumer has come up with a great analogy for a presentation she is giving in her psychology class. The membrane encasing a neuron only allows some ions to pass in and out of its channels. And she is going to describe this _____ membrane as a guard only allowing some patrons to enter and leave a controlled area.
Answer:
Cell membrane
Explanation:
Sumer has come up with a great analogy for a presentation she is giving in her psychology class. The membrane encasing a neuron only allows some ions to pass in and out of its channels. And she is going to describe this cell membrane as a guard only allowing some patrons to enter and leave a controlled area.
Answer:
Cell surface membrane.(Axolemma)
Explanation:
These membranes encasing the neuron is perforated by ion channels, which allow diffusion of ions with their charges across it down their electrochemical gradients. These ion channels are specific to a particular ion, while restricting others. E,g sodium-potassium pump , are special ion channels in axon cell membrane with specif channels for sodium ions, and will not allow the passage of potassium through the same channels and vice-versa.
There are two types on these ion channels based on what controls their openings.
The voltage gated ion channels which are controlled by the electrical potential or voltage generated across the axon.And the ion channels control by the electrochemical gradients of the ions moving across the membrane.
The reversal of the charges of these ions across it (axonlemma) create membrane potential down the length of the membrane. This set up a voltage change inside the Axoplasm(cytoplasm of the axon). If this voltage is up to the threshold it creates depolarization of the ( ion channels)with influx of sodium ions, while the potassium ions channels are shut up.
Furthermore, if the stimulation of the neuron is intense, and the membrane potential increases up to the threshold level the electrical potential energy generated cause the (voltage gated channels to open) . The potential generated is called Action potential.
Summary
The specificity of these channels to certain ions while restricting others is a good illustration for Sumer to describe how a guard can control the movement of patrons in a controlled area.
In exploring for coal deposits, geologists sometimes look for fossil indicators: fossilized remains of Carboniferous plants. Which of the following combinations in a sample would suggest the presence of rocks that might bear coal beds?
1. mosses and liverworts, but no vascular plants
2. angiosperms and mosses
3. lycophytes and gymnosperms
4. lycophytes and tree ferns
Answer:
During the carboniferous there is a proliferation of plants such as lycopodia and ferns. Theirs remains have generated large carbon deposits worldwide. These experimental plants reach their maximum richness and diversity during the Carboniferous (300-350 million years).
Dieffenbachia plants usually grow well without fertilizer. A student wanted to see if adding liquid fertilizer would make a difference in the growth of the plant. Three plants were placed in the same type of pot with the same type of soil. Two plants received fertilizer and one plant did not. All plants received the same amount of light and water during the experiment.She watched the plants grow over a period of 30 days, only adding the same amount of water to each plant on a weekly basis.
Answer:
amount of Liquid fertilizer
Explanation:
Complete Question
Dieffenbachia plants usually grow well without fertilizer. A student wanted to see if adding liquid fertilizer would make a difference in the growth of the plant. Three plants were placed in the same type of pot with the same type of soil. Two plants received fertilizer and one plant did not. All plants received the same amount of light and water during the experiment.She watched the plants grow over a period of 30 days, only adding the same amount of water to each plant on a weekly basis. What variable is NOT being controlled in this experiment?
Solution
In an experiment the variables are categorized into two groups
a) Controlled and
b) Uncontrolled
Uncontrolled variable are the ones which are independent i.e any kind of variation in experiment or any of its factor does not impact the uncontrolled variable. Such variable when in itself are varied, affect all other controlled variable.
Thus, amount of liquid fertilizer is an uncontrolled variable while factors such as growth of plant etc. are controlled variable.
The student conducted a 30-day experiment comparing Dieffenbachia plant growth with and without liquid fertilizer under consistent light and water conditions.
The controlled variables included the amount of light, water, and frequency of watering provided to all plants.
This ensures that these factors did not influence the results, as all plants experienced the same conditions.
Light is crucial for photosynthesis, and water is essential for plant hydration and nutrient uptake.
The dependent variable was the growth of the Dieffenbachia plants, measured in terms of height, number of leaves, or overall vitality.
Over the 30-day period, the student observed and documented the growth of the plants, noting any noticeable differences in height, leaf development, or overall health between the fertilized and non-fertilized plants.
At the end of the experiment, by comparing the growth of plants with and without the liquid fertilizer, the student could determine if the addition of fertilizer had any significant impact on the growth and health of Dieffenbachia plants.
This information can be crucial for optimizing the care and growth of these plants.
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Which endocrine glands arouse the body, regulate salt balance, adjust the body to stress, and affect sexual functioning?
The adrenal glands are crucial for arousing the body, regulating salt balance, adjusting to stress, and affecting sexual functioning by producing hormones like epinephrine and norepinephrine, which activate the body's fight-or-flight response.
The endocrine glands that play key roles in arousing the body, regulating salt balance, adjusting the body to stress, and affecting sexual functioning are the adrenal glands. These glands are located atop each kidney and produce hormones crucial for the body's response to stress such as epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones stimulate the sympathetic division of the autonomic nervous system (ANS), causing increased heart and lung activity, dilation of the pupils, and a boost in blood sugar levels, giving the body a surge of energy.
Furthermore, the adrenal glands contribute to the regulation of salt and water balance via the secretion of mineralocorticoids like aldosterone. They are also involved in metabolism, the immune system, and sexual development and function. This highlights the integral role of the adrenal glands in managing responses to external threats and stress, maintaining fluid and electrolyte balance, and supporting sexual health.
What theory of hearing contends that the perception of a sound's frequency depends on how often the auditory nerve fires?
Answer:
The frequency theory of hearing
Explanation:
The frequency theory of hearing contends that the perception of a sound's frequency depends on how often the auditory nerve fires.
The frequency theory of hearing pinpoints that the frequency of the auditory nerve's impulses coincides to the frequency of a tone, which makes it easy to distinguish its pitch. It causes the neural signals speed to go in line with the brain to distinguish the pitch.
Place theory says that the perception of pitch is connected with vibration of certain portions of the basilar membrane, and the frequency theory says the perception of pitch is connected with the frequency at which the whole basilar membrane vibrates.
Answer: The frequency theory of hearing
Explanation:
The frequency theory of hearing states that the rate at which auditory nerve impulses occurs is associated with the frequency of a tone whose pitch is been detected. It simply explains that it is the pulse which travels up to the auditory nerve that carries the sound that we hear for the brain to process and thus there is a match between the pulse rate and the sound being heard. The theory was created by William Rutherford a British Physiologist.
In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In thewestern United States, pronghorns and cattle often associate with one another in the same openrangeland. Some of these fleas develop a strong preference for cattle blood and mate only withother fleas that prefer cattle blood. The host mammal can be considered as the fleasʹhabitat. If thissituation persists, and new species evolve, this would be an example of _____.A) allopatric speciation and gametic isolationB) sympatric speciation and temporal isolationC) allopatric speciation and habitat isolationD) sympatric speciation and habitat isolation
Answer:
D) sympatric speciation and habitat isolation
Explanation:
Sympatric isolation is a form of evolutionary process whereby different species from an ancestral origin evolve within the same geographical environment as a result of reproductive isolation.
Habitat isolation is a form of reproductive isolation which occurs when two populations of a species inhabiting overlapping habitats become unable to interbreed with each other.
Reproductive isolation (habitat isolation) that occurs in the fleas is as a result of the new species becoming separate from it's ancestral species which feed only on pronghorn antelopes, although both species can still be found in the same geographical location (rangeland). The new species now have preference for cattle blood, and so are now found on cattle.
In the situation of the two new species of flea that would evolve, it can be said to an example of sympatric speciation and habitat isolation, since the host mammal is assumed to be their habitat and both the cattle and pronghorns often associate with one another in the same open rangeland.
In a certain species of plant, flowers occur in three colors: blue, pink, and white. A pure-breeding pink plant is mated with a pure-breeding white plant. All of the F1 are blue. When the blue F1 plants are selfed, the F2 occurs in the ratio 9 blue:3 pink:4 whitE. How many gene pairs control the flower color phenotype?
Answer: If the F2 occurs in the ratio 9 blue:3 pink:4 white, one gene pair (i.e 2 genes) control the flower color phenotype.
Explanation: This principle is called INCOMPLETE DOMINANCE where one gene (dominant) won't completely override the other (recessive).
Let assume B represents the dominant gene and b represents the reccesive gene. Let also assume that Blue color is dominant over white color. We can assign the genotype as follows;
Homozygous dominant genes BB will produce Blue color
Homozygous recessive genes bb will produce white color
Heterozygous genes Bb will produce pink color.
Therefore, a pair of gene ( 2 genes) will determine the flower color phenotype.
In a certain species of plant, the flower color phenotype is controlled by two gene pairs. The F1 generation consists of blue flowers, which suggests that blue color is dominant over pink and white. The F2 generation exhibits a 9:3:4 phenotypic ratio of blue:pink:white.
Explanation:The flower color phenotype in the given species of plant is controlled by two gene pairs. Each gene pair contains two alleles, which can either be dominant or recessive. The pink parent plant is homozygous for the dominant allele, resulting in the pink color, while the white parent plant is homozygous for the recessive allele, resulting in the white color.
When the pink plant is crossed with the white plant, their offspring (F1 generation) all have the dominant allele for blue color, resulting in blue flowers. This suggests that the blue color is dominant over both pink and white. As a result, the blue F1 plants are heterozygous for the blue allele
When the blue F1 plants are self-fertilized, the resulting offspring (F2 generation) show a phenotypic ratio of 9 blue:3 pink:4 white. This indicates that the blue color is controlled by two gene pairs, as the ratio follows a classic Mendelian dihybrid ratio.
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Two parents are both heterozygous for the autosomal recessive allele for albinism. What is the probability that their first child will be an albino, their second child will be an albino, and their third child will have normal pigmentation in that order?
Answer:
Probability that their first child will be an albino = 1/4;
Probability that their second child will be an albino is 1/4;
Probability that their third child will have normal pigmentation = 3/4.
Total combined probability of these 3 children = 1/4 x 1/4 x 3/4 = 3/64.
Explanation:
Autosomal recessive disorders are the ones in which disease occurs only if recessive alleles are present in both the locus of a particular gene's allelic positions.
Here both the parents are heterozygous for albinism allele. The probability of allelic combinations of their children is shown as under:
Parentals: Aa x Aa
/ | | \
Progeny: AA Aa Aa aa
The birth of children is independent event so rule of multiplication will be applicable here.
Probability that their first child will be an albino is 1/4 because out of 4 children 1 has the probability of being born with allelic combination 'aa'.
Probability that their second child will be an albino is 1/4 and the reason is same as above.
Probability that their third child will have normal pigmentation is 3/4 because AA, Aa and Aa are 3 children with normal pigmentation.
So the total combined probability is 1/4 x 1/4 x 3/4 = 3/64.
For two heterozygous parents, the probability their first two children will be albino and the third will have normal pigmentation is 4.6875%, as each genetic makeup is an independent event.
Explanation:The subject of this question pertains to genetics, specifically the inheritance of the autosomal recessive allele for albinism. When both parents are heterozygous, each child has a 25% chance of being affected by albinism (both receive the recessive allele). Consequently, the probability of their first child, second child being albino and third child being normal (does not have the condition) would be calculated as 0.25 * 0.25 * 0.75 = 0.046875 or 4.6875%. The child's status does not influence the probability of the subsequent child's genetic makeup because each child's genetic makeup is an independent event.
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Nima excels at working with numbers in subjects such as calculus and algebra. This exemplifies ________ intelligence.
a) bodily kinesthetic
b) interpersonal
c) logical-mathematical
d) spatial
Answer:
c) logical-mathematical
Explanation:
There are many kind of intelligence, people with logical-mathematical intelligence is attracted to hard facts and numerical data (calculus and algebra), they can make subjective analysis and investigation using the scientific method.
I hope you find this information useful and interesting! Good luck!
Nima excels at working with numbers in subjects such as calculus and algebra. This exemplifies logical-mathematical intelligence.
Logical Mathematical Intelligence is the ability to solve problems logically and identify solutions easily. This also involves the ability of being able to work with numbers easily.
Logical-mathematical intelligence also involves the recognition of patterns easily.
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The doctrine that there are functionally two distinct ways in which our eyes work, the photopic, associated with the cones, and the scotopic, associated with the rods, is known as the ______ theory of vision.
Answer:
Duplex theory of vision
Explanation:
The duplex theory of vision suggests that the eyes work functionally in two different ways: the scotopic system which is formed of the rod cells and allows the vision in the low light conditions and the photopic system which is formed of the cone cells and allow us to see in the light conditions.
The duplex theory arose due to the different spectral absorption by different photoreceptors of the eye, the differences in the sensitivity to the light and different summation properties.
Thus, Duplex theory of vision is the correct answer.
Drugs that have the same effect as acetylcholine, which causes the pupil to constrict, are called __________ drugs.
Answer:
The correct answer is cholinergic drugs.
Explanation:
Cholinergic drugs refer to a broad variety of drugs that works on the parasympathetic nervous system. These drugs function by increasing the activities of acetylcholine, which is a chemical messenger or a neurotransmitter in the brain. The influences of upsurged acetylcholine are regarded as the everyday function of the body like digestion, salivation, relaxation of skeletal muscle, and constriction of pupils.
The cholinergic drugs function by preventing the enzyme, which dissociates acetylcholine, and results in the production of naturally occurring acetylcholine that lasts for a prolonged time.
26. When Peter touches a warm radiator, hest is transferred to his body by
A, convection,
B. radiation,
C. Insulation,
D. conduction.
Answer: The answer is D) Conduction.
Explanation:
Assume that an Aa animal produces four sperm from the same meiosis. A geneticist examines each of the four products of this meiosis and finds that one of them carries the a allele, one carries the A allele, one carries both the A and a alleles and one has neither allele. This result is not consistent with which genetic concept?
Answer:
The correct answer is - principle of segregation.
Explanation:
The principle of segregation explains that the in what manner pair of gene type or alleles are separated into sex or reproductive cells. These variants are known as the gene alleles. These are first studied by the Mendel as the traits in 1865. In this case the results are not consistent with this principle of segregation concept.
Thus, the correct answer is - principle of segregation.
A______________is a type of cell that receives and transmits information in the Central Nervous System
(CNS – brain and spinal cord) and the Peripheral Nervous System (PNS – afferent & efferent nerves).
Answer: Neurons
Explanation:
Neurons are the types of cells found in the body. It is like the other cells of the body but it is different in its functioning.
The neurons in the body is equipped for the transmission of signals throughout the body.
It is the basic functional unit of the brain and carries the information from brain to the various parts of the body.
If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?A) A and D
B) B and D
C) B and C
D) D and E
D and E
Explanation:
The organisms are classified on the basis of their similarities and dissimilarities.
The taxonomic ranks are: Kingdom > Phylum> class > Order > family > genus > species.
As we move from kingdom towards the species the degree of similarities increases i.e. organisms that are grouped within a kingdom may have greater number of dissimilarities among them again more similar organisms are grouped into phylum, further organisms whuich are more similar within a phylum are grouped into class and this goes on.
In a species the individuals are very similar and have least number of dissimilarities among them.
In the given situation, A,B and C are of same class But they are in different order but C,D and E are of same order.
So C is more similar to A and B when compared to D and E.
Thus, D and E are expected to show greatest degree of structural homology.
When individuals of the same species are reproductively isolated, genetic differences may accumulate in sufficient number so that new species could emerge. Such an event would be an example of Group of answer choices A.equilibrium. B.macroevolution. C.microevolution. D.the founder effect.
Answer:
B.macroevolution
Explanation:
Macroevolution is a type of evolutionary change pattern and process that brings about the emergence of new species through isolation, genetic drift, natural selection or gene flow. Macroevolution occurs on a larger scale above species level, unlike microevolution that is restricted to within a species or population.
Answer:
B. Macro-evolution.
Explanation:
It is a type of macro-evolution because in a separated and isolated specie there is a gradual but abrupt change is going to take place and a new specie is going to emerge in the environment. The new specie will have a effect on the value of it's mother specie and because the new specie is better adapted version of the previous one in particular environment. It may become possible that the new specie will continue to thrive and her mother specie will become extinct as the time passes by...
Mario is highly afraid of spiders. Which part of the brain would be activated if he were to enter a room that had a lot of spiders?
Answer: Hypothalamus
Explanation:
Due to the fear of spiders, Mario is likely to have the following sensations: sweating, shivering, increased heartbeat, raised blood pressure.
And all these are controlled by the hypothalamus, a part of the Fore-brain
The amygdala is activated when Mario enters a room with spiders, triggering a fear response as part of the body's sympathetic nervous system. This fear can be intense due to evolutionary predispositions and have significant impacts on one's life.
When Mario, who is highly afraid of spiders, enters a room filled with spiders, the part of the brain that would be activated is the amygdala. The amygdala is responsible for processing emotions, such as fear, and it triggers the fear response. This response involves a cascade of physiological changes including increased heart rate, rapid breathing, and sweating, which are all part of the body's sympathetic nervous system response to perceived threats. The amygdala works in conjunction with other brain structures, such as the hypothalamus, to orchestrate the body's reaction to fear-inducing stimuli. This nervous system activity is automatic and can occur even if the threat is not real—as in the case of a person mistaking a piece of fuzz for a spider—showing the power of perception in eliciting a fear response.
In Mario's case, his intense fear of spiders, also known as arachnophobia, may have been influenced by evolutionary predispositions, as humans have historically associated spiders with danger, despite the fact that most spiders are not harmful to humans. The effect of fear on an individual’s life can be profound, as observed with Janet's extreme reaction to spiders limiting her activities and leading to job loss.
Scientists use a standardized taxonomic system to separate organisms into hierarchical groups based on similarities and differences in their structural and genetic characteristics.
Which of the following best explains why a standardized classification system is important to the scientific community?
It allows different kinds of organisms to be easily identified based on their characteristics.
Answer:
Option B, It allows different kinds of organisms to be easily identified based on their characteristics
Explanation:
Options for the question are
It provides a detailed evolutionary history of all the known organisms on Earth It allows different kinds of organisms to be easily identified based on their characteristics It allows scientists to group organisms based on their personal preference It prevents people who are not scientists from studying and identifying organisms. It allows scientists to to group organisms based on their personal preference It prevents people who are not scientists from studying and identifying organisms Solution
A standardized taxonomic system provides a common basis for the entire scientist community to identify and classify organism on common grounds and hence leading to a standardized organism classification across the globe.
This also groups organisms into different kingdoms, taxas and classes with defined hierarchy and description of shared traits and characteristics. It also provides scope for inclusion of newly discovered species thereby making the standardized taxonomic system flexible
Hence, option B is correct
Answer:
b
Explanation:
i got it right on SI
Nervous tissue can be found mainly in the ____________ , spinal cord, and in the limbs as ____________ .
Answer:
1. Brain
2. Peripheral nerves
Explanation:
The nervous tissue or the nervous system is a system in the humans or animals formed by the neurons.
The nervous system can be categorised into two types based on the structure and functions: the peripheral nervous system and the central nervous system.
The central system of neurons comprises of the neurons present in the spinal cord and the brain and the peripheral system which comprises the nerves of the organs present except the brain and the spinal cord like the nerves in the limbs (legs, arms).
Thus, Brain and Peripheral nerves are correct.
Predict how many genetically different offspring could be produced by outcrossing two 2n=4 individuals?
Answer:
16 genetically different offsprings
Explanation:
The diploid state of this organism has 4 chromosomes, hence, when it undergoes meiosis, it will produce gametes with 2 chromosomes each.
The number of different possible gamete combinations can be got using the formula 2^n, which n is the number of chromosomes in each gamete.
Therefore, 2^2 = 4 possible combinations of gametes.
If one of the individuals will produce 4 possible combinations of gametes, a combination of two of these gametes will result in offsprings with (4)^2 possible combinations of different offsprings. i.e. 16 possible genetically different offsprings.
"Founders of social psychology" Norman Triplett and Max Ringelmann both did research examining _______.
A) the influence groups exert on their members.
B) the impact of the presence of others on performance.
C) how behaviors are shaped by perceptions.
D) the impact of different leadership strategies on group performance.
The division of the nervous system that allows the brain and the spinal cord to communicate with the sensory systems of the eyes, ears, skin, and mouth, and allows the brain and spinal cord to control the muscles and glands of the body is called the ________.
Answer:
peripheral nervous system
Explanation:
The peripheral nervous system includes all nervous tissue except form the central nervous system. The afferent division of this nervous system delivers the sensory information from the sensory receptors to the central nervous system. In this way, the information from the somatic and special sensory organs such as the nose, tongue, eyes, and ears is delivered to the central nervous system.
The motor division of the peripheral nervous system includes somatic and autonomic divisions. The somatic division is the motor division that conveys output from the CNS to skeletal muscles while the autonomic division sends the information from the CNS to smooth muscle, cardiac muscle, and glands.
The division of the nervous system responsible for facilitating communication between the brain, spinal cord, sensory systems (eyes, ears, skin, mouth), muscles, and glands is known as the "Peripheral Nervous System" (PNS).
The division of the nervous system that allows the brain and the spinal cord to communicate with the sensory systems of the eyes, ears, skin, and mouth, while also enabling them to control the muscles and glands of the body, is called the "Peripheral Nervous System" (PNS).
The PNS serves as a bridge between the central nervous system (CNS), which includes the brain and spinal cord, and the external environment. It consists of two main components:
1. Sensory (Afferent) Division: This component collects sensory information from various receptors throughout the body, including those in the eyes (vision), ears (hearing and balance), skin (touch, temperature, and pain), and mouth (taste and pressure). This sensory information is then transmitted to the CNS for processing and interpretation.
2. Motor (Efferent) Division: The motor division of the PNS carries commands and signals from the CNS to the muscles and glands, enabling voluntary muscle movements (somatic nervous system) and regulating involuntary functions like heart rate, digestion, and glandular secretions (autonomic nervous system).
The PNS plays a crucial role in sensory perception, motor control, and maintaining homeostasis by relaying information between the central nervous system and the body's external and internal environments.
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Which type of operon, an inducible one or a repressible one, would an organism likely use to produce enzymes and other proteins required for the cell to manufacture a molecule needed from smaller molecules in the environment?
Answer:
Repressible operon
Explanation:
In a repressible operon, a corepressor binds to the repressor to activate it. The active repressor then binds to the operator to prevent the expression of the operon. These operons have the genes that code for the enzymes required to make molecules from simpler substances. When the molecule is already present in the cell, it serves as a corepressor to prevent the expression of the genes.
For example, tryptophan operon is expressed only when tryptophan is not present in the cells. Tryptophan serves as a corepressor to prevent the expression of the operon.
An organism would likely use a repressible operon to produce enzymes needed to manufacture a molecule from smaller environmental molecules.
It is likely that the organism will make use of a repressible operon in order to produce enzymes and other proteins necessary for it to manufacture a necessary molecule from smaller molecules in the environment. Repressible operons, like the tryptophan (trp) operon, contain qualities encoding compounds important for biosynthetic pathways. These operons are communicated just when the finished result (e.g., tryptophan) is required by the cell. When the product reaches a sufficient level, it binds to the repressor protein, causing it to be activated to bind to the operator region of the operon, thereby halting further transcription. This component guarantees that the cell doesn't squander energy delivering superfluous proteins when adequate amounts of the eventual outcome are accessible.Thermoreceptors detect body temperature and send impulses to the brain for analysis. If body temperature is low, the brain will signal skeletal muscles to perform brief, repeated contractions to help generate heat. In this example, what is the effector?
A. Skeletal muscles
B. Body temperature
C. Brain
D. Thermoreceptors
Answer:
A. Skeletal muscles
Explanation:
An effector is a group of cells, an organ, gland or any part of the body that acts to bring about a change in response to a nerve impulse from the CNS.
In the case of thermogenesis as stated in the question above, where a drop in temperature is detected by thermoreceptors in the CNS, the part of the body that responds in returning the body temperature back to its baseline are the skeletal muscles. The skeletal muscles are the effectors that responded in repeated contracions to generate heat.
Answer:
A
Explanation:
In order to maintain homeostatic balance in human, negative feedback loop and sometimes positive feedback loop are usually employed. The control mechanism consists of receptors and effectors (muscles and glands). The Receptors are sensory cells that acts like sensors to detect changes stimuli from the internal and external environments and relay these as input to the control center the brain. The brain processes the input and send the information as output to the effectors to bring about a corrective effects.
The control by the negative and positive loop are usually within the set-points so that the homeostatic balance of the body is maintained.
In this present scenario, the imbalance in body temperature (drop )is detected by the receptors in the skin (thermoreceptos, so named because they are sensitive to heat). They sent input as temperature fluctuations to the brain the control center.Analysis by the brain is relayed as output to the effectors (skeletal muscles) to contract, repeatedly. This is shivering. It is a thermogenic mechanism of increasing body temperature when it drops.
Therefore the skeletal muscles is the effector because , it causes a biological change(shivering) in the body reverse the rise in body temperature, and returns it to normal level.
The entire process is called thermogenesis. Once the temperature reached the set-point the thermoreceptors, sense this and send corrective input for the brain to stop the stimulation of the temperature control center : hypothalamus to reduce the output to the effectors Therefore, he skeletal muscles relaxed. and shivering is stopped
Although this is a corrective measure, it has disadvantage of withdrawing heat energy from the body core temperature via vasodilitation and loss to the surrounding environment via convention.
At an initial examination in Oxford, Mass., migraine headache was found in 5 of 1,000 men aged 30 to 35 years and in 10 of 1,000 women aged 30 to 35 years. The inference that women have a two times greater risk of developing migraine headache than do men in this age group is:___________a. Correctb. Incorrect, because a ratio has been used to compare male and female ratesc. Incorrect, because of failure to recognize the effect of age in the two groupsd. Incorrect, because no data for a comparison or control group are givene. Incorrect, because of failure to distinguish between incidence and prevalence
Final answer:
The conclusion that women aged 30 to 35 have twice the risk of developing migraines as men do is supported by the given data, though additional factors influencing prevalence should also be considered.
Explanation:
The inference that women have a two times greater risk of developing migraine headaches than men in the 30 to 35 age group, based on the data that 5 of 1,000 men and 10 of 1,000 women were found to have migraines, is correct. This conclusion is drawn from directly comparing the prevalence rates within the same age group for both genders, showing that migraines were found twice as often in women as in men.
It is important, however, to consider additional factors that might influence migraine prevalence such as hormonal differences, societal roles, and stress levels associated with traditional gender roles. Moreover, the explanation for higher rates of migraines in women could be partly attributed to differences in ethno-etiology, which offers various cultural explanations for health-related problems, as well as biomedical explanations which include a range of physiological and environmental factors.
Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes.
No new settlers arrive,and nobody leaves the island.After a few generations,the percentage of blue-eyed individuals increases from the original zero to 25 percent.This is probably due to which of the following factors?
A) genetic drift
B) mutation
C) gene flow
Answer:
Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes. No new settlers arrive,and nobody leaves the island.After a few generations,the percentage of blue-eyed individuals increases from the original zero to 25 percent.This is probably due to which of the following factors?
genetic drift
Explanation:
Genetic drift entails when there are changes in the gene frequency which occur in a gene that is existing. From the analogy above, it is a known fact that only gneetic drift could allow such to happen as mutation will only occur with a sudden change of gene which is not the case described above
Final answer:
The increase in blue-eyed individuals in an isolated island population is likely due to genetic drift (option A), a random fluctuation in allele frequencies that is pronounced in small populations.
Explanation:
The increase in the percentage of blue-eyed individuals in a small, isolated population from 0 to 25% is most likely due to option A) genetic drift. Genetic drift is a mechanism of evolution that refers to random changes in the frequencies of alleles within a population's gene pool. This can lead to the increase or decrease of specific alleles, and is especially pronounced in small populations where chance events can have a more significant impact on the gene pool. An initial population where all individuals have brown eyes, but one individual carries the allele for blue eyes, is an example of how genetic drift could cause a notable change over generations if the alleles are passed on randomly.
In the given scenario, the heterozygous European man carrying the recessive gene for blue eyes could have passed it on to his offspring, and due to the small population size and isolation of the island, these traits could become more common by chance over a few generations. A mutation would imply a change in the genetic material which is not mentioned in the scenario, and gene flow requires the movement of genes between populations, which is also not applicable here as the population is isolated.
Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing selection
Answer:
Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing selection
The Answer is option A (Disruptive selection)
Explanation:
Selection can either shift the mean value of a trait, reduce the trait's variation, or increase its variation.
Genetic variation which allows natural selection to increase or decrease frequency of alleles already in the population is a source of phenotypic variation as it refers to differences in all the hereditary information of members of the same species.
Disruptive Selection is important in maintaining variation and initiating speciation as it Increases Variation by favoring alleles corresponding to more extreme phenotypes. But for it to occur, the mean phenotype has to experience the lowest fitness. Disruptive selection affects the frequency distributions of alleles and genotypes within a population.
Disruptive selection is based on the variance of a trait in a population as it increases genetic variance by equalizing the frequencies of existing alleles at polymorphic loci (a genetic loci with two or more alleles). Disruptive selection maintains and may even increase variation in natural populations by favoring extreme phenotypes, individuals with extreme values for a trait have greater reproductive success than individuals with intermediate values.
B) Disruptive selection is the right response. Natural selection that promotes extreme phenotypes while decreasing the predominance of intermediate phenotypes is known as disruptive selection.
A population's genetic diversity may rise as a result of this kind of selection.
Individuals with extreme qualities at both ends of the phenotypic continuum benefit more from disruptive selection than do people with moderate features.
As a result, while the intermediate qualities are being chosen against, the extreme features gradually grow more widespread in the population.
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Ribosomes are found: Select one: a. on smooth endoplasmic reticulum b. on the rough endoplasmic reticulum c. in the cytoplasm d. in the cytoplasm and on the rough endoplasmic reticulum e. on the Golgi apparatus
Answer:
The answers is D
Explanation:
Ribosomes are numerous, small, round organelles that perform the function of protein production in the cell. They are found as freely-floating organelles in the cytoplasm and attached to the rough endoplasmic reticulum.
Ribosomes found as free-floating within the cytoplasm produce protein to be utilized within the cell while ribosomes attached to the endoplasmic reticulum are used inside the cell or outside the cell.