Final answer:
Sitting for a long time on a long airplane flight can lead to blood pooling below the knees and increase the risk of deep vein thrombosis (DVT).
Explanation:
Sitting for hours on a long airplane flight can cause blood pooling below the knees due to a condition called deep vein thrombosis (DVT). DVT occurs when a blood clot forms in the deep veins, usually in the legs. When you sit for a long time, especially in cramped quarters, blood can pool in the deep veins of the legs, increasing the risk of a blood clot. Sitting for a long time on a long airplane flight can lead to blood pooling below the knees and increase the risk of deep vein thrombosis (DVT).
If a student wanted to separate the colored pigments from a green leaf, the student would likely consider the separation technique of: a. crystallization b. chromatography c. filtering d. distillation
Answer:b
Explanation:because it separates green pigment from leafs
At the zoo, you notice that the scientific name for a tiger is Panthera tigris. Later, you see that the lion is called Panthera leo. Given what you know about the hierarchal organization of life, these two organisms must share the same: _______-
Answer:
Genus
Explanation:
In the scientific name "Panthera tigris", Panthera is the name of the genus and the "tigris" is the name of the species. Similarly in the name "Panthera leo", the name "Panthera" denotes the genus while "leo" is the species. This means that the tiger and lion belong to the same genus. They both belong to the genus "Panthera".
Though the species of the tiger is "tigris" and that of the lion is "leo". Both are the species of the same genus since the genus includes closely related species. The members of these different species can not interbreed but share some common features as they belong to the same genus.
Final answer:
Tigers and lions share the same genus, Panthera, as indicated by their scientific names Panthera tigris and Panthera leo, but they are different species.
Explanation:
At the zoo, the scientific names Panthera tigris for a tiger and Panthera leo for a lion indicate that these two organisms must share the same genus. The binomial nomenclature system used for naming species consists of two components: the generic epithet or genus, and the specific epithet or species. The genus Panthera connects lions, tigers, leopards, and jaguars, which are all large cats with the ability to roar. The species name then specifies which particular species is in question within this genus. Hence, lions (Panthera leo) and tigers (Panthera tigris) share the genus Panthera but are different species within this genus.
Marginal benefit is A. the difference between the highest price a consumer is willing to pay and the price the consumer actually pays. B. the additional benefit from consuming one more unit. C. the additional cost of producing one more unit. D. a legally determined maximum price that sellers may charge. Why is the demand curve referred to as a marginal benefit curve? A. It shows the price consumers actually pay to consume a product. B. It shows the difference between the highest price a consumer is willing to pay and the lowest price a firm would be willing to accept. C. It shows the difference between the highest price a consumer is willing to pay and the marginal benefit of consumption. D. It shows the willingness of firms to supply a product at different prices. E. It shows the willingness of consumers to purchase a product at different prices.
Answer:
Marginal Benefit : B. the additional benefit from consuming one more unit.
Demand Curve = Marginal Benefit Curve as : E. It shows the willingness of consumers to purchase a product at different prices.
Explanation:
Benefit is the rise in satisfaction from consumption. Marginal Benefit is the additional benefit from consuming an additional unit. So, it is addition to satisfaction with an additional consumption i.e Marginal Utility (MU).
Consumer purchases a good only if : Its marginal benefit i.e MU ≥ its marginal cost i,e price. As MU < Price implies additional benefit < additional cost, & consumer will not consume at this point.
So, Marginal Utility/ Marginal Benefit reflects consumer's willingness to pay for a good's consumption. Hence, Demand Curve is also called Marginal Benefit Curve.
If a peptide was composed entirely of alpha-helical structure and found to contain an integer number of complete turns, which of the following would be a possible number of amino acid residues in the peptide?
A) 36
B) 60
C) 20
D) 32
Answer:
A
Explanation:
The possible number of amino acid residues in the peptide composed entirely of alpha-helical structure and found to contain an integer number of complete turns is 36
_____ genetics uses advanced technology to actually manipulate genes in order to determine their effect on behavior.
Answer:
The correct answer is - molecular genetics.
Explanation:
Molecular genetics is the subfield or the branch of the genetics that dealing with the manipulation of the organism at the molecular level which is a gene or genetic material with the help of the advanced technology.
It is an investigating approach that helps in determining the effect of the genes or genetic material that is manipulated on the behavior of the organism.
Thus, the correct answer is - molecular genetics.
Edgar cannot sleep because he is terribly worried about his research paper. So Edgar decides to get out of bed and continue working on the paper. Although he stays up to nearly 3 a.m., he is relieved that it is done and easily falls off to sleep. In the future, Edgar will be more likely to finish his work before going to bed so that he can avoid the worry and sleeplessness. Such behavior is an example of __________.a. positive reinforcement.
b. negative reinforcement.
c. punishment.
d. classical conditioning.
Edgar can't sleep as he is worried about the research paper. So he finished all his work and got to bed at 3. This is an example of positive reinforcement. Option A is the correct answer for this situation.
What is positive reinforcement?
Positive reinforcement is a phenomenon that motivates the person to do more work. In the case of Edgar, he can't sleep due to the pending work related to his research paper. This gave him sleeplessness.
When he completed his work, only then could he go to sleep peacefully. This is an example of positive reinforcement. His anxiety related to the pending work is gone, so let him sleep. In the future, he would be more likely to do this. He would try to finish all his work before going to bed.
Hence, This is an example of positive reinforcement. Option A is the correct answer for this situation.
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Some humans have genes that make them resistant to infection by HIV. Would human populations likely evolve differently in areas of the world where HIV infection rates are high?
Answer:
Yes, the population can evolve differently with resistance gene to the HIV
Explanation:
AIDS is a deadly disease caused by the Human immunodeficiency virus. The HIV infection ultimately results in the death of the host and the cases are increasing every year.
If in the population of the area affected with the HIV AIDS develop some resistant gene to the disease, therefore, the resistant gene will be passed on to the generation and the population will evolve differently as a measure or response of adaptation and natural selection.
The case of sickle cell anaemia with modified shapes of red blood cell in the population of Africa, a resistance mechanism to malaria can act as evidence to the HIV case.
Thus, Yes, the population can evolve differently with resistance gene to HIV is the correct answer.
Neurospora crassa was one of the first eukaryotic microbes to be adopted by geneticists as a model organism. It is a haploid fungus (n = 7) found growing on dead vegetation. When an assexual spore germinates, it produces a tubular structure that extends rapidy by tip growth, and throws off multiple side branches. The result is a mass of branched threads called hyphae, which consitute a colony. a) Give two reasons why Neurospora crassa lends itself well to its use as a model organism. b) Two albino strains of Neurospora crassa were isolated. When either one was mated with wild type (pink), it produced ½ albino and ½ wild-type. What can you deduce about the mutations on each of the albino strains? Your Answer:
Answer:
A) They have low-maintenance and are easy to keep track of for mutations.
B) The deduction can be "Single Gene Mutation"
Explanation:
After examining the example given in the question on Neurospora crassa and the details about how they reproduce, the following points can be made regarding the questions;
A) It is stated that they form a colony in time and that they are asexual spores and the first reason to choose them would be because they contain somatic cells (which refer to the cells other than reproductive cells) and non-motile gonidia which can multiply by dividing themselves and these properties make the colony's maintenance easy. And since they multiply by division, it is easier to keep track of the occuring mutations.
B) Given the information in the question that the mating is between an albino strain and a wild type, and then between two albino strains which have the same genotype. The results indicate that the strains have gone through single gene mutation during the process.
I hope this answer helps.
Answer:
a) Neurospora crassa lends itself well to its use as a model organism due to this two reasons:
-It is asexual.
It can reproduce in the absence of a partner. This characteristic nature makes it inexpensive to use.
-It shows rapid growth rate.
This nature makes it easy to study how it reproduce and its mutations without the need to wait a prolonged time for the maturation of offspring.
b) we can deduce about the mutations on each of the albino strains as each one of it is a singular gene mutation. Multiple gene mutations will lead to reduced wild type progeny.
All of the following are true of most vitamins EXCEPT A. they enhance enzymatic activity. B. they are inorganic molecules. C. they are essential for good health. D. they are micronutrients. E. they can act as cofactors.
Answer:
They are in organic
Explanation:
Vitamins are organic compounds derived from plants or animals that are needed in the body at small quantities.
They help in the body's metabolism since they enhance enzymatic activities and can act as co-factors.
They are essential for good health such as vitamin A helps in improving eye sight.
Lack of certain essential vitamins can lead to disease ,lack of vitamin D can lead to Rickets.
Answer:
The answer is B. they are inorganic molecules.
Explanation:
vitamins are organic molecules that are essential micronutrient to organism and are needed in small quantities for the functioning of the body.
You are responding to a call where an 8-year-old has been stung by a wasp. His skin is pale with patches of raised red spots on his hands, arms, and face. These spots are most likely what?
A) Angioedema
B) Acne
C) Urticaria
D) A fungal infection
The raised red spots are most likely urticaria, a skin condition characterized by itchy red welts caused by an allergic reaction.
Explanation:The raised red spots on the hands, arms, and face of the 8-year-old student who was stung by a wasp are most likely urticaria.
Urticaria, also known as hives, is a skin condition characterized by itchy red welts or patches that can appear and disappear quickly. It is usually caused by an allergic reaction to certain substances, such as insect bites or stings.
In this case, the red spots are a result of the release of histamine and other mediators in response to the wasp sting, leading to the dilation of blood vessels and fluid leakage.
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Which statement is true?
A cell generates order by decreasing the entropy of its surroundings.
A. A cell takes in heat from the environment to power its biosynthetic reactions, thus obeying the second law of thermodynamics.
B. Cells obey the first law of thermodynamics, but are exempt from the second law.
C. The breakdown of food molecules generates heat, which cells then use to drive the synthesis of large molecules.
D. The heat released by an animal cell comes from the chemical-bond energy present in the food molecules it metabolizes.
Answer: The answer is D
Explanation:
The heat released by an animal cell comes from the chemical-bond energy present in the food molecules it metabolizes is the true statement about cells.
What are the functions of cells?Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions.
Cells provide six main functions. They provide structure and support, facilitate growth through mitosis, allow passive and active transport, produce energy, create metabolic reactions and aid in reproduction.
They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body's hereditary material and can make copies of themselves.
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Recovery periods following each action potential help prevent propagation of the action potential in the wrong direction. A recovery period in which the axon is not responsive to any strength of stimulus is called _______.
Answer:
Refractory period
Explanation:
The refractory period is the time interval after the beginning of an action potential. During this time, neurons can not fire the next action potential irrespective of the presence of a threshold stimulus. This occurs so as to ensure the unidirectional flow of the nerve impulses. The absolute refractory period occurs when the Na+ channels are activated and then inactivated. These inactive channels are required to resume the resting stage before they can reopen.
The practice of behaviors and lifestyle choices that promote both physical and mental health is called ________.
Answer: Wellness
Explanation:
Wellness is an active process of practice behaviors and lifestyle choices that promote both physical and mental health. Wellness involves the practice of becoming aware of and making choices toward a healthy and fulfilling life. Wellness is more than being free from illness. it is a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity. Maintaining an optimal level of wellness is absolutely crucial to live a higher quality life. Wellness matters.
Answer:
wellness
Explanation:
Fish must have oxygen in the water to survive. How would a decrease in oxygen affect the fish in the aquarium? The variety of fish would increase. The number of fish would decrease. The number of fish would increase. The variety of fish would decrease.
Answer:
The number of fish would decrease.
Explanation:
Ecological hypoxia can be described as a condition in which the oxygen level drops to such low levels in the aquatic ecosystem that it is no longer able to support aquatic life. In such a condition, the number of fishes declines at a rapid rate because fishes require oxygen as an essential element. Also, those fishes which do not have better adaptations to survive might get totally wiped out from the aquatic ecosystem.
Which statements about viruses are true? Select all that apply. A. Viruses are ultramicroscopic cells. B. Viruses are infectious particles with a protein coat surrounding the nucleic acid. C. Bacteriophages are viruses that can also infect the animal cells infected by the bacteria. D. Viruses are nonliving. E. Viruses are not living.
Answer:
Answers A, B, C, D and E are all correct
Explanation:
Viruses are non living, ultramicroscopic cells, infectious particles with a protein coat surrounding the nucleic acid that replicate inside any life form and infeft them.
Bacteriophages, like viruses that can also infect the animal cells infected by the bacteria.
Answer:
Viruses are not living
Explanation:
Because it has no cells therefore it has no life so if it dies once it touches a surface un like bacteria
What happens when consumers eat producers in the energy pyramid? A Energy transfer forms from the producer to the consumer. B energy transfers from consumer to producer C energy transfers from the producer to predator D energy transfers from the consumer to the producer
Energy transfers from the producer to the consumer.
Explanation:
An organism eats to get energy that is required by its tissue to carry out metabolic activities.Organisms in an ecosystem are related to each other by there feeding habits.The producers lie at the bottom of a food chain. They bear the ability to convert the solar energy into chemical energy within the cell.They are responsible to drive the flow of energy from the ultimate source into the food chain.When consumers feed on the producers the energy conserved in the tissue of producers get transferred to the consumer in this way the enery transfers from one trophic level to another.Final answer:
When consumers eat producers in the energy pyramid, energy transfers from the producer to the consumer.
Explanation:
When consumers eat producers in the energy pyramid, energy transfers from the producer to the consumer. Producers, such as plants, obtain energy from the sun through photosynthesis and store it. When consumers, such as herbivores, eat the producers, they obtain this stored energy and use it for their own needs.
Sickle-cell anemia results from a point mutation in the HBB gene. The mutation results in the replacement of an amino acid that has a hydrophilic R-group with an amino acid that has a hydrophobic R-group on the exterior of the hemoglobin protein. Such a mutation would most likely result in altered ______.
Answer: properties of the molecule as a result of abnormal interactions between the adjacent molecules.
Explanation:
Hemoglobin is responsible for the transportation of oxygen throughout the body.It is made up of two subunits: alpha globins and beta globin. Beta-hemoglobin is created from the genetic information found on the HBB gene.A single point mutation in beta globin results in the replacement of hydrophophilic amino acid(glutamate) with hydrophobic amino acid(valine) at the sixth position.This result in the formation of mutant beta globin which along with alpha globin forms hemoglobin S also known as HbS. This results in the formation of deformed red blood cells or 'sickle' cells.
A point mutation in the HBB gene causes the substitution of a hydrophilic amino acid with a hydrophobic one in hemoglobin, leading to sickle-shaped red blood cells in sickle cell anemia.
Explanation:Sickle-cell anemia results from a point mutation in the HBB gene. This mutation leads to an amino acid substitution which changes the hemoglobin protein's structure and function. Specifically, glutamic acid in the hemoglobin β chain is replaced by valine. This single alteration out of approximately 600 amino acids in the hemoglobin protein causes it to fold abnormally. Consequently, under low-oxygen conditions, these mutated hemoglobin molecules form aggregates that cause red blood cells to become sickle-shaped. This abnormal shape impairs their ability to navigate through capillaries and deliver oxygen effectively, leading to the various symptoms of sickle cell anemia such as breathlessness, dizziness, and pain.
The endosymbiotic theory states that nonphotosynthetic prokaryotes merged with an ancestral cell and, over evolutionary time, became___________. Some of these new cells engaged in a second merging event with a photosynthetic prokaryote, possibly a cyanobacterium. The photosynthetic prokaryote eventually—over evolutionary time—became __________.
Answer:
mitochondria, chloroplast
Explanation:
According to the endosymbiotic theory chloroplast and mitochondria in eukaryotes are originated from phagocytosis of different bacteria by an ancestral cell.
The theory says that an ancestral cell engulfed a non-photosynthetic bacteria and did not digest it but evolved with it which gave rise to mitochondria in eukaryotic cells.
This theory also tells that chloroplast is originated by the phagocytosis of a photosynthetic prokaryote like cyanobacteria by ancestral cell. The genetic similarities of these organelles with bacteria proves this theory.
Researchers investigating the regulation of neurotransmitter release from presynaptic neurons proposed a model in which CDK5, a protein expressed in axon terminals, inhibits the movement of synaptic vesicles to the presynaptic membrane... to test their model, the researchers used a modified version of green fluorescent protein...based on the model, which of the following best explains why a bright green fluorescence was observed following stimulation of a presynaptic neuron?
Final answer:
Bright green fluorescence after neuron stimulation indicates neurotransmitter release from synaptic vesicles, as calcium influx due to an action potential facilitates vesicle fusion with the presynaptic membrane through exocytosis.
Explanation:
The bright green fluorescence observed following stimulation of a presynaptic neuron is likely due to the release of neurotransmitter molecules from synaptic vesicles. In the described experiment, researchers used a modified version of green fluorescent protein to visualize this process. When the presynaptic neuron is stimulated, an action potential reaches the axon terminal, causing voltage-gated Ca²+ channels to open. This results in an influx of calcium ions into the synaptic end bulb, which then interacts with the proteins on the surface of the neurotransmitter vesicles. This interaction facilitates the fusion of the vesicle with the presynaptic membrane allowing the neurotransmitter to be released into the synaptic cleft through exocytosis. The model proposed by the researchers suggests that CDK5 inhibits this process, so observing bright green fluorescence indicates that neurotransmitter vesicles are indeed reaching the presynaptic membrane and releasing their contents, which can then be visualized thanks to the fluorescent protein.
Translation in prokaryotes occurs in the ___________. Translation in eukaryotes occurs in the ___________. bio 172
Explanation:
for prokaryote and eukaryotes both the translation occurs in cytoplasm
Answer:
cytoplasm
Explanation:
Which two events occur when gravity causes a nebula to collapse into itself?
A. Nuclear fusion starts.
B. The nebula cools down.
C. A supergiant forms.
D. A new star forms.
The two events that occur when gravity causes a nebula to collapse into itself are:
A. Nuclear fusion start.
B. A new star forms.
Explanation:
Nebula are giant clouds of dust and gases.These clouds are considered as progenitors of stars and planets.The gravitational pull within these giant clouds result these large masses to collapse towards their centre.The gravitational collapse results in tremendous rise in temperature till a point where nuclear fusion begin .The stars are born out of such mechanism and act as a source of heat and light in universe.DNA can be visualized as a ladder in which the parallel rungs ("steps") would be _____.
Answer:
hydrogen bonded basesExplanation:
DNA can be visualized as a ladder in which the parallel rungs ("steps") would be hydrogen bonded bases
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A folding domain of a polypeptide chain has a primary structure containing 5 phenylalanine residues as shown below, where F represents the side chain of phenylalanine.
F F F
_|____|____|_
| |
F F
If this domain folds in one of the two orientations below, which is more likely - the one on the left or the one on the right?
Would all the side chains be inside a circle or would they be outside a circle?
a. The one on the left
b. The one on the right
b. The one on the right
They will be inside the circle.
Explanation:
Phenylalnine is an aromatic amino acid which is hydrophobic in nature.
It tends to get buried in the core of protein structure.
These phenylalanine residues isomerise to the favoured N and C terminus.
The phenylalanine residues will be inside the circle because they are hydrophobic in nature.
These residues will fold the one on the right, clockwise in the domain.
Final answer:
The correct answer is a. The one on the left
To determine which orientation of the folding domain is more likely and whether the side chains would be inside or outside a circle, we need to consider the hydrophobic interactions and steric hindrance.
Explanation:
In protein folding, hydrophobic residues tend to be buried in the interior of the protein to avoid contact with the surrounding aqueous environment, while hydrophilic residues tend to be exposed on the protein's surface. Phenylalanine (F) is a hydrophobic amino acid.
Given that there are 5 phenylalanine residues in the primary structure, the folding domain is likely to fold in a manner that maximizes the burial of these hydrophobic residues in the protein's interior. Therefore, the folding orientation that brings the phenylalanine residues closer together, allowing them to interact and form hydrophobic contacts, would be more favorable.
Looking at the two orientations provided:
The orientation on the left brings the phenylalanine residues closer together compared to the orientation on the right. In the left orientation, the phenylalanine residues are clustered together more tightly, facilitating stronger hydrophobic interactions.
In the left orientation, all the side chains would be inside a circle, as they are brought together in the interior of the protein to maximize hydrophobic interactions.
Therefore, the orientation on the left is more likely, and all the side chains would be inside a circle in this orientation.
So, the correct answer is a. The one on the left
17. According to the Mohs Hardness Scale, what's the approximate hardness of topaz?
A. 8
B. 10
C.9
D.7
Answer: (A) the answer is 8
Explanation:topaz on the scale is no 8, followed by corundum no 9 and then diamond which is the hardest on no 10
Which of the following is a correct application of one of Darwin's postulates to the Galapagos finch data from Case Study #2?
A. All the birds, no matter their beak size, were equally likely to survive during the drought.
B. Variation in beak size was present in the population of finches prior to the start of the study.
C. Beak size is not a heritable trait.
D. All the birds, no matter their beak size, were likely to have the same number of offspring during the drought.
Answer:
B. Variation in beak size was present in the population of finches prior to the start of the study
Explanation:
Hello! Charles Darwin arrived in the Galapagos Islands in 1835 and noticed that the finches had a different peak. This difference he observed in birds was what made him think that the species were not stable, but that they changed their physical characteristics to adapt to the pressures of the environment
Archaeal genomes are typically organized as circular genomes. True or false
Answer:
Archaeal genomes are typically organized as circular genomes.
True
Explanation:
The genomes pf archael are arranged in circular form just like that of bacteria
Imagine that you are observing an enzyme-catalyzed reaction in the lab. Every time you add more enzyme, the reaction rate increases proportionally until the reaction rate suddenly levels off. No other chemicals were added, and no modifications were made in the experimental setting. Why do you think the reaction rate stopped increasing?
The rate of reaction stops increasing because there is no substrate left to bound with an enzyme to increase the rate of reaction.
What is an enzyme?An enzyme is a substance that increases the rate of reaction by catalyzing the reaction.
The enzyme is called a biological catalyst.
Enzyme work when it combines with the substrate of the reaction to make products.
When the enzyme is added, the rate of reaction increase because it fastens the reactions.
But when the substrate is converted into a product and there is no substrate left to combine with enzyme the rate of reaction stop increasing.
Thus, The rate of reaction stops increasing because there is no substrate left to bound with an enzyme to increase the rate of reaction.
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Final answer:
The reaction rate stops increasing due to enzyme saturation, where all enzyme active sites are fully occupied and cannot bind additional substrates, causing the rate to level off despite more enzyme being added.
Explanation:
The reason the reaction rate stops increasing even with the addition of more enzyme is due to enzyme saturation. At a certain point, all active sites of the enzyme molecules are occupied by the substrate, and they are unable to bind to any additional substrate molecules until the existing substrate is converted into product and released. This phenomenon is known as enzyme saturation, and it explains why the reaction rate levels off. It indicates that the enzymes are working at their maximum capacity, and any further increase in substrate concentration cannot enhance the reaction rate any further.
Research by Yu and Fu (2011) found that approximately _____% of dreams are reported to involve sexual activity.
Answer: 12 per cent
Explanation:
The REM sleep is associated with the prolonged erections males and pelvic thrusting in the females.
It is not being pursued for further studies as a concern of the function of REM sleep. The Yu and Fu found that the sleep involves the dreams about sexual activity.
The desires and fantasy of the real life appears to be complete in the dreams and 12 per cent of the total population see these dreams.
The specified study by Yu and Fu (2011) does not provide an exact percentage of dreams that involve sexual activity. The frequency of such dreams varies greatly among individuals, influenced by factors like age, hormones, and personal experiences. It's universally agreed upon that sexual dreams are normal.
Explanation:Unfortunately, the study by Yu and Fu (2011) does not provide a specific percentage for how many dreams are reported to involve sexual activity.
It's important to note that the frequency of sexual dreams can vary significantly from one individual to another, and can be influenced by various factors such as age, hormonal levels, and personal experiences. Some estimates suggest that about 8% of dreams may have some sexual content, but this is not a consistent figure across all individuals and studies.
However, it is universally accepted that sexual dreams are a normal part of the human dreaming experience.
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A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants.What is the estimated frequency of allele A in the gene pool? A) 0.25 B) 0.50 C) 0.75
Answer:
A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants.What is the estimated frequency of allele A in the gene pool?
0.75
Explanation:
From the above analogy, it is expedient to know that the homozygous recessive with 25% reflects that the heterozygous dominant carries the 75% of the traits i.e 1:3 respectively
In the United States today, about half of the corn crop is genetically engineered with a protein that is toxic to corn borers, an insect pest of corn. Which of the following conditions would be necessary for evolution of resistance to the toxic protein to occur in the corn borer?
A. The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein.
B. The resistant corn borers must survive better or reproduce more than non-resistant corn borers.
C. The corn borers must experience unlimited success in their ability to survive or reproduce.
D. The corn borers must experience no success in their ability to survive or reproduce.
E. The corn borer must lack variation in resistance to the toxic protein.
Answer:
a. The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein.
b. The resistant corn borers must survive better or reproduce more than nonresistant corn borers.
Explanation:
When there is a change in the surroundings of organisms, some genetic variations become beneficial to the organisms. Natural selection favors the organisms having these genetic variations.
The development of resistance in the corn borer population requires the presence of the gene for the resistance in the population. If there is no gene already present in the population, there should be a mutation to give rise to such gene/s. The corn borers having this gene should be able to survive better in the presence of the toxic protein and should leave more progeny in order to increase the frequency of the gene in the population over the generations.
Final answer:
The conditions necessary for evolution of resistance to a) the toxic protein in corn borers are heritable variation in resistance and differential survival or b) reproductive success of the resistant individuals compared to non-resistant ones.
Explanation:
In the context of genetically modified organisms (GMOs) and pest resistance, the evolution of resistance to a toxic protein in corn borers would require the following conditions:
The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein.
The resistant corn borers must survive better or reproduce more than non-resistant corn borers.
These conditions align with the principles of natural selection, where genetic variation and differential survival or reproductive success lead to the evolution of certain traits within a population. The specific statements A and B in the student's question are necessary for resistance to evolve in the corn borer population exposed to genetically engineered corn expressing Bt toxin. However, condition C is not necessary as success in survival or reproduction need not be unlimited; it only has to be greater in resistant individuals compared to non-resistant ones. Condition D would actually prevent the evolution of resistance, and condition E lacks the required variation for natural selection to occur.