Answer:
True
Explanation:
One of the edocrine processes the kidney is involved in is called the RAAS (Renin-Angiotensin-Aldosterone System) which is a signaling pathway involved in blood pressure control. It involves a number of hormones:
Angiotensinogen is produced by the liver in response tovarious inflammatory proteins
Renin is a protease produced by the kidneys in response tohypotension,
Angiotensin II increases blood pressure via a number of mechanisms:
Aldosterone acts to increase reabsorption of Na+ and water and increase elimination of K+ and H+ in the distal tubules of the kidneys for ion concentration maintenance
If whales evolved from land-dwelling mammals, one would expect the fossil record to include intermediate forms, creatures more whale-like than land-dwelling mammals yet still possessing hind limbs and a pelvis lacking in modern whales. Such intermediates are termed __________transitional forms
vestigial features
hybrids
homologous structures
Answer:
transitional forms
Explanation:
the form of organism that exhibit the shape which is intermediate between the their ancestors and the descendants (just like a father between grandfather and grandson) is known to be the transitional form of respective organism.
The transitional form organisms or fossils have some traits and similarities which are common to both ancestors and the descendants.
Judith is receiving messages in her brain from baroreceptors in her stomach, from chemoreceptors detecting PO2 levels in her blood, and from tactile receptors in her skin. All this information must be transmitted in what format in order to be detected by the central nervous system (CNS)?
a. perceptionb. sensationsc. action potentialsd. pain
Answer:
Action potentials.
Explanation:
Receptors are present in the body surface that helps in the detection of the changing inside and outside environment of the body. Different receptors are sensory receptors, baroreceptors and chemoreceptors.
Action potential is the transmission of nerve impulse that occur due to the change in the electric potential of the cell. The information from the baroreceptors occurs by the propagation of the action potential.
Thus, the correct answer is option (c).
In terms of signaling, what is most significant about action potentials?
a) The number of partial action potentials
b) The number of phases
c) The frequency
d) The magnitude Submit
Answer
b) the number of phases
Explanation:
Action potentials cannot be partial.The frequency of signaling is constant. The magnitude it constant as well.Answer:
Letter C
Explanation:
Action potentials are certainly a key to understand neuronal signaling, and to this day, neuroscientists are still developing specific models to try decipher how much information a bunch of neuronal spikes has to inform in distinct neurons.
Interestingly, throughout evolution action potentials have proven to be a very efficient mechanism of communication, and their most studied and most important attribute has been proved to be frequency, which is a property that depends on the source only, ie it does not change until you reach your destination. So, the right answer is Letter C.
Marfan syndrome is the result of inheriting a single allele. Individuals with Marfan syndrome are tall and long-limbed, and have both cardiovascular and eye defects. Of what type of inheritance is the phenotype of Marfan syndrome an example?
A) incomplete dominance
B) pleiotropy
C) codominance
D) a recessive disorder
E) gene linkage
Answer:
Pleiotropy
Explanation:
Marfan syndrome has several signs and symptoms depending on the individual affected.
The main manifestations of the disease are related to the skeletal system, in which the affected individual presents with elongated limbs, elevated height, scoliosis and thoracic deformations; the cardiac system, characterized by mitral valve prolapse (closing of the upper and lower chambers of the left side of the heart) and dilation of the aorta; and the ocular system, characterized by a detachment in the lens of the eye, and myopia.
The ability of genetic defects such as Marfan syndrome to reach such distinct organs is called pleiotropy.
Answer:
Pleiotropy
Explanation:
Pleiotropy is a genetic situation in which a single gene influences or controls the expression of several phenotypes. Consequently, any change that happens to pleiotropic genes always affect multiple characters on the respective organisms.
From the information available, it is obvious that the gene for Marfan syndrome affects the limb, the cardiovascular system and the eye of subjects. Hence, Marfan syndrome gene is a pleiotropic gene.
The correct option is B.
If a plant that is heterozygous for all three characters is allowed to self-fertilize, what proportion of the offspring would you expect to be homozygous for the three dominant traits? Express your answer as a fraction using the slash symbol and no spaces (for example, 1/16).
Answer:
1/64
Explanation:
This cross is a trihybrid cross because it involves three genes. The cross is said to be a self-fertilization of plant heterozygous for the three traits i.e. two plants which have a combination of dominant and recessive alleles for each trait is crossed.
Let's say the three genes involved are genes P, Q and R. Where P, Q and R alleles are dominant over p, q and r alleles respectively. Thus, a heterozygous plant will possess PpQqRr genotype.
In concordance with Mendel's law of independent assortment, the alleles get sorted into gametes independently of one another. Meiosis occurs and each heterozygous plant (PpQqRr) produces 8 possible combinations of gametes viz; PQR, PQr, PqR, Pqr, pQR, pQr, pqR and pqr.
These gametes are crossed using a punnet square (see attached image) to produce a total of 64 possible offsprings i.e. 8 (male gametes) × 8 (female gametes).
A phenotypic ratio of 27:9:9:9:3:3:3:1 will result from a trihybrid cross involving two species heterozygous for the three genes/traits. (Check attached image for details of their phenotype)
According to the question, the fraction of offsprings expected to be homozygous dominant for the three traits is 1 out of 64 possible offsprings = 1/64
Note that, homozygous dominance is a state where the alleles for each gene are the same type i.e PPQQRR. Since P, Q and R are the dominant alleles.
Although 27 of the 64 offsprings are dominant for each trait but only one is homozygous dominant (PPQQRR) for the three traits, the other 26 are dominant but had one or more recessive genes i.e. are heterozygous for some/all genes
Final answer:
The proportion of offspring from a heterozygous plant self-fertilization that are homozygous for three dominant traits is 1/64.
Explanation:
If a plant that is heterozygous for all three characters is allowed to self-fertilize, the proportion of the offspring expected to be homozygous for the three dominant traits is found by considering each trait independently. Using the product rule for independent assortment, the probability for each trait to be homozygous dominant is 1/4 (since for a single trait, there is a 1:2:1 ratio for YY:Yy:yy genotypes). With three traits, this is (1/4) × (1/4) × (1/4), which equals 1/64. Therefore, the fraction of offspring that are homozygous dominant for all three traits is 1/64.
The kidneys function based on the movement of fluids across the filtration membrane. There are three different types pressure operating at the filtration membrane. List and explain how each influences net filtration pressure.
Answer:
The major force that tends to create a push for the water and solvent to the filtration membrane is Glomerular hydrostatic pressure (GHP). The other pressures are Capsular hydrostatic pressure and Net filtration pressure.Explanation:
Glomerular osmotic pressure: creates pressure in the glomerular blood for the plasma protein to enter filtration membrane.Capsular hydrostatic pressure: it brings back the fluids into the glomerular capillaries. In mathematical term the net filtration can be sated as: Net filtration pressure = glomerular hydrostatic pressure - glomerular osmotic pressure + capsular hydrostatic pressure.Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.
A) hormones alter cellular operations through direct stimulation of a gene
B) peptide hormones are converted by cell membranes enzymes into second messengers
C) G protein acts as the link between first and second messengers
D) the hormone receptor complex moves into the cytoplasm as a unit
Answer:
Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because C) G protein acts as the link between first and second messengers .
Explanation:
When the first messengers join the receptor, in the external membrane of the cell, it produces a change in the shape of the receptor that causes the join of the G protein to this structure. The G protein joined to the receptor and the first messenger modulates the activity of the second messengers inside the cell.
Which conditions occurs when the bronchial tubes are inflamed and
Answer:
The answer is bronchitis. There is two types acute and chronic.
Explanation:
It causes a cough that often brings up mucus. It can also cause shortness of breath, wheezing, low fever, chest tightness.
One strand of a DNA molecule has the following sequence: 3-AGTACAAACTATCCACCGTC-5. In order for transcription to occur in that strand, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated.
Answer: Promoter
Explanation:
Transcription is the first step in gene expression which consists of copying the DNA sequence of a gene to produce a RNA molecule. There are enzymes called RNA polymerases which perform this process of transcription. These enzymes bind nucleotides (the monomers which are part of the nucleic acids) to create a RNA strand using a DNA strand as a mold.
A promoter is a region of DNA that controls the initiation of transcription of a given portion of DNA to RNA. Therefore they promote the transcription of a gene. The promoter region is composed of a specific sequence of DNA located just where the starting point of the DNA transcription is and contains the information needed to activate or deactivate the gene it regulates. The promoter has a binding site for the RNA polymerase enzyme in charge of mRNA synthesis and when it recognizes this site, transcription begins.
Final answer:
The recognition sequence needed for transcription to start is known as a promoter. For the given DNA sequence, the complementary strand would be constructed based on pairing rules: adenine with thymine and guanine with cytosine, resulting in the sequence 5'-TCATGTTTGATAGGTGGCAG-3'. This is important for understanding transcription and the subsequent synthesis of mRNA.
Explanation:
The student's inquiry relates to the transcription process of DNA into RNA, specifically involving the initiation of transcription. The specific recognition sequence mentioned in the question, typically found upstream (to the left considering the conventional 5' to 3' directionality) of the coding region of a DNA strand, is known as a promoter. Transcription factors and RNA polymerase bind to this promoter sequence to initiate transcription.
For the given DNA sequence 3'-AGTACAAACTATCCACCGTC-5', the corresponding sequence on the opposite, or complementary, strand, oriented in the conventional 5'-3' direction, would pair adenine (A) with thymine (T), guanine (G) with cytosine (C), and vice versa to form the complementary strand. Therefore, the complementary strand would be 5'-TCATGTTTGATAGGTGGCAG-3'. However, it should be noted that for transcription purposes, the actual molecule synthesized is messenger RNA (mRNA), which uses uracil (U) instead of thymine (T).
A nurse is teaching a family how to best help their child who has been recently diagnosed with a neurodevelopmental disorder. Which statement indicates to the nurse that teaching has been effective?
Answer:
The correct answer would be - "we will be able to enjoy more structure in our house".
Explanation:
Neurodevelopmental disorder case of a children need structure, short tasks to be more functional. It is tough and not able to do well as the children with neurodevelopment disorder can not be sit still for longer period of time and are not easily adapt any type of change in routine. So going out in crowded places or bus rides may be tough to accomplish.
Noises places are also be tough with such children so the nurses teaches the parents to perform instructed tasks and structures to keep them functional as such kids have disruptive behaviors and lack of focus.
Thus, the correct answer is - "we will be able to enjoy more structure in our house".
How are rna hairpin turns related to transcriptional termination in e. Coli?
Answer:
The answer is the turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase.
Explanation:
The turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase.
While playing soccer in your backyard, you disrupt a small fire ant mound. The fire ants emerge and bite your feet. Your feet begin to show swollen, raised areas around the bites. What is happening?
Answer: Your innate internal defenses have been activated.
Explanation:
The ant bite the feet of the child and the ants released some chemicals(venom) in the body of the child.
This is recognized by the immune system of the body and the innate defense in the body starts.
Serious reactions takes place in the body in response to the ant bite. It is more common in the children as compared to that of adults.
Some characteristics of DNA are shared between all living organisms, whereas other characteristics of DNA differ between organisms. Classify DNA characteristics as either being a universal attribute of DNA or an attribute of DNA that is unique to particular individuals or species.nucleotides A,C,G,T; triplet; DNA sequence; size of genome;code for amino acids.
Answer:
Universal DNA attribute: nucleotides A,C,G,T; triplet; code for amino acids.
DNA attribute unique to particular individual: DNA sequence; size of genome.
Explanation:
As all the organisms on the earth are evolved from a single organism or individual, therefore, all the organism on the earth share some universal attributes like nucleotide that are used to make DNA are same in all the individuals as all use A, T, G, C nucleotide to make DNA.
Triplet codon for a particular amino acid is also universal so a triplet codon UUU codes for phenylalanine in all the individual present on earth. Due to evolution organisms generated some difference in their genome like genome sequence in almost every individual is different and genome size also differ between organisms. So DNA sequence and size of the genome are unique to a particular individual.
If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signaling is occurring?A) autocrineB) paracrineC) endocrineD) neuroendocrine
Answer:
The correct answer will be option-C
Explanation:
The pancreas is a small pear-shaped gland present in the abdomen and surrounded by the stomach. The pancreas acts as both endocrine (secretes glucagon and insulin hormones) and exocrine (secretes digestive enzymes).
In the given question, the pancreatic part removed from the rat results in the loss of appetite as when insulin is not produced in the body results in uncontrolled sugar levels in the body. This leads to the loss of water from the body to the urine and as a result, the loss of appetite is observed.
Since the endocrine portion controls the insulin production therefore, option-endocrine is the correct answer.
Can I have help with question #32?
Thanks!
Answer:
Proteins synthesized in the ER are packaged into vesicles, which then fuse with the Golgi apparatus. These cargo proteins are modified and destined for secretion via exocytosis or for use in the cell.
Explanation:
Answer:Cool thanks
Explanation:djdhbd
What is a microorganism [a microbe] that is innocuous [not harmful] to man or to a given animal species? It is a living being which does not possess the capacity to multiply in our body or in the body of the animal. But nothing proves that if the same microorganism should chance to come into contact with some other of the thousands of animal species in the Creation, it might invade it and render it sick. Its virulence might increase by repeated passages through that species, and might eventually affect man or domesticated animals." —Louis Pasteur Which of the following statements is a reasonable inference to draw from this quote by Louis Pasteur?
Answer:
The correct answer will be- a microorganism can mutate or change with time and can become virulent.
Explanation:
If a bacteria is considered harmless or avirulent then the bacteria will not necessarily affect the animal species.
But when the species come into contact with other sick species caused by the microbe will make the bacteria virulent. This shows that bacteria can change with time depending on the environment it is living in.
Thus in the given question, bacteria can change and mutate with time and can become virulent from avirulent species.
Final answer:
A harmless microorganism in one species may become harmful if it adapts to a new species, suggesting the dynamic nature of microbial-host interactions.
Explanation:
From the quote by Louis Pasteur, a reasonable inference is that microorganisms which are harmless in humans or a specific animal species could potentially become harmful if they come into contact and adapt to other species. The process of adaptation and increasing virulence in a new host species can potentially lead to new diseases affecting humans or domesticated animals.
This highlights the dynamic nature of microbial-host interactions and the potential for previously innocuous microbes to evolve and pose threats to health.
Stimulation of muscle fibers at a rate of 20 to 40 stimuli per second does not allow for complete relaxation of the fibers before the next stimulatory event. This results in _________ and can lead to incomplete tetany.
Answer:
Tetanic spasms/ tetanic contractions
Explanation:
Tetanic spasms occurs when a muscle has a sustained contraction because of an increase in action potential in skeletal muscles
Incomplete tetanus occurs when muscle fibers are stimulated at a rate that does not allow for complete relaxation between stimuli.
Explanation:In biology, the phenomenon described in the question is known as incomplete tetanus. Incomplete tetanus occurs when muscle fibers are stimulated at a rate that does not allow for complete relaxation between stimuli. This leads to sustained, but not maximal, muscle contractions.
For example, if muscle fibers are stimulated at a rate of 30 stimuli per second, there is not enough time for the muscle to fully relax between each stimulus. As a result, the muscle remains partially contracted, leading to incomplete tetanus.
This phenomenon can be observed in the body during activities that require sustained muscle contractions, such as gripping objects tightly or maintaining a constant posture for a long period of time.
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There are nearly 30 different disorders of sexual development. Who can have these disorders? There are nearly 30 different disorders of sexual development. Who can have these disorders? people with neither XX nor XY chromosomes only people with XY chromosomes only people with XX chromosomes people with either XX or XY chromosomes
Answer:
The answer is people with either XX or XY chromosomes
Explanation:
People with either XX or XY chromosomes
Biochemical, evolutionary, and genetic evidence of functionality can help identify single nucleotide polymorphisms (SNPs) that are important in controlling gene expression or contributing to disease progression. True or False?
Answer:
True
Explanation:
Polymorphism is a phenomenon that arises when proteins, DNA and RNA can appear with different molecular forms. Polymorphism is characterized as single nucleotide polymorphism when molecular variation occurred in only one nitrogenous DNA base, thus causing genetic variation in a population. This type of polymorphism is very important to regulate the gene expression of individuals and to measure the progression of a disease. This requires that the unique nucleotide polymorphism be identified. This identification occurs through biochemical, evolutionary and genetic evidence.
While looking at some seawater through your microscope, you spot the egg of an unknown animal. Which of the following tests could you use to determine whether the developing organism is a protostome or a deuterostome? See whether the embryo _____.A) exhibits spiral cleavage or radial cleavageB) develops a blastoporeC) develops germ layersD) develops an archenteron
Answer:
The correct answer will be option- A
Explanation:
The protostomes and deuterostomes are the classification of the animal kingdom based on the stages of embryological development.
In protostomes, the mouth develops from the opening called blastopore side whereas anus develops secondarily whereas, in the deuterostomes, the anus develops from the blastopore while the mouth develops secondarily.
This difference begins as a result of the cleavage pattern formed during the initial stages of the embryo that is in protostomes the cleavage pattern is spiral whereas in the deuterostomes the cleavage pattern is radial. In the given question, one should look at their cleavage pattern and can classify the egg
Therefore, option-A is the correct answer.
To determine if the developing organism is a protostome or a deuterostome, you can observe the type of early cleavage that occurs. Protostomes exhibit spiral cleavage, while deuterostomes undergo radial cleavage.
Explanation:The test you could use to determine whether the developing organism is a protostome or a deuterostome is to observe the type of early cleavage that occurs. Protostomes typically exhibit spiral cleavage, where the cells of one pole of the embryo are rotated and misaligned with respect to the cells of the opposite pole. On the other hand, deuterostomes undergo radial cleavage, where the cleavage axes are either parallel or perpendicular to the polar axis, resulting in the alignment of the cells between the two poles.
Wilona continually encourages her team to work independently from her -- the group leader. She does this by encouraging group cohesion. Wilona is an example of a ________ leader.
a. transformational
b. servant
c. authoritarian
d. charismatic
Wilona continually encourages her team to work independently from her, the group leader. She does this by encouraging group cohesion. Wilona is an example of a transformational leader, which is option A.
What is a transformational leader?Wilona, who encourages her team to work independently of her, is an example of a transformational leader. Transformational leaders are those who inspire and motivate their followers to achieve extraordinary outcomes and surpass their personal goals. They focus on building relationships, team cohesion, and a vision that resonates with their followers. In this case, Wilona is promoting group cohesion and empowering her team to work independently, which is a characteristic of a transformational leader.
Hence, Wilona continually encourages her team to work independently from her, the group leader. She does this by encouraging group cohesion. Wilona is an example of a transformational leader, which is option A.
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Positive feedback differs from negative feedback in that:
A. positive feedback benefits the organism, whereas negative feedback is detrimental.
B. the positive feedback's responses are in the same direction as the initiating stimulus, rather than opposite to it.
C. positive feedback results in increases in some parameter (such as body temperature), whereas negative feedback results only in decreases to the parameter.
D. positive feedback systems have control centers that are lacking in negative feedback systems.
Answer:
C. Positive feedback results in increases in some parameter (such as body temperature), whereas negative feedback results only in decreases to the paramenter
Explanation:
Positive and negative feedback are essential to the body's homeostasis, or to maintain balance and regulate the internal environment of organisms; that is to say, they are important for the organisms to self-regulate themselves. Positive feedback is in the same direction as the initiating stimulus as they amplify the original stimulus. Positive feedback leads to an increase in a reaction, thus amplifying the effects of a reaction. However, negative feedback decreases a reaction; negative feedback stabilizes the system.
Positive feedback enhances or amplifies the initial stimulus, while negative feedback seeks to bring the system back to its normal state after a change. This thus differentiates the two in terms of system response, rather than benefits to the organism.
Explanation:The major difference between positive feedback and negative feedback is the way they respond to changes in the system. Option B is correct.
In Positive feedback, the response enhances or amplifies the initial stimulus. For instance, during childbirth, the release of oxytocin enhances contractions, which is an example of a positive feedback loop.
In contrast, negative feedback aims to maintain homeostasis by bringing the system back to its normal state after a change. For example, when body temperature rises, sweat is produced to cool the body, bringing the temperature back to normal.
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When you are injured and bleeding the clotting factors immediately start to clot and try to seal the wound. This would be an example of ________________________________ level of regulation.
Explanation:
This would be an example of secondary homeostasis
During wound healing, which happens after bleeding from a cut, the homeostatic response is clotting; primary homeostasis involves the formation of a platelet plug at the site, from platelets within the blood
Fibrinogen and platelets form a clot, in order to prevent blood loss and infection. Fibrin is formed through the activation of coagulation factors which stabilise the plug.
Further Explanation:
The nervous system is subdivided into; the central nervous system (CNS), which includes the brain and spinal cord, within the vertebral column; and the peripheral nervous system, which includes nerves that branch into the rest of the body from the brain and spinal cord. Nervous tissue responds to electrical impulses, allowing for communication between different regions of the body.
The peripheral nervous system is further divided into the somatic nervous system responsible for carrying out sensory and motor information between the peripheral nervous system- including sensory organs like the eyes; and central nervous system; and the autonomic nervous system (ANS) which regulates involuntary bodily functions like heartbeat, breathing and blood flow. The ANS is mainly acts unconsciously and affects smooth muscle and internal organs. It is related to homeostasis- where the body maintains a constant internal balance in pH, temperature, blood pressure etc.
During homeostasis the body maintains a constant internal balance in pH, temperature, blood pressure etc. Cells in a multicellular organism become specialized for particular tasks and communicate with one another in order to maintain homeostasis. Within the human body these are known as hormone cascades, where several complex steps occur- the tissues signal to one another with the use of hormones released by the endocrine system. The regulation (increase and decrease) of these secretions is achieved by negative feedback loops, where the release of certain substances during a cascade in turn halts the secretion of hormones at earlier stages.
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Color in squash is controlled by epistatic interactions in which color is recessive to no color. At the first locus white squash (W) is dominant to colored squash (w). At the second locus yellow (Y) is dominant to green (y). What is the phenotype of a squash with the genotype wwYy?
a) white
b) green with yellow strips
c) green
d) yellow
e) white with yellow strips
Answer: yellow
Explanation:
Phenotype refers to the observable physical properties of an organism. phenotype is determined by its genotype. Phenotype is a description of your ones physical characteristics.
From the question, the first locus which is a white squash (W) is dominant to colored squash (w) and the second locus yellow (Y) is dominant to green (y).
ww(that is; the coloured squash) are not dominant while y (that is the green) is also not dominant but only the Y(that is ; the YELLOW squash) is DOMINANT.
Therefore, the phenotype of the squash will be Yellow.
The ABO blood type locus has been mapped on chromosome 9. A father who has type AB blood and a mother who has type O blood have a child with trisomy 9 and type A blood. Using this information, can you tell in which parent the nondisjunction occurred? explain your answer.
Answer:
From this information we can tell that the nondisjunction occurred in the motherExplanation:
Blood group is controlled by 3 allele (Ia, Ib and i). So the following results are possible
Iai - Type A IaIb - type AB (Ia and Ib are codominant over each other and dominant over allele i) Ibi - type B ii - type O (allele i is recessive)
So if non-disjunction had occurred in father then his gametes would contain both Ia and Ib, which when fertilized with ovum having i allele would result in IaIbi which will have blood type AB.
Non-disjunction in female would produce ovum having 2 copies of allele i (or ovum having ii). And gametes of normal male will have Ia and Ib. So if this abnormal ovum (having ii) fertilized with male gamete having allele Ia then zygote will have genotype of Iaii which will be blood type A.
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A group of nursing students are reviewing information about penicillins. The students demonstrate understanding of the information when they identify the action of penicillinase as causing bacterial resistance by which mechanism?
A. destruction of the beta-lactam ring of the penicillin
B. destruction of the penicillin cell wall
C. rupture of the penicillin membrane
D. enzymatic inactivation of the penicillin
Answer:
A. destruction of the beta-lactam ring of the penicillin
Explanation:
Penicillins and other antibiotics in the beta-lactan family usually contain a characteristic four-membered ring of beta-lactam.
A penicillin is capable of killing bacteria by binding β-lactam to DD-transpeptidase (a bacterial enzyme that binds peptidoglycan chains to form rigid moving cell walls), inhibiting its activity and preventing the formation of a new cell wall.
Without a cell wall, bacterial cells become vulnerable to external water and molecular pressures, and thus die quickly.
Bacteria can generate resistance to penicillin by producing beta-lactamase, a bacterial enzyme that destroys the penicillin beta-lactan ring, rendering it ineffective.
An example of penicillin-resistant bacteria is Staphylococcus aureus, which produces high amounts of β-lactamase. This bacterium can cause skin, blood or lung infections.
Penicillinase causes bacterial resistant by hydrolyzing and breaking the beta-lactam ring of penicillin, which inactivates the antibiotic and prevents it from inhibiting bacterial cell wall synthesis.
Explanation:The action of penicillinase, which causes bacterial resistance, is best described as the destruction of the beta-lactam ring of the penicillin. Penicillinase is a type of beta-lactamase enzyme that bacteria produce to defend against penicillin-class antibiotics. This enzyme targets the crucial beta-lactam ring structure within the penicillin molecule, breaking it open and thus inactivating the antibiotic. Inactivation of the drug occurs through hydrolysis of the beta-lactam ring, which is essential for the drug's bactericidal activity, as it prevents the synthesis of bacterial cell walls.
Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane?
a. receptor tyrosine kinase
b. G protein-coupled receptor
c. ligand-gated ion channel
d. intracellular receptor
Answer:
c. ligand-gated ion channel
Explanation:
As soon as a signaling molecule binds a ligand-gated ion channel it leads to the opening of these ion channels which in turn causes ions to either rush inside or outside of the cell on which they are located leading to the disruption of distribution of initial ion concentration.
As the name suggests, these kind of receptors are also known as ionotropic receptors.
For example: Binding of acetylcholine hormone to it's receptor which is a ligand gated cation channel located at post synaptic muscle cells leads to the opening of Na⁺ ion channels. As a result of this, Na⁺ rushes into muscle cell leading to the change in the concentration of Na⁺ inside the muscle cells. This is known as depolarisation.
Ravi ran 200 metres race in sports day. He feels that his heart was beating faster than usual. a) Why was his heart beating faster? b) Which all organs are involved along with the heart to help Ravi complete his race?
(a) Reason for the heart beating fast:
When we exercise/run the muscles work hard and need more oxygen. So, when Ravi's heart beats faster more blood can be pumped to the muscles thus giving the oxygen required.(b) Organs involved along with the heart to help Ravi complete his race:
The main organs involved along with the heart are quadriceps, hip flexors, hamstring, glutes and calf muscles. The nervous system, muscular system, skeletal system, respiratory system and circulatory system function effectively when a person runs.Some mutagens cause genetic changes that can be "corrected" by re-exposing cells to the same mutagen. Other mutagens do not behave in this way. Provide one example of each of these two types of agents and describe the mutational changes caused in DNA. Explain why some mutagens behave in one way, while others do not.
Answer:
Explanation:
Mutagen:
It's any agent that can cause changes to the a cell genetic makeup by altering the deoxyribonucleic acid (DNA)
It can be a Physical mutagens (e.g X-rays), chemical mutagens e.g Nitrous acid or biological mutagens as in transposons
Examples of mutagens that cause genetic changes that can be "corrected" by re-exposing cells to the same mutagen are the ones that caused base substitutions (e.g nitrous acid) and Frameshift mutations (e.g proflavin)
A mutagen that do not cause genetic changes like deletion that can be "corrected" Such as by re-exposing cells to the same mutagen is the X rays.
Some mutagens cause genetic changes that can be 'corrected' by re-exposing cells to the same mutagen, such as UV radiation and thymine dimers. Other mutagens, like chemicals inhaled while smoking, cause mutations that cannot be 'corrected' by re-exposure.
Explanation:Mutagens are agents that cause mutations in DNA. Some mutagens cause genetic changes that can be 'corrected' by re-exposing cells to the same mutagen. An example of this type of mutagen is UV radiation, which can cause the formation of thymine dimers in DNA. If not repaired, the dimers can prevent the formation of the double helix. However, cells have DNA repair mechanisms that can recognize and repair thymine dimers.
On the other hand, some mutagens do not behave in this way. For example, chemicals like those inhaled while smoking can modify the bases in DNA, changing their base-pairing properties. These modifications can lead to mutations that cannot be 'corrected' by re-exposure to the same mutagen.
To synthesize DNA, what does telomerase use as a template?A. It uses RNA that is already a component of telomerase.B. It uses the 3' OH of an RNA primer on the opposite strand of DNA.C. It uses the DNA in the 3' overhang of the DNA.D. It uses RNA in the 3' overhang of the DNA.E. Telomerase does not synthesize DNA.
Answer:
The correct answer is A. It uses RNA that is already a component of telomerase.
Explanation:
When DNA is synthesized, a part of each end is lost. So, therefore, the telomerase uses an RNA that's already part of the enzyme, so the lost information won't be missing in the new DNA.
Telomerase uses its inherent RNA component as a template to synthesize DNA, extending telomeres and maintaining chromosome integrity.
Explanation:To synthesize DNA, telomerase uses an RNA template that is already a component of the enzyme. Specifically, this RNA template is referred to as telomerase RNA (TR) or TERC (TElomere RNA Component), which includes a segment that provides the template for the addition of telomere repeats to the ends of chromosomes. The enzyme tacks on several sequences of DNA nucleotides that complement the RNA template. The process is mediated by the enzyme's protein component known as TERT (TElomere Reverse Transcriptase), which acts as a reverse transcriptase, synthesizing DNA based on the RNA template provided by the telomerase itself.