Answer:
ATP molecules
Explanation:
Density centrifugation is a method that separates components of a sample on the basis of their density or density gradient.
During centrifugation the sample will be layered according to their density and that is the principle of density centrifugation.
When centrifuging a sample containing homogenized cells. ATP molecules will be found at the top of the centrifugation gradient due to having a lighter density compared to the rest of the molecules.
In psychology, ________ is a set of statements about the mechanisms underlying a particular behavior, is a hypothetical mechanism used to help explain behavior, and is a way to measure an observable characteristic that serves as a stand-in for something that is not observable.
Answer:
Theory
Explanation:
The theory is referred to the set of documents that are provided for the better understanding of the human emotion, rights, thoughts, and behaviors.
Theory work for two main aspects -
- it must provide or analyze the behaviors
- it must induce hypothesis and predict future behaviors
A theory is a document that gives an explanation about an understanding of the facts. it includes question like why and so. it is a series of documents that present on the wider scale to have been accepted by larger communities.
Final answer:
In psychology, a theory is a well-developed set of ideas that propose an explanation for observed phenomena and includes measurements to test the effects of behaviors. Experiments are used to test hypotheses and determine cause and effect relationships. Hypotheses are tentative explanations for observations that can be scientifically tested.
Explanation:
In psychology, a theory is a set of statements about the mechanisms underlying a particular behavior. It is a hypothetical mechanism used to help explain behavior, and it involves a way to measure an observable characteristic that serves as a stand-in for something that is not observable. This measurement assists in the measurement of the effect that an experience might have.
Psychologists use various research methods to understand and explain behavior and the cognitive and biological processes that underlie it. Methods can include observational techniques, in-depth interviews, and experiments, which are designed to test hypotheses in a controlled setting. These experiments are the only research method that measures cause and effect relationships between variables, aiming to explain how certain factors or events produce outcomes.
The hypothesis in psychological research is a tentative explanation for scientific observations that can be framed in a way that is testable. This is critical as it contributes to the validity, which revolves around the accuracy of a given result in measuring what it is designed to measure. Explaining causal relationships and the mechanisms by which they are mediated can be extrapolated to predict and explain events in new contexts.
Contraction of the diaphragm and external intercostal muscles results in ____________ in the thoracic volume which results in _______________ of the intrapulmonary pressure.
Answer:
Contraction of the diaphragm results in increase in thoracic volume which results in decrease of the intrapulmonary pressure.
Explanation:
During inspiration, air is taken into the lungs this requires that the diaphragm contracts to increase the volume of the thoracic cavity while intrapulmonary pressure decreases to allow intake of air.
Contraction of the diaphragm and external intercostal muscles leads to an increase in the thoracic volume, which in accordance with Boyle's Law, results in a decrease of intrapulmonary pressure.
Explanation:When the diaphragm and external intercostal muscles contract, it results in an increase in the thoracic volume. This increase in volume causes a decrease in the intrapulmonary pressure.
This is because, according to Boyle’s Law, the pressure of a gas is inversely proportional to its volume. In this context, when the volume of the thoracic cavity increases (during inhalation), the pressure within it decreases, which draws air into the lungs.
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The nucleoid region of a prokaryotic cell
A. contains the cell's DNA
B. separates the RNA from the cytoplasm
C. is surrounded by a nucleoid membrane
D. contains the cell's nucleoid membrane
E. is the site of organelle production
Answer:
A. contains the cell's DNA
Explanation:
Prokaryotic cells such as the bacterial cells and the cells of archaeans do not have a membrane-bound nucleus. Their genetic material DNA is present in the cytoplasm only. However, their genetic material is concentrated in a specific region inside their cells. This is called a nucleoid. Nucleoid does not have any surrounding membrane. It represents the nuclear area where the DNA of the prokaryotic cells is present.
The nucleoid region in a prokaryotic cell primarily contains the cell's DNA and does not have a distinct membrane, separate RNA, or produce organelles.
Explanation:The nucleoid region of a prokaryotic cell primary function is to house the cell's DNA. Prokaryotic cells do not have a true nucleus or other membrane-bound organelles. Therefore, option A. 'contains the cell's DNA' is correct. Instead, their genetic material is located within a region called the nucleoid. This region is not surrounded by a nucleoid membrane as it would be in eukaryotic cells (disqualifying options C and D). It is also not specifically involved in separating RNA from the cytoplasm or in the production of organelles (eliminating options B and E).
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Monomeric proteins do not have a. primary structure b. secondary structure c. tertiary structure d. quaternary structure
Answer: Quaternary structure
Explanation:
The proteins exists in all the structures such as primary, secondary and tertiary. The primary structure of the protein is simple, secondary is made of two sheets like structure.
The tertiary structure of the proteins is made of beta pleated structure. The monomeric proteins do not form quaternary structure. It is reserved for proteins having two or more polypeptide chains.
Hence the correct answer is Option D
Monomeric proteins lack a quaternary structure; this level of structure refers to the assembly of multiple polypeptide chains into a functional protein complex. Monomeric proteins only possess primary, secondary, and tertiary structures.
Explanation:Monomeric proteins do not have a quaternary structure. A quaternary structure is formed only when multiple polypeptide chains, also known as subunits, come together to form a functional protein complex. Monomeric proteins, composed of a single polypeptide chain, include only the primary, secondary, and tertiary structures. The primary structure is the sequence of amino acids in the polypeptide chain. The secondary structure refers to local configurations such as α-helices and β-sheets within a polypeptide chain, resulting from hydrogen bonding. The tertiary structure represents the overall three-dimensional shape of the protein, which is critical for the protein's function.
Middle ear infections can cause a conductive hearing, a child who experiences this type of impairment is likely to have difficulty hearing:
Answer:
Soft sounds
Explanation:
Conductive hearing loss occurs when the sound waves cannot be transferred in the ear due to the obstruction of any path such as the outer ear, the middle ear or the eardrum.If a person suffers from middle ear infection then the blockage would be in the middle ear and the person would suffer from conductive hearing loss.Due to this hearing loss the sound a person perceives becomes muffled and of softer due to which the sound that is already of lower frequency cannot be heard. Therefore, the child suffering from the given impairment would find it difficult to hear soft sounds.__________ is sometimes used in late first-stage labor and during delivery in order to block sensation in an area of the body or to block consciousness.
Answer:
Epidural anesthesia is sometimes used in late first-stage labor and during delivery in order to block sensation in an area of the body or to block consciousness
Explanation:
Epidural anesthesia blocks pain in a particular region of the body. The reason for epidural anasthesia is to provide analgesia (pain relief) rather than anesthesia (total lack of feeling). Epidurals is a regional anesthesia that works by blocking the nerve impulses from the lower spinal segments.
The correct answer is epidural anesthesia.
Genes: Group of answer choices a) are segments of DNA that code for proteins b) are located on chromosomes c) come in pairs but segregate during the formation of gametes d) assort independently of each other if they are on different chromosomes e) all of the above are true
Answer:
e) all of the above are true
Explanation:
Genes are the stretch of DNA that code for a specific polypeptide chain. Genes are present in linear order on the chromosomes. A diploid organism has two alleles of a gene. The two alleles of a gene separate from each other during the segregation of sister chromatids in anaphase-II of meiosis.
This results in the presence of one allele for each gene in a gamete. Also, the alleles of two different genes segregate in a random way and produce new combinations of genes in the progeny. Random segregation of alleles of two genes occurs when they are present at different chromosomes.
The entrance of a microbe into an individual's vascular space has initiated opsonization. How will the health care provider explain this process that is critical in stopping the infiltration of the microbe through opsonization?A) Stimulation of B cells by helper T cells.B) Coating of microbe to aid phagocyte recognition.C) Release of proteins that stimulate cell production by the bone marrow.D) Lysis of intracellular microbes by cytotoxic T cells.
Answer:
B) Coating of microbe to aid phagocyte recognition
Explanation:
Opsonization is the process and mechanism which targets the foreign body and helps in the recognition of the pathogen by the phagocytic cells such as the macrophages and dendritic cell.
The opsonization enhances the process of phagocytosis as the opsonin substances which could be the antibodies, proteins or other molecules which could be easily recognised by the phagocytic cells gets attached to the pathogen.
Thus, Option-B is the correct answer.
Opsonization is the coating of a particle with proteins that facilitate phagocytosis of the particle by tissue macrophages and activated follicular dendritic cells (FDCs) as well as binding by receptors on peripheral blood cells
A member of the health care team is researching the etiology and pathogenesis of a number of clients who are under his care in a hospital context. Which of the following aspects of clients' situations best characterizes pathogenesis rather than etiology?A. A client who has been exposed to the Mycobacterium tuberculosis bacteriumB. A client who has increasing serum ammonia levels due to liver cirrhosisC. A client who was admitted with the effects of methyl alcohol poisoningD. A client with multiple skeletal injuries secondary to a motor vehicle accident
Answer:
The correct answer is B. A client who has increasing serum ammonia levels due to liver cirrhosis
Explanation:
Etiology is the study of origin or cause of any disease. Pathogenesis is the mechanism of causing disease by any pathogen. Pathogens use four-step to become pathogenic which are contact, colonization, invasion, and infection.
In pathogenesis the symptoms of disease is observed not the cause so in option B increasing serum ammonia level is the symptom of liver cirrhosis which characterize pathogenesis rather than etiology and in other option, only cause of a medical condition is described so the correct answer is B.
The situation that best characterizes pathogenesis is a client with increasing serum ammonia levels due to liver cirrhosis.
Explanation:The term 'etiology' refers to the cause or origin of a disease, while 'pathogenesis' refers to the development and progression of a disease. Out of the given options, the situation that best characterizes pathogenesis is option B - a client who has increasing serum ammonia levels due to liver cirrhosis. In liver cirrhosis, the impaired liver function leads to the accumulation of toxins like ammonia in the blood, resulting in elevated serum ammonia levels.
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What is the abbreviation for a diagnostic procedure in which a small piece of muscle is removed to be sent to the laboratory for examination and analysis?
Answer:
The diagnostic procedure in which a small piece of muscle is removed to be sent to the laboratory for examination and analysis is called as biopsy.
Explanation:
Biopsy is the examination procedure of the tissue of organism by taking small piece of muscle.In order to diagnose the neuro muscular disorder biopsy examination is carried out.Normally biopsy result is obtained in around 2 to 3 days if it is not a complex case.The tissue sample (piece of muscle) is taken in the lab and pathologist take all the tests on it.Answer:
"Muscle Biopsy" is the abbreviation for a diagnostic procedure in which a small piece of muscle is removed to be sent to the laboratory for examination and analysis.
Explanation:
The microscopically or biochemically examination of a piece of muscle tissue which is removed from an organism in medicine is called as "muscle biopsy".
There are basically two major methods for performing this diagnostic procedure: A method in which small amount of tissue is taken out as sample by inserting biopsy needle into a muscle or by open biopsy in which muscle tissue is removed by making a small cut in the skin and muscle.
This procedure is helpful in discovering issues related to musculoskeletal, connective, nervous and vascular systems of body. It is known for detecting polymyositis or dermatomyositis known as inflammatory diseases of muscle and polyarteritis nodosa called as connective tissue and blood vessels diseases.
A scientist compared the genes and proteins from a root cell and a leaf cell of a single apple tree. What will the scientist observe about the cells?
Options:
a) They have different sets of genes but the same set of proteins. (b) They have different sets of genes and different sets of proteins. (c) They have the same set of genes and the same set of proteins. (d) They have the same set of genes but different sets of proteins.
Answer:
d) They have the same set of genes but different sets of proteins
Explanation: Auxins are found in leaves cytokines are found in root tips and shoot tissues.
The enzyme pyruvate kinase catalyzes the conversion of phosphoenolpyruvate to pyruvate; the phosphate group is transferred to ADP to form ATP. This reaction is an example of:
Answer:
Oxidative Phosphorylation in glycolysis.
Explanation:
Kinases are the enzymes which cause transfer of the phosphate group from one molecule to another molecule . As the PEP is converted to pyruvate in glycolysis by a pyruvate kinase enzyme it causes phosphorylation. It is one of the important regulatory steps of glycolysis.
Answer: ATP synthesis by substrate level phosphorylation
Explanation:
The dephosphorylation if phosphoenol pyruvate (PEP) to pyruvate by pyruvate kinase is an example of substrate level phosphorylation where one molecule of ATP is generated during this reaction.
Pyruvate kinase catalyzes the transfer of a phosphate group from PEP to ADP, which produces one molecule of pyruvate and one molecule of ATP. This step is irreversible.
This reaction is an ATP synthesis by substrate-level phosphorylation
A researcher discovers a new prokaryote that lives on the seafloor near hydrothermal vents. This organism reduces CO2 to form C6H12O6, and also derives energy from H2 (by oxidation). This prokaryote is a:A. photoautotroph.B. photoheterotroph.C. chemoheterotroph.D. chemoautotroph.
Answer:
D. Chemoautotrophs
Explanation:
Autotrophs in plain are organisms that synthesize their own food while hetrotrophs are organisms that do not synthesize their own food.
Chemotrophs (Chemoautotrophs and Chemohetrotrophs) are a group of organisms that obtain their energy through the oxidation of inorganic molecules, These organisms require carbon to survive and reproduce.
Chemoautotrophs are able to produce inorganic molecules by the fixation of CO2 from their immediate environment. The energy required for this process is got from Nitrogen, Magnesium, Sulphur etc.
Chemohetrotrophs are a class of chemotrophs that are unable to synthesize their own food but rather ingest complex molecules like carbohydrates from the environment.
Phototrophs are a group of organisms unlike chemotrophs that depend on the source of light or sunlight for synthesizing its food or organic molecules.
Photoautotrophs are basically photosynthetic plants which are able to carry out photosynthesis ie the conversion of CO2 and H2O to give Glucose and Oxygen in the presence of sunlight.
Photohetrotrophs are a class of organisms that do not synthesize their own food but rely on other organisms or already made organic molecules.
For ectotherms, such as lizards, their body temperature and metabolic rate may change with the environmental temperature. What do researchers call the resting metabolic rate at a given temperature for an ectotherm?
Answer:
Standard metabolic rate
Explanation:
The resting metabolic rate at a given temperature for an ectotherm is called Standard metabolic rate. On the other hand, the resting metabolic rate at a given temperature for an endotherm is called Basal metabolic rate.
Standard metabolic rate is the minimal metabolic rate required to sustain an organism life at a stipulated temperature. In darkened environment when at rest and unstressed and at post-absorptive state(i.e not actively involved in food digestion), the Standard metabolic rate of an organism can be effectively measured.
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. The inheritance of Marfan syndrome is an example of ______. a) a recessive disorder b) pleiotropy c) codominance d) incomplete dominance
Answer:
pleiotropy
Explanation:
When a single gene influences more than one phenotype that is unrelated to each other then this phenomenon is termed as pleiotropy. The gene that causes pleiotropy is called a pleiotropic gene. In the given question, the disease that is Marfan syndrome is occurring due to the inheritance of a single allele that is defective. However, this single gene is affecting various phenotypes such as the length of the limbs, the cardiovascular system and the eyes and all these different characters affected are quite unrelated to each other.Therefore, it can be said that Marfan Syndrome is an example of a pleiotropic condition.When peas with red flowers are crossed with peas with white flowers and then the resulting plants are AGAIN crossed, what will be the ratio of pea plants with red flowers to plants with white flowers in this SECOND generation?
Answer:
Red flowers: white flowers 3:1
Explanation:
Gregor Mendel crossed an homozygous dominant pea plant that produced red flowers (RR) and a homozygous recessive pea plant that produces white flowers (rr). He got a F1 generation where all the offsprings were red-flowered heterozygous (Rr).
The hybrids in F1 generation were then self-crossed (see attached image). The phenotypic ratio was 3:1 i.e. 3 red-flowered pea plants to 1 white-flowered pea plants.
RR, Rr, Rr and rr
Some questions fall outside the realm of science; which of the following questions could not be answered using the scientific method?
a. What is the function of the appendix in human beings?
b. Why is it unethical to test newly developed drugs in animals?
c. Why do smokers develop lung cancer more frequently than nonsmokers?
d. Why is it so difficult to quit smoking?
Answer:
The correct answer is - option B.
Explanation:
Scientific method is the method that is based on sequenced scientific logic based steps to answer questions. Such questions are known as scientific questions that can be answered by the logic and not based on the believes or social norms.
The options provided with the questions are easily answer by the logic and scientific method by the knowledge except the option B that deal with ethical and unethical phenomena which is not depend on scientific knowledge.
Thus, the correct answer is option B.
The question that cannot be answered using the scientific method is 'Why is it unethical to test newly developed drugs in animals?' because it involves ethics, which cannot be scientifically tested.
Explanation:The question that could not be answered using the scientific method is 'Why is it unethical to test newly developed drugs in animals?' This is because ethics involve values and moral reasoning, which cannot be empirically tested or measured in the same way biological processes can be. Scientific methods rely on observation, measurement, and experimentation to test hypotheses about the natural world, and while they can help us understand the effects of drugs on biological systems, they cannot address moral and ethical questions such as the rights and welfare of animals.
To illustrate, questions that could be scientifically investigated include the function of the appendix in human beings and why smokers develop lung cancer more frequently than nonsmokers, as these can be explored via empirical evidence and experimental research. In contrast, why it is so difficult for some individuals to quit smoking could also have a biological basis, but it involves subjective experiences and psychological factors that are not solely within the realm of empirical science.
In tigers, a recessive allele causes an absence of fur pigmentation (a white tiger) and a cross-eyed condition.
Part A
If two phenotypically normal tigers that are heterozygous at this locus are mated, what percentage of their offspring will be cross-eyed? Express your answer using the percent symbol and no spaces (for example, 10%).
Part B What percentage of cross-eyed tigers will be white? Express your answer using the percent symbol and no spaces (for example, 10%).
Answer:
A) 25%
B) 100%
Explanation:
This involves a single gene. Let's assume the gene is Z. The dominant allele (Z) produces a tiger with normal phenotype i.e. presence of fur pigmentation and no cross eye while the recessive allele (z) produces a tiger with no fur pigmentation (white) and cross-eye.
According to the question, a heterozygous tiger will have normal phenotype because the dominant allele (Z) is masking the expression of the recessive pair (z). Hence, in a cross between Zz and Zz (two heterozygous tigers), four possible offsprings will be produced, in which three(3) will be phenotypically normal (Zz) and one(1) will be phenotypically recessive (zz) i.e. possess cross-eye and white furs. Hence, the percentage of cross-eyed (recessive) tiger offsprings will be 1/4 × 100 = 25%. (See attached image)
For question B; The recessive allele for the gene induces both lack of fur pigmentation and cross-eyed phenotypes I.e. The two recessive phenotypes are caused by the same recessive alleles on the same locus. This means that a tiger that is cross-eyed must also be white-furred or lack fur pigmentation. Hence, the percentage of having a cross-eyed tiger that is white is 100%.
When two heterozygous tigers are mated, 25% of the offspring will be cross-eyed, and 100% of cross-eyed tigers will be white.
Explanation:In tigers, let's assume white fur and cross-eyed condition are represented by the recessive allele 'a', and the normal pigment and eye condition are represented by the dominant allele 'A'. If two heterozygous tigers (Aa) are mated, the probability of having cross-eyed (recessive phenotype) offspring can be found by setting up a Punnett square.
The genotypes of the offspring would be as follows:
AA (normal)Aa (normal, but carrier)Aa (normal, but carrier)aa (cross-eyed and white)This means, 1 out of 4 or 25% of the offspring will be cross-eyed, which answers Part A.
For Part B, since all cross-eyed tigers must be homozygous recessive (aa), 100% of cross-eyed tigers will be white. Thus, all cross-eyed tigers will have white fur.
Please help!! Punnett squares
Answer:
The women would be heterozygous for the blood type B.
Explanation:
For the child to develop blood type A, the mother should be heterozygous for the blood type B.
B O
A AB AO
B BB BO
Hence, the results from this punnet square tell that the a mother heterozygous from blood type B when crossed with a father having blood type AB, will have the probability to produce 25% AB type, 25% AO type, 25% BB type and 25% B0 type offsprings. This type of punnet square will be blood testing punnet square.
During the _________ stage of birth (which is called the "descent and emergence of the baby" stage), the mother bears down hard to push the baby out of her body; this stage typically lasts 45-60 minutes.
Answer:
Second
Explanation:
Childbirth involves three stages:
The first stage starts with the onset of true labor and lasts until the cervix is completely dilated to 10 cm.
The second stage continues after the cervix is dilated to 10 cm until the delivery of your baby. This stage is called the "descent and emergence of the baby" stage. It involves the pushing by the mother and the delivery of your baby. Now that your cervix has fully dilated to 10 cm, this is the time for mother to help by pushing. This stage can last from 20 minutes to 2 hours.
The third stage involves the delivery of the placenta.
The stage of birth in question is the second stage of labor, also known as the pushing stage. It lasts for 45-60 minutes and involves the mother pushing the baby out of her body.
Explanation:The stage of birth described in the question is known as the second stage of labor. During this stage, also known as the pushing stage, the mother uses her abdominal muscles to bear down and push the baby out of her body. It typically lasts 45-60 minutes but can vary depending on the individual.
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Darwin studied actual birds on the galapagos islands instead of using a simulation. What do you call this simulation?
Answer:
Control
Explanation:
This is the observation designed to minimize the effect of variables other than the independent variable.
How many nerves and blood vessels are in a square inch of skin?
Answer:
20 feet blood vessels and 1000 nerve endings
Explanation:
The skin is the largest organ of the body and is composed of three layers that are epidermis, dermis and the subcutaneous layer. The outer layer is the epidermis consisting of cells that are tightly packed in around in 20 layers. The middle thick layer is the dermis that consist of glands, nerves, blood vessels, and hair follicles that provide skin its functions. The inner layer is the subcutaneous that is composed of connective tissue and fat.
The square inch of skin consist of 20 feet blood vessels, 1000 nerve endings, 650 sweat glands and 100 oil glands. The blood vessels supplies blood to the tissues and the nerve endings upon stimulation sends signals to the brain and generate response depending on the kind of stimulus like heat, pressure, pain, or temperature.
For 1981, 1987, and 1990, how does the frequency of left-mouthed breeding adults compare to the frequency of left-mouthed individuals in the entire population?
Answer:
The variation might occur in the population that leads to the evolution of the species. This variation may occur due to natural selection, mutation or recombination.
The variation might change the genotype and allelic frequency of the population and might also change the phenotype of the individual in the population. The breeding adults of the left mouthed in 1981, 1987 and 1990 shows variation and was equally opposite phenotype which is more common in the population.
If two chromosomes of a species are the same length and have similar centromere placements and yet are not homologous, what is different about them?
As per the two chromosomes of the spies that have the same length the genetic contents in the non-homologous chromosomes would be different.
What are the homologous chromosomes?The homologous chromosomes are those with the same lengths, share the same position of the centromere and have the same types and the location of the genes.
If 2 chromosomes of that species are of the same length and have a similar centromere placement and yet are not the same the genetic content would be different.
Find out more information about the chromosomes.
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Chromosomes that are similar in length and centromere placement but not homologous differ in their gene sequences. Homologous chromosomes have identical gene sequences, while non-homologous chromosomes don't.
Explanation:If two chromosomes of a species are the same length and have similar centromere placements and yet are not homologous, what differentiates them is their gene sequences or genetic contents.
Homologous chromosomes are not only identical in length and centromere placement but also have identical gene sequences at specific locations, or loci, which contain the genetic information to specify certain traits.
These chromosomes are derived from different parents and carry the same genes but may have different versions of these genes called alleles.
On the other hand, chromosomes that are similar in size and centromere placement but are not homologous will not carry the same genetic information.
For example, in humans, the X and Y chromosomes are a pair of sex chromosomes, but they are not homologous. They are similar length and have their centromeres placed similarly; however, their genetic contents significantly vary, except for a small region of homology that allows them pairing up during the formation of gametes.
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In order for an action potential to begin, the neuron must _____.
Answer:
Answer is depolarize.
Explanation:
Depolarization is one of the four stages of action potential. Other stages are hypopolarization, repolarization and hyperpolarization.
Action potential is known to occur when different ions are able to cross neuron membranes.
Depolarization occurs when the charge across a cell membrane is reversed.
It should be noted that, stimulation of other neurons or sensory receptors must have occurred before depolarization.
The nerve impulses in the nerve fibers of muscle are considered as one of the examples of action potential.
Consider the following astronomical statements. Classify each statement as either an observation, meaning something we have directly observed or measured, or an explanation, meaning something that we infer from observational or experimental evidence even though we cannot observe it directly.
[Observations]
- The Andromeda Galaxy is similar in structure to our own Milky Way
- All planets orbit the Sun in the same direction and nearly the same plane
- More distant galaxies are moving away from us faster than nearby galaxies
- Stars can shine brightly for billions of years
Answer:
[Observations]
- The Andromeda Galaxy is similar in structure to our own Milky Way
- All planets orbit the Sun in the same direction and nearly the same plane
- More distant galaxies are moving away from us faster than nearby galaxies
- Stars can shine brightly for billions of years
[Explanations]
- The universe is expanding because it began with a Big Bang
- The Andromeda and Milky Way galaxies formed in the same way
- The orderly orbits of planets arose from their formation in a rotating gas cloud
- Stars shine with energy generated by nuclear fusion in their cores
The Hershey and Chase experiments involved the preparation of two different types of radioactively labeled phage. Which of the following best explains why two preparations were required?
A. The bacteriophage used in the experiments was a T2 phage.
B. It was necessary that each of the two phage components, DNA and protein, be identifiable upon recovery at the end of the experiment.
C. Each scientist had his own method for labeling phage, so each conducted the same experiment using a different isotope.
D. Establishing the identity of the genetic material required observation of two phage generations.
Answer:
B. It was necessary that each of the two phage components, DNA and protein, be identifiable upon recovery at the end of the experiment.
Explanation:
Hershey and Martha Chase used radiolabeled the DNA of some of the bacteriophage cells with phosphorus (32P). They radiolabeled the sulfur (35S) of the coat protein in the second batch of the phage cells. They infected some of the bacterial cells with phage having radiolabeled DNA while the other E. coli cells were infected with the phage carrying radiolabeled coat protein. This allowed the clear identification of the radiolabelled molecule (DNA or protein) present in the host cell.
They observed that the E. coli cells infected with phage having radiolabeled DNA exhibited the radioactivity while the other batch of the host cell did not show it.
For a moment he had a fleeting picture of the strange glamour that had once invested the beaches. But the island was scorched up like dead wood – Simon was dead – and Jack had… The tears began to flow and sobs shook him.
Answer: died
Explanation: Simon was dead, and Jack had died. 'Was' is a past continuous tense word showing an action that had been performed moments, seconds, minutes or even years ago, and that action or event will continue to be in the past. 'Had' on the other hand is showing an event that just occured recently. Simon might have died 2 days ago and Jack's death might have come seconds ago.
A critical part of the plasma membrane is that it is selectivley permiable. This allows the plasma membrane to regulate transport across cellular boundaries:_______.
Answer:
Answer is true.
Explanation:
A cell membrane is considered as selectively permeable because it controls or regulates the type of molecules that can pass through it. Substances of small molecules are allowed by the cell membrane while substances with large molecules are not allowed to pass through. For example , amino acids and simple sugar can easily pass through the cell membrane while protein and starch can't pass through it.
The cell membrane is considered or described to be boundary or border between the interior part and exterior part of the cell.
Specialists who apply their knowledge of physiology, biomechanics, anatomy, and psychology in order to improve movements, working environments, and training programs in the workplace are called_________.A. ergonomists or human factors engineersB. work specialistsC. occupational therapistsD. occupational engineers
Answer:
Ergonomists or human factors engineers.
Explanation:
Egronomics may be defined as the scientific field that includes the interaction of the human psychology with the scientific theory and methods for the well being and overall development of humans.
Egronomists may be defined as the scientists that mainly studies the difefrent factors that affects the human psychology at the work place. The egronomists mainly work to design and evaluation of the different factors that makes the human compatible with their work place.
Thus, the answer is ergonomists.