What is a Barr body, and where is it found in a cell? b) Define the Lyon hypothesis.

Answer:

Metoclopramide is a drug widely used for its antiemetic effect (that is, used for the symptomatic treatment of nausea and vomiting). Its adverse reactions are varied, affecting even the central nervous system, causing extrapyramidal syndromes.

Explanation:

Due to the antidopaminergic action of metoclopramide. Signs and symptoms can range from spasms of the muscles of the face, neck or tongue, motor agitation and tremor, acatisia (feeling restless and in need of constant movement) and acute dystonic reactions. Extrapyramidal syndrome is transient and disappears after eliminating or decreasing the dose of metoclopramide.

Metoclopramide is a drug that can be administered intravenously. Its administration can be in bolus or by a continuous infusion. Is there any method of choice to prevent or reduce the occurrence of pyramidal syndromes?

A recent systematic review concluded that, compared with bolus administration, continuous intravenous infusion of metoclopramide reduced the occurrence of extrapyramidal side effects.

With this gesture we can perform quality care and try to avoid side effects to our patients.

Answer:

d. the 5' end

Explanation:

Capping is a co-transcriptional modification made to RNA in the nucleus after the first 25–30 nts are incorporated into the nascent transcript, which is synthetized in the 5' ---> 3' direction.

The cap consists of a methylated guanosine nucleotide added to the 5' end of the new mRNA transcript, and is important for several processes, which include:

Answer:

The correct option is: b. attenuated vaccine

Explanation:

FluMist is the trade name of the live attenuated influenza vaccine, manufactured by MedImmune. This vaccine is used for the prevention of influenza, also called flu.

It is an attenuated vaccine which is given in the form of nasal spray.

An attenuated vaccine alters the pathogen by reducing its virulence and makes it harmless.

Answer:

The correct answer is option D. True tissues.

Explanation:

The cell that made sponge does not form the tissue however sponge have cells that play important role and specific for specific function but does not have true tissues.

In other animal phyla cells form tissue or organ or organ systems and called as true tissues.

Thus, the correct answer is option D. True tissues.

It is mainly based on the true tissues.

Sponges are the multicelled organism of the phylum Porifera. The body of the sponges has various channels and pores, that allows water circulation.  

Sponges are multicellular organism that consists of pores and channels in their body for water circulation and lacks specific tissues. They have cells assigned with specific roles and functions but lack true tissues unlike animals of the other phyla.

The animals of the various phylum are classified based on the body cavity, tissues, symmetry,  fate of the blastopore.

Therefore, option d. is correct.

Learn more about sponges here:

https://brainly.com/question/9380649

Answer: Passive immunity

Explanation:

The strategy of vaccination was a type of passive immunity. Passive immunity can be introduced artificially when antibodies are given as a medication to the non immune individual.

This is done in case of vaccination, attenuated form of bacteria is injected or orally given to the individual to evoke immune response when the body is exposed to the same bacteria again.

The attenuated form of bacteria evoke the immune system to produce memory cells which will kill the bacteria when it is encountered for the second time.

Answer:

The process of ATP synthesis in both chloroplast and mitochondria is similar:  

1. Generation of electrochemical gradient across the membrane: The movement of electrons generates a difference in the concentration of protons across the membrane in both organelle. Due to this, an electrochemical gradient is established.

2. Movement of protons or hydrogen ions through ATP synthase: The generation of electrochemical gradient leads to the movement of options across the membrane through embedded ATP synthase enzyme.

Thus, ATP production in both the organelles is similar.

Answer: There are 4¹⁰⁰ possible strands, approximately 1.61x10⁶⁰

Explanation:

This is a combinatorics problem. Each nucleotide has the possibility of being one of the four common nucleotides, adenine (A), guanine (G), thymine (T) and cytosine (C).

If the strand would be 1 nucleotide long, the possibilities would be 4, one for each possible nucleotide. If the strand would be 2 nucleotides long, for each nucleotide on the first position there would be four possible nucleotides on the second position, giving 4x4=4²=16 possible strands.

For 3 nucleotides long you have 4 possible nucleotides for each of the 2-nucleotide-long strands, 4x4x4=4²=64 possible strands. Following that pattern, for a 100 nucleotide long DNA strand, there would be 4x4x...x4x4=4¹⁰⁰ possible strands.

Answer:

False.

Explanation:

Tolerance is when, after being exposed to a certain drug for a long period of time, the body can no longer respond to the same dose that used to trigger a biological response, so the dose has to be increased.

Answer:

a. DNA polymerase proofreading:   consequence of its absence is the DNA mutation

b.  Mismatch repair enzymes : consequence of its absence impedes homologous recombination resulting in the final mutation

c. Nucleotide excision repair enzymes : the absence of nucleotide cleavage repair enzymes would impede the functioning of damaged DNA repair mechanisms

Explanation:

a. DNA polymerases are the enzymes that form the DNA in cells. During DNA replication (copying), most DNA polymerases can "check their work" with each base they add. This process is called review. If the polymerase detects that you have added a wrong nucleotide (incorrectly paired), remove it and replace it immediately, before continuing with DNA synthesis

b. In homologous recombination, the information from the homologous chromosome that matches that of the damaged one (or from a sister chromatid if the DNA has been copied) is used to repair the fragmentation. In this process the two homologous chromosomes are approached and the undamaged region of the homologue or the chromatide is used as a template to replace the damaged region of the broken chromosome. Homologous recombination is "cleaner" than the union of non-homologous ends and does not usually cause 11 mutations

c. Excision repair: damage to one or a few DNA bases is usually fixed by removing (excising) and replacing the damaged region. In repair by base cleavage, only the damaged base is removed. In nucleotide excision repair, as in the mating repair we saw earlier, a nucleotide section is removed

The absence of DNA repair mechanisms such as DNA polymerase proofreading, mismatch repair enzymes, and nucleotide excision repair enzymes can lead to an elevated mutation rate, causing genomic instability and increasing the risk of cancer and genetic disorders.

Consequences of Missing DNA Repair Mechanisms

The integrity of DNA is safeguarded by various repair mechanisms. When these systems fail or are absent, the stability and function of an organism's genome are compromised. Here's what happens when certain DNA repair mechanisms are missing:

DNA polymerase proofreading: DNA polymerase adds nucleotides during DNA replication and conducts proofreading to ensure accuracy. If proofreading is compromised, incorrect bases may be incorporated, resulting in mutations which can lead to cancers or other genetic disorders.

Mismatch repair enzymes: These enzymes correct errors that escape proofreading during replication. Without mismatch repair, these errors become permanent, increasing mutation rates and contributing to diseases like cancer.

Nucleotide excision repair enzymes: These enzymes repair bulky lesions such as thymine dimers which are primarily caused by UV light. Absence of these enzymes may lead to a higher incidence of skin cancer due to the accumulation of these lesions.

In summary, the lack of these DNA repair mechanisms can result in increased mutation rates, leading to genomic instability, and may significantly raise the risk of cancer and other hereditary diseases.

Answer:

The correct answer is D.

Explanation:

Proto-oncogenes code for proteins that usually help to regulate cell growth and differentiation.

If they acquire a mutation, they become oncogenes and therefore can induce cancer.

Additionally, if they increase the amount of certain proteins concentration or acquire chromosomal translocations they can also become oncogenes.

Answer:

C Patterns

Explanation:

got 100 on quiz

The shell of the chambered nautilus the seeds in a sunflower and pineapples all exhibit a structure called the "Fibonacci spiral". This phenomenon represents the pattern phenomena by cross-cutting.

A series of numbers in which every number is the sum of the two its previous numbers Fibonacci spiral. It starts at  0 and 1, the sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, and goes on forever. Xn+2= Xn+1 + Xn is the mathematical equation that is used to describe or represent the  Fibonacci sequence.

Several people have claimed that there are many special properties of this numerical sequence. They say that it is “nature’s secret code” for the construction of perfect structures. Some examples given are the Great Pyramid at Giza and the iconic shape of the seashell that is used as the cover of most mathematical textbooks. But most of these assumptions are incorrect.

Therefore, this is a pattern phenomenon represented by cross-cutting.

Read more about the Fibonacci spiral, here

https://brainly.com/question/3141675

#SPJ2

Answer:

c. contributes in immunity

Explanation:

The mass of the lymphatic tissues that lack any capsule is known as lymphatic nodules. The lymphatic nodules are scattered in mucous membranes that line the various tracts.

The appendix has an aggregation of lymphatic nodules. The lymphatic nodules of the appendix contain immune cells to protect against diseases or infection. It prevents any possible entry of pathogen and subsequent infection through digestive system.

Answer:

False

Explanation:

Approximately 200 out of 200 million sperms ejaculated during intercourse reach the general vicinity of the egg.  They sperms must undergo capacitation during which dilute inhibitory factors fluids of the female reproductive tract weaken the membrane of the sperm head so that head of the sperm can be broken easily when it came in contact with the egg.

The first sperm to reach an egg isn’t the one to fertilize it because the egg is surrounded by a gelatinous membrane called the zona pellucida. Outside this layer, a layer of small granulosa cells also present.

Therefore, it requires numerous sperm to clear a path through these barriers before one of them can penetrate the egg and fertilize it.

Answer: True

Explanation:

The ear is a organ found in the body of mammals and other animals that helps in hearing.

The ear consists of outer part and inner part. The outer part of the ear converges the sound waves and the transfers to the ear canal.

The sound is then amplified inside the ear and we hear sound. There is a fluid which is found inside the inner ear contains a fluid that helps in balancing of the body.

Answer:

Yes they are polymers of monosaccharides.

Explanation:

Disaccharides are polymers of monosaccharides, which are simple sugar molecules such as glucose. Monosaccharides, monomers, are linked by glycosidic bonds to make disaccharides.

Example; the linkage of glucose and fructose to make sucrose.

Answer:

The exons may be defined as the coding region of the RNA that codes for the particular amino acid. The introns are the non coding region of RNA and must be removed in the final RNA product.

Exon shuffling result in the formation of new gene. The alteration of the exon and intron structure leads to the new gene function in evolution. The genes that are favored and conserved in the evolution perform new gene function. The genes that are selected against are deleted during the evolution.

The exon/intron structure in genes facilitates the evolution of new functions through exon shuffling, alternative splicing, and gene duplication, significantly contributing to genetic diversity and adaptability.

The exon/intron structure of genes is pivotal in the evolution of new gene functions. Introns, which are non-coding sequences, serve as a buffer against deleterious mutations, and through unequal recombination during meiosis, they can lead to gene duplication and exon shuffling. This occurrence can result in new proteins with additional structural domains and functions, contributing to genetic diversity and evolutionary progress.

Exon shuffling is a mechanism by which exons can be mixed and matched between genes, potentially creating proteins that carry out new functions. Additionally, introns and their associated sequences play a crucial role in alternative splicing, which allows for the production of multiple protein variants from a single gene, further increasing the potential for diversity and adaptability.

Gene duplication, which can occur due to non-homologous recombination facilitated by introns, allows one gene copy to accumulate mutations while the other maintains its original function. This duplicated gene can then evolve over time, adding to the pool of selectable DNA sequences and leading to an increase in species diversity and evolutionary innovation.

Answer:

Cellular membranes or plasma membranes has many functions. Some of these include regulation of cellular transport, and responding to cellular signals or hormones.

The plasma membrane is made up of the phospholipid bilayer with embedded transmembrane proteins. This makes the cell membrane semi-permeable. Movements of substances depend on the composition of the molecules e.g. glucose and amino acids, as needed by the pancreatic cells. These are larger and uncharged molecules and can't pass freely through the membrane so they utilize the transmembrane proteins via attaching to carrier proteins. This is called passive transport. On the other hand, in active transport, ATP is used to transfer molecules, like Hydrogen, from a low to high electrochemical gradient.

Other kinds of cellular transport are:

The cell membrane is able to signal other neighboring cells by utilizing complex proteins. These proteins may take form as receptors or markers.

They act as receivers of extracellular signals and spark intracellular processes. These receive signals from hormones, growth factors, etc.

These allow the cells to identify each other and respond if this cell is needs further development as in organ development, or a foreign body to the system.

Answer:

False.

Explanation:

Bacteria are the prokaryotic organism that lacks the well developed nucleus and the membrane bound cell organelle. The animal cells are the eukaryotic organisms.

Bacteria cells have cell walls that are made of the peptidoglycan layer. The cell wall of bacteria are important as it protect themselves from the extreme environment. The animal cells do not contain cell wall and they have plasma membrane only in their structure.

Thus, the correct answer is option (b).

Answer:

The correct answer is D) photolysis

Explanation:

Photolysis is a process in which light energy is used by photosystem II to split water which generates oxygen, H⁺ions end electrons. oxygen is released in the atmosphere and inhaled by animals and electrons are used to generate energy.

The electron released by the splitting of water is transferred to the first electron acceptor called pheophytin. This electron is passed through a series of complex and produce energy in the form of ATP and NADPH.

The process of photolysis does not occur in photosystem I because lysis of water takes place and electron is passed from photosystem II to photosystem I.

Photolysis is not directly associated with Photosystem I. Instead, it's a process that occurs in Photosystem II, where water molecules are broken down into oxygen, protons, and electrons.

The correct answer is D) photolysis. Photosystem I is a protein complex involved in the light-dependent reactions of photosynthesis. Its primary functions include harvesting light energy by chlorophyll (option A), receiving electrons from plastocyanin (option B), possessing a reaction center known as P700 (option C), and passing electrons to ferredoxin (option E).

In contrast, photolysis - the breaking down of molecules using light - is not directly associated with Photosystem I, but instead with Photosystem II, where water molecules are broken down into oxygen, protons, and electrons.

https://brainly.com/question/35138971

#SPJ3

Answer:

b. enzymes secreted in the pancreas

Explanation:

The pancreas is a gland which is situated in the abdomen. It functions as endocrine as well as an exocrine gland.

The endocrine part of the pancreas is the islets of Langerhans which secretes hormones insulin and glucagon directly into the bloodstream.

It releases pancreatic juice that contains digestive enzymes into the duodenum of the small intestine.

The final digestion of carbohydrates, protein and fats occur in the duodenum with the pancreatic enzymes.

The enzymes include:

The final enzymatic breakdown in the digestive processes of most proteins and carbohydrates are accomplished by: c. enzymes secreted in the brushborder.

An enzyme can be defined as a biological catalyst that typically speeds up (accelerates) the rate of a chemical reaction such as the break down of food by the digestive system, especially by lowering the activation energy of its chemical reactants.

Basically, the enzymes secreted in the brushborder are mainly responsible for the final enzymatic breakdown in the digestive processes of most proteins and carbohydrates.

Read more on enzyme here: https://brainly.com/question/18479863

In the cell cycle, G1 is the phase when the cell has the least amount of DNA. This DNA is duplicated during S phase, meaning the cell has twice as much DNA in the G2 phase. So, if Cell A has half as much DNA as cells B, C, and D, then Cell A is likely in the G1 phase.

In the cell cycle, the amount of DNA a cell has can help determine which phase it is in. The cell cycle consists of interphase (G1, S, and G2 phases), and the mitotic phase (including prophase, metaphase, anaphase, and telophase). During the G1 phase of the cell cycle, a cell has the least amount of DNA because it hasn't duplicated its DNA yet. DNA replication occurs during the S phase, so by the G2 phase, the cell has twice as much DNA as it did in G1. Thus, if Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue, Cell A is most likely in the G1 phase.

https://brainly.com/question/31898914

#SPJ6

Cell A is most likely in the G1 phase of the cell cycle, a stage prior to DNA synthesis, as it has half the amount of DNA than cells B, C, and D, which presumably already completed the S phase (DNA replication).

Cell A is most likely in the G1 phase of the cell cycle. The G1 phase is a period in the cell cycle during interphase, before DNA synthesis (S phase). In G1 phase, the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. At this stage, it has half as much DNA as it will have after it completes the S phase. Therefore, cells B, C, and D, each having twice as much DNA, are probably in the G2 phase, metaphase, or any phase after DNA replication (S phase) happened, during which the amount of DNA in the cell has already been doubled.

https://brainly.com/question/25282664

#SPJ11

Answer:

b. Because they have a low affinity for the H+

Explanation:

All electrons that enter the transport chain come from NADH and FADH2 molecules that are produced in earlier phases of cellular respiration: glycolysis, pyruvate oxidation and the citric acid cycle.

NADH is very good at donating electrons in redox reactions (that is, its electrons are at a high energy level), so you can transfer your electrons directly to complex I and transform it back into NAD +. The movement of electrons through complex I in a series of redox reactions releases energy, which the complex uses to pump protons from the matrix into the intermembrane space.

FADH2 is not as good for donating electrons as NADH (that is, its electrons are at a lower energy level), so it cannot transfer its electrons to complex I. Instead, it introduces electrons to the transport chain through complex II, which does not pump protons through the membrane.

The pattern of multiple codons encoding single amino acids could be an evolutionary protection mechanism against harmful mutations, providing a level of robustness and adaptability to organisms.

Most amino acids are indeed coded for by a set of similar codons. This redundancy in the genetic code, often referred to as degeneracy, can be explained from an evolutionary perspective. One possible explanation for this pattern could be that it provides a level of protection against harmful mutations. If a mutation occurs at the third position of a codon, it's often less likely to result in an amino acid change, which might provide an advantageous buffer against potentially harmful mutations. These synonymous mutations, or silent mutations, won't fundamentally change the resulting protein. Such a system would have been favored by natural selection, providing a level of robustness and adaptability to living organisms.

https://brainly.com/question/2276812

#SPJ3

Answer:

b. the rate at which the mRNA is degraded.

Explanation:

DNA is transcribed into mRNA which then joins ribosomes present in the cytoplasm to serve as a template for protein synthesis. Regulation of gene expression occurs at several levels.

One such regulatory mechanism is the stability of mRNA and the rate of its degradation which in turn affects the availability of template for the process of protein synthesis and thereby keeps a check on the total amount of protein being formed in a cell.

For example, a very short life span of bacterial mRNA (few minutes) allows them to regulate the pattern of protein synthesis quickly in response to the changes in surroundings.

The amount of protein synthesized from an mRNA molecule is influenced by the rate of mRNA degradation, which affects its stability and the duration of its presence in the cytoplasm for translation.

b is correct

The amount of protein made using a given mRNA molecule within a cell depends on several factors, one of which is the rate at which the mRNA is degraded. mRNA carries the genetic message from the DNA during the process known as transcription, and it dictates the synthesis of proteins through translation in conjunction with ribosomes and other cellular machinery.

The mRNA is short-lived, and its stability in the cytoplasm is crucial as it influences the amount of time available for translation. A longer mRNA lifespan allows for more protein production. Thus, the correct answer to the student's question is option b. the rate at which the mRNA is degraded.

https://brainly.com/question/29099024

#SPJ3

Answer:

The correct answer is option A. storage of bile.

Explanation:

The liver is the organ that is present on the right side of the abdomen and is almost the size of a football. Liver provides a different role in the body but major function of the liver is to detoxification of blood coming from the digestive tract. It produces different proteins and helpful in metabolizing all three major macromolecules that are protein, carbohydrate, and fat. The liver also produces the bile that is helpful in digestion.

Bile that produces and moves from the liver through bile ducts and stored in the gall bladder concentrated and secreted during or after food intake to assist the digestion process.

Thus, the correct answer is option A. storage of bile.

The liver does not store bile; instead, bile is stored in the gallbladder. The liver's functions include carbohydrate metabolism, detoxification of the blood, protein and lipid metabolism, and production of bile. Hence the correct answer is option A- Storage of bile.

The liver has a wide array of functions, but storage of bile is not one of them. Instead, the liver's roles include carbohydrate metabolism, detoxification of the blood, protein and lipid metabolism, and the production of bile which is involved in the emulsification and digestion of fats. The bile produced by the liver is stored in the gallbladder, not the liver itself. Therefore, the correct answer to the question 'ALL of the following are functions of the liver, EXCEPT:' is option a. Storage of bile.

https://brainly.com/question/29202439

#SPJ2

Answer:

It is fascinating to observe two distinct characters presented by the same plant. The inheritance of this plant can be determined easily by crossing the pure violets exhibiting yellow petals with dark brown marking and erect stems with violets exhibiting no markings, white petals, and prostate stems.  

The F1 progeny will originate as a hybrid of the two characters. These F1 plants will then be crossed between themselves and the F2 progeny would be clearly evaluated. If the F2 plants come in the phenotypic ratio of 3: 1, then it would indicate the pleiotropic effect of the alleles found in a single locus. If any other combinations arise post crossing, it would indicate that the non-wild type phenotype is because of many distinct mutant genes.  

Answer:

Three dangerous recreational drugs: crack cocaine, heroin, methamphetamines

Explanation:

Recreational drugs are the psychotropic drugs that induce an intoxicating effect. The three types of recreational drugs are depressants, stimulants, and hallucinogens.

The drugs affect the nervous system and induce hallucinations, euphoria, enhanced alertness and locomotion, low blood pressure, anesthesia, analgesia and memory impairment.

Some of the dangerous recreational drugs are crack cocaine, heroin, methamphetamines and alcohol.

Answer:

Spores are made by the millions, so some of them are likely to land in a good place to grow. Spores are lightweight and can drift around on the slightest air currents, so spores are spread far and wide. Spores have hard outer coverings to protect them until they begin to grow.

Explanation:

Answer:

The oxygen dissociation curve for hemoglobin is sigmoidal where as for myoglobin it is hyperbolic.

Explanation:

Oxygen dissociation curve: A graphical representation of relationship between partial pressure of O2 and percentage saturation of hemoglobin with oxygen is known as O2-dissociation curve. It is sigmoidal or S- shaped curve. The amount of O2 that can bind with Hb is determined by partial pressure of oxygen. The percentage of Hb that is bound with O2 is called percentage saturation of Hb.

In human adults, at pO2 of 25 mm of Hg the hemoglobin is 50% saturated with oxygen. This partial pressure is called P-50.

Hemoglobin shows S shaped curve due to cooperative binding of oxygen that is binding of first oxygen increases the ability of second oxygen binding and so on. One Hb can carry 4 oxygen molecules.

In case of myglobin, it has more affinity for oxygen but it has only one Fe+2 group, there is no cooperative binding. The curve obtained will be hyperbolic than being sigmoid.

Please find the attached image which shows both the curves. (Image reference: Evolution of Myoglobin and Hemoglobin ; Author and Curator: Larry H. Bernstein, MD, FCAP )

Since myoglobin has more affinity for oxygen its P-50 value is less, that is at low partial pressure of oxygen myoglobin gets 50% saturated. But the P-50 value for hemoglobin is high which means comparatively more partial pressure of O2 is needed for hemoglobin to be 50% saturated.

Answer:

No, there's no reason at all. mitosis can occur in any type of cell. The fundamental purpose of mitosis is to create identical cells. So, depending on the organism like plants or protist mitosis could even be involved in the production of gametes. In animals mitosis is a cell division that is mostly used for growth or tissue repair.