Answer:
Cancerous tissue has high mitotic index.
Explanation:
Mitotic index may be defined as the number of dividing cells divided by the total number of cells. Cell proliferation can be measured by mitotic index.
Cancerous cells are highly dividing cells and are less differentiated than normal cells. Cancer cells have higher mitotic index because the number of dividing cell is more in cancerous cell than the normal cells.
Answer:
Cancerous tissue has high mitotic index.
Explanation:
5. Discuss about the narrow sense conception of cytoskeleton and the classification and function of each components
Answer:
The narrow sense conception of cytoskeleton is introduced to protein fibres. These fibres are present inside the eukaryotic cells. This concept refers to the study of cytoskeleton. Cytoskeleton maintains the cell shape. Cytoskeleton have two components. These are nuclear skeleton and cytoplasmic skeleton.
Nuclear skeleton consist of core layer, nuclear matrix and chromosomal skeleton. Cytoplasmic skeleton comprises of microtubules, microfilaments and intermediate filaments.
Explanation:
The narrow sense conception of cytoskeleton is related to protein fibre structure in eukaryotic cells. The cytoskeleton system comprises of nucleus skeleton and cytoplasmic skeleton.
The nucleus skeleton consist of chromosomal skeleton, nuclear matrix and core layer.
Nuclear Matrix: It organize DNA into the cell with the help of nuclear lamina.
Core layer: It is the inner layer which connects nuclear matrix and outside fibres. It forms a grid structure between nucleus and cytoplasm.
Chromosome Skeleton: It is involved in packaging of chromosomes.
The cytoplasmic filaments consist of intermediate filament, microtubules and microfilaments.
Intermediate Filaments: It provides mechanical support to plasma membrane.
Microtubules: It maintains shape of the cell. It is involved cell wall formation.
Microfilaments: It is involved in myofibrils formation, acrosomal reaction and cytoplamic splitting like processes.
Acid chyme produced by the stomach is neutralized in the intestine by what?
Answer: Sodium bicarbonate produced by the Pancreas.
Explanation:
The mixture of partially digested food and gastric juice is called chyme. Chyme leaves the stomach through the pyloric sphincter to enter the small intestine. This is where all terminal digestion of carbohydrates, lipids, and proteins occurs, and where the products of digestions—amino acids, glucose, and so on—are absorbed into the blood. The first 25 centimeters is the duodenum; the remainder of the small intestine is divided into the jejunum and the ileum. The duodenum receives acidic chyme from the stomach, digestive enzymes, and bicarbonate from the pancreas, and bile from the liver and gallbladder. The pancreatic juice enzymes digest larger food molecules into smaller fragments.
Acid chyme from the stomach is neutralized in the intestine by bicarbonate, which is released by the pancreas. This happens in the duodenum, the first part of the small intestine.
Explanation:The acid chyme produced by the stomach is neutralized in the intestine by a substance called bicarbonate. Bicarbonate is released by the pancreas and works to neutralize the acidity of the chyme which is essential for the enzymes in the intestine to function properly. This process takes place in the duodenum, the first section of the small intestine, right after the stomach.
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Explain why there would be more errors in dna replication if thymine was sometimes able to form bonds with cytosine. PLEASE HELP
Answer:
DNA contains four base pairs: adenine, thymine, cytosine and guanine. Adenine forms bond with thymine, its a double bond, and cytosine forms triple bond with guanine.
Cytosine in natural process does not forms bond with thymine, but if it happen then many errors could occur in replication. As DNA is the basic material of cell and all genetic information lies in it, a single mutation can lead to fatal disorders, and when cytosine forms bond with thymine instead of guanine then the backbone of DNA would be distorted, RNA being formed from this DNA would also be have errors that would result in mutated proteins that can cause serious illness and destroy many natural processes.
Which of the following processes would manufacture glucose and other sugars from non-carbohydrate sources?
(a) Glycogenolysis
(b) Glycogenesis
(c) Gluconeogenesis
(d) Beta oxidation
Answer: (c) Gluconeogenesis
Explanation:
Gluconeogenesis (“new formation of glucose”) uses amino acids and lactic acid obtained from muscle proteins to convert into glucose. The glucocorticoids stimulate the liver to produce the enzymes needed for gluconeogenesis, the conversion of amino acids into glucose. This creation of glucose from protein is particularly important during very long periods of fasting or exercise when blood glucose levels might otherwise become dangerously low.
Junction between a motor neuron and a skeletal muscle fiber 1) sarcoplasmic reticulum 2) junction 3) motor end plate 4) axon terminal
Answer:
Junction.
Explanation:
Junction or neuromuscular junction may be defined as a type of chemical synapse and the site where motor neuron transmit information to the muscle fibers and causes the muscle contraction.
The junction is formed by the contact between the skeletal muscle fibre and motor neuron. The mutation in neuromuscular junction may cause autosomal disorders in an individual.
Hence, the correct answer is option (2).
Briefly differentiate "White Matter" & "Grey Matter".
Answer:
The CNS, or central nervous system is comprised of neurons, the cell units that form it. These cells, in turn, are formed by their cell bodies, the dendrites on them and the terminal ends of the axons, which are like the connectors, or roadways, for neurons. When viewed on a microscope, brain tissue, particularly, looks stained with two different colors: grey, or pinkisk, for the grey matter, and whiter for the white matter, which are the axons. This is basically why the two are called grey matter and white matter of the CNS.
So one difference between these two matters is the color they display when viewed. The second is the parts of the neuron that form the two; while the white matter is formed from the neuronal axons, the grey matter is formed by the dendrites, cell bodies and axonal terminals. A third differentiation is that most synaptic activity takes place in the grey matter, while most conduction of information from the cell bodies is performed by the axons.
White matter, consisting of myelinated axons, contributes to the CNS's communication network, while gray matter contains neuronal cell bodies and is involved in processing. Their composition difference, particularly the presence of fatty myelin in white matter, makes them distinguishable on MRI images. Brain development continues through adolescence, affecting the gray to white matter ratio.
Explanation:White matter and gray matter are two distinct types of nervous tissue found in the central nervous system (CNS). Gray matter consists primarily of neuronal cell bodies, dendrites, and non-myelinated axons, which give it a grayish appearance and is primarily involved in processing and cognition. It makes up the outer cortex of the brain. White matter, on the other hand, is made up of myelinated axons that form tracts and facilitate rapid communication between different gray matter areas.
The fatty myelin sheath around the axons gives white matter its characteristic lighter color. This difference can be easily identified in MRI images due to the contrast provided by the fatty tissue and water content. While gray matter is associated with the cortex and processing centers, white matter acts as a network of conduits providing connectivity and communication across different brain regions.
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What is a ductless gland?
Which of the following scenarios is most likely to occur if the climate continues on its current trajectory? a. Continental glaciers will form and expand outward from Canada and Norway. b. Cities like New York, New Orleans, and Miami will be flooded by ocean water. c. Large expanses of continental shelf will be exposed above sea level. d. Glaciers will grow larger, carve more U-shaped valleys, and deposit moraines.
Answer:
b. Cities like New York, New Orleans, and Miami will be flooded by ocean water.
Explanation:
The theory says global warming will cause the temperature of the planetary atmosphere to rise. The hotter environment will make ice masses of Greenland, and the poles to melt completely and make coastal cities like New York, New Orleans, and Miami flooded by the ocean.
Where is the pyramidal decussation?
Answer:
Pyramidal decussation is at the junction of medulla and spinal cord.
Explanation:
Pyramidal decussation may be defined as the the fibers that cross the corticospinal tract from one side to the junction and the other side to the central nervous system.
Pyramidal decussation is the point at the junction between spinal cord and medulla. The motor fibers crosses the midline from the medullary pyramids.
1. In the carbon cycle, the role of plants is to
Answer:
Release Oxygen and absorb Carbos dioxide from the air
Imagine a population that has 180 A1A1 individuals, 144 A1A2 individuals, and 175 A2A2 individuals. Male A1A1 is the preferred mate of females and gets all the matings. What would the genotype frequencies be for the A1A2 offspring of this population? Answer to 2 decimal places.
Answer:
[tex]0.288[/tex]
Explanation:
Given
Individuals in a population having genotype A1A1 [tex]= 180[/tex]
Individuals in a population having genotype A1A2 [tex]= 144[/tex]
Individuals in a population having genotype A2A2 [tex]= 175[/tex]
Hence, the total number of individuals in a population [tex]= 180 + 144+ 175\\= 499\\[/tex]
Thus, frequency of Individuals in a population having genotype A1A2 [tex]= \frac{X}{Y}[/tex]
Where X [tex]=[/tex] Individuals in a population having genotype A1A2
Y [tex]=[/tex] total population
Substituting the given values in above equation, we get -
[tex]\frac{144}{499} \\0.288\\[/tex]
The muscle that serves as the prime mover during a movement is called the
Answer:
Agonist
Explanation:
The muscle that serves as a prime mover during a movement is called "agonist". Agonist refer to the leader muscles that contract and cause the movement.
For example, the deltoid muscle is the prime mover or agonist. Contraction of deltoid muscle causes abduction of the arm. An agonist for one type of movement may serve as antagonist or fixator for some other movement.
Which condition involves an uninjured body part experiencing pain as the result of injury to another part of the body?
Select one:
a. sensory adaptation
b. referred pain
c. receptor potential
d. interceptors
Answer:
Referred pain
Explanation:
Referred pain may be defined as the pain perceived at differnet location of body other than the individual pain location.
Referred pain depends upon the intensity and duration of the pain. Refereed pain is generally generated by the potent mechanism of temporal summation. Referred pain is the condition of the body in which the uninjured body part experiences pain due to the injury of another body part.
Thus, the correct answer is option (b).
True or False: Smooth muscle is under control of the autonomic nervous system.
Answer:
True.
Explanation:
Autonomic nervous system is the division of peripheral nervous system. Autonomic nervous system control the involuntary actions of body like digestion, respiration, urination and heart rate.
Autonomic nervous system supplies the glands and smooth muscle and regulates the function of the internal organs. Hence, the smooth muscle is controlled by autonomic nervous system.
Thus, the given statement is true.
explain the roles of acetylcholine and GRP in gastrin secretion?
Answer:
Acetylcholine and GRP stimulates and increase the gastrin secretion in the stomach.
Explanation:
Acetylcholine can acts as a neurotransmitter as well as hormone. The parasymapthetic nerves release acetylcholine that stimulates the release of gastrin secretion in the stomach and helps in the process of digestion.
Gastrin releasing peptide (GRP) acts as a regulatory molecule of the gastrin. GRP is a neuropeptide hormones that helps in the secretion of gastrin by stimulating the G cells of the stomach.
Thus, both GRP and acetylcholine stimulates the gastrin secretion.
Acetylcholine and GRP play crucial roles in the secretion of gastrin, which is essential for the production of hydrochloric acid (HCl) in the stomach, facilitating protein digestion and smooth muscle contractions, while also featuring mechanisms to prevent excessive acid secretion.
Explanation:The roles of acetylcholine and GRP (gastrin-releasing peptide) in gastrin secretion are central to the process of gastric acid production, which is crucial for protein digestion in the stomach. When food enters the stomach, it causes distention that activates stretch receptors. This, in turn, stimulates parasympathetic neurons to release acetylcholine, which increases the secretion of gastric juice. Additionally, partially digested proteins, caffeine, and a rising pH level in the stomach stimulate the release of gastrin from enteroendocrine G cells.
Gastrin then prompts parietal cells to increase their production of hydrochloric acid (HCl), essential for converting pepsinogen to pepsin, and for further protein digestion. This hormone not only stimulates acid and enzyme production but also triggers vigorous smooth muscle contractions. However, the stomach has built-in safeguards to prevent excessive acid secretion and potential heartburn, such as suspending HCl secretion and increasing mucous production when pH levels drop too low, exhibiting a natural mechanism for maintaining homeostasis.
1. Which of the following gene is responsible for an amino acid synthesis in YAC vector?
CEN
URA3
ARS
TRP1
Answer:
option a
Explanation:
cen
Chymotrypsin
a. is secreted by the pancreatic acinar cells
b. digests proteins into peptides
c. works in the small intestine
d. all of the above
Answer: d. all of the above
Explanation:
Chymotrypsin is produced by the Pancreas and has the function of digesting proteins.It consists of three polypeptide chains connected by two inter-chain disulfide bridges. Chymotrypsin exerts an important biological function which is the hydrolysis of proteins in the small intestine. The cleavage of peptide bonds is selective, occurring only on the carboxyl side of aromatic side chains of tyrosine, tryptophan and phenylalanine, and large hydrophobic radicals such as methionine. Chymotrypsin also hydrolyzes ester
In fermentation the molecules of NADH are________while the organic molecules are _________.
A- oxidize, oxidize
B- reduce, reduce
C- oxidize, reduce
D-reduce, oxidize
Answer:
The correct answer is option C- "oxidize, reduce".
Explanation:
Fermentation is a process analogous to cellular respiration and, just like the latter, it involves oxidization and reduction of molecules with the final purpose of producing energy. During the process of fermentation nicotinamide adenine dinucleotide + hydrogen (NADH) is oxidized to its original form of NAD with a plus charge; while other organic molecules such as piruvate are reduced.
In fermentation, NADH molecules are oxidized, and organic molecules are reduced. This reaction allows NAD+ to be regenerated from NADH enabling glycolysis to continue anaerobically.
Explanation:In fermentation, the molecules of NADH are oxidized while the organic molecules are reduced. This process involves glycolysis where glucose is broken down, and during the latter stages, NADH donates electrons to an organic molecule, converting it to a more reduced form such as ethanol in alcoholic fermentation. At the same time, NADH is oxidized back to NAD+, which allows glycolysis to continue in the absence of oxygen.
Specifically, during alcoholic fermentation, acetaldehyde is reduced to ethanol using the electrons from NADH, simultaneously oxidizing NADH back to NAD+. This recycling of NAD+ is crucial for glycolysis to proceed in anaerobic conditions, providing cells with ATP. Unlike processes requiring oxygen, fermentation does not utilize the TCA cycle or the electron transport chain and relies on organic molecules to accept the electrons that were carried by NADH.
Red–green color blindness is an X-linked recessive trait in humans. Polydactyly (extra fingers and toes) is an autosomal dominant trait. Martha has normal fingers and toes and normal color vision. Her mother is normal in all respects, but her father is color blind and polydactylous. Bill is color blind and polydactylous. His mother has normal color vision and normal fingers and toes. If Bill and Martha marry, what proportions of children with specific phenotypes would they be expected to produce? The answers only include the proportions of some of the possible phenotypes; other phenotypes are also expected to occur but are not included.
Answer:
The girls with polydactyly color-blind and is 1/8, the boys with normal fingers and color vision is 1/8.
Explanation:
X - linked recessive trait may be defined as the trait that are normally passes down from mother to son. Males have high chances since they have only one X chromosme. The female should have both X chromosome affected to express the trait. Autosomal dominant trait express the trait in both the homozygous dominant and heterozygous condition.
The red - green color blinded male with polydactylous is married with female that have normal color vision and normal toes and finger. With the help of pedigree chart and probability,the outcome of their children with specific phenotype can be calculated.
Martha is normal for poldactyly and contains recessive trait for polydactyly. She is a carrier for the color blindness as his father is affected by the disease. Bill is affected by the color blindness and heterozygous for the polydactyly trait. The marriage between marry and bill have the children with 1/8 proportion of the girls can be color bind and shows polydactyly {1/4 ( girls with color blindness) × 1/2 ( the probability of polydactyly}. 1/8 proportion of the boys with normal vision and normal toes and finger {1/4 (boys are normal) × 1/2 ( the probability of normal toes and finger}.
If Bill and Martha marry, their children would be expected to have a 50% chance of being color blind and polydactylous, 25% chance of having normal color vision and normal fingers and toes, and a 25% chance of having normal color vision and polydactylous fingers and toes.
Explanation:If Bill and Martha marry, the proportions of children with specific phenotypes that they would be expected to produce can be determined by considering the inheritance patterns of red-green color blindness and polydactyly.
Red-Green Color Blindness:Since Martha's father is color blind, Martha is a carrier of the red-green color blindness gene on one of her X chromosomes. Bill, being color blind himself, has the red-green color blindness gene on both of his X chromosomes.
If Martha and Bill have children, the possible phenotypes are:
50% of sons: Color blind and polydactylous25% of daughters: Normal color vision and normal fingers and toes25% of sons: Normal color vision and polydactylousPolydactyly:Since Martha has normal fingers and toes and her mother also has normal fingers and toes, Martha does not carry the polydactyly gene. However, Bill is polydactylous, so he carries the polydactyly gene.
If Martha and Bill have children, the possible phenotypes are:
50% of sons: Color blind and polydactylous25% of daughters: Normal color vision and normal fingers and toes25% of sons: Normal color vision and polydactylousLearn more about Inheritance patterns here:https://brainly.com/question/780871
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What is the perimesencephalic subarachnoid hemorrhage?
Answer: Perimesencephalic haemorrhage (PSH) is defined as confined bleeding in the cisterns around the mesencephalon, called: the cerebral aqueduct, tegmentum, the tectum, and the cerebral peduncles.
Explanation:
PSH has a probable incidence in patients with negative angiographies of around 50% to 75%. It is a pathology with no predominant age range, reported in all ages in the literature, including childhood. By definition, the condition corresponds to a tomographic finding of blood in the interpeduncular cistern that may extend to the other portions of the mesencephalon. This pathogenesis has not yet been completely clarified, but it is believed to come from a nonarterial source, assuming venous or capillary origin.
Bacteria are grown in 15N (heavy) medium and then transferred to 14N (light) medium and are allowed to replicate for 1 generation. The DNA is subsequently isolated and centrifuged in a CsCl2 gradient to yield what type of gradient band(s)?
Answer:
The intermediate density band is observed.
Explanation:
Messelson and Sthal's explained the model of semi conservative nature of DNA replication. According to this model, the newly synthesized DNA molecule contains one newly synthesized strand and one parental strand.
Firstly, bacteria grown in 15N media is transferred to 14N media. The isolated DNA is centrifuged and intermediate density DNA band is observed that contains one strand of 15N (parental strand) and one strand of 14N (newly synthesized strand).
Bacteria grown in a 15N medium and then transferred to a 14N medium for one generation produce DNA that, when centrifuged in a CsCl2 gradient, forms a band at an intermediate position between DNA formed in 15N and 14N. This supports the semi-conservative replication model of DNA.
Explanation:The experiment you're referring to was conducted by Matthew Meselson and Franklin Stahl. They used E. coli and grew it initially in a heavy nitrogen medium (15N). Afterward, these bacteria were transferred into a 14N (lighter nitrogen) medium where they were grown for one generation.
During the replication in the 14N medium, DNA from the bacteria was isolated and centrifuged in a cesium chloride (CsCl2) gradient. The result was, that a single band was observed which settled at an intermediate position between DNA formed in 15N and 14N. This finding supports a semi-conservative replication model where each new DNA molecule consists of one old and one new strand.
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Which of the following vitamins is used to construct the coenzymes NADH and NADPH?
a. Riboflavin
b. Panthothenic acid
c. Vitamin B12
d. Niacin
Answer: d. Niacin
Explanation:
Many vitamins are parts of coenzymes. In numerous oxidation-reduction reactions that are catalyzed by enzymes, the electrons pass in pairs from the active site of the enzyme to a coenzyme that serves as the electron acceptor. Vitamin B3 or Niacin is used to construct the coenzymes NADH and NADPH, their sources for human ingestion are liver, lean meats, and grains. Its deficiency in consumption leads to Pellagra, inflammation of nerves and mental disorders.
Final answer:
D) Niacin (Vitamin B3) is the vitamin used to construct the coenzymes NADH and NADPH, which are essential for metabolic processes such as energy production.
Explanation:
The vitamin that is used to construct the coenzymes NADH and NADPH is niacin (B3). These coenzymes play a crucial role in various metabolic processes, including energy production and synthesis of fatty acids and steroids. Niacin is therefore essential for the conversion of food into energy and for maintaining healthy cells.
It's important to note that riboflavin (B2) is involved in the formation of another coenzyme, flavin adenine dinucleotide (FAD), which is also used in cellular respiration but is different from NADH and NADPH.
4)
The forelimbs of manatees, penguins, seals, and sea turtles are all flipper-shaped. This is an example of
convergent evolution to a structure permitting movement in water.
natural selection to a structure permitting movement in water.
adaptations to eating fish.
inheriting a common trait from a recent common ancestor.
selective breeding for the flipperlike forelimbs by humans.
Answer:
Option (A)
Explanation:
Convergent evolution may be defined as the independent evolution of similar features in different species. This evolution shows analogous structure that perform similar function but do not have a common ancestor.
Penguins, sea turtles and manatees forelimb is an example of convergent evolution because similar forelimb structure evolution has occurred in different species lineage. The convergent evolution of forelimb structure in these species permit movement in water.
Thus, the correct answer is option (A).
Which of the following is an effect of opsonization?A) increased adherence of phagocytes to microorganismsB) increased margination of phagocytesC) increased diapedesis of phagocytesD) inflammationE) cytolysis
Answer: A) increased adherence of phagocytes to microorganisms
Explanation:
The phenomenon of phagocytosis can be facilitated by certain substances called opsonins. Particles coated by antibodies or by certain products of the activation complement system adhere to the phagocyte membrane and are internalized more rapidly and intensely than those that are not opsonized. In the macrophage membrane, there are surface molecules, known as receptors, that have an affinity for these opsonins.
Opsonization increases the adherence of phagocytes to microorganisms, allowing for easier recognition, engulfment, and destruction of the pathogen by the immune system.
Explanation:The effect of opsonization is increased adherence of phagocytes to microorganisms. Opsonization is a process where pathogens are coated with a chemical substance, known as opsonin, which makes them more recognizable for phagocytic cells (like macrophages or neutrophils). This coating aids in the recognition, engulfment, and destruction of the pathogen by these cells. For instance, antibodies complexed with macromolecules, such as IgM and IgG in serum that bind to antigens, increase the attraction of phagocytic cells, mark these pathogens for destruction, and so enhance opsonization, leading to rapid clearing of pathogens.
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The second messenger in the following G-protein-linked-receptor pathway is signal moleculeG protein linked receptor activated G protein adenylate cyclase -> CAMP Select one: a. signal molecule b. activated G protein c. adenylate cyclase d. CAMP
Answer:
Answer is D - cAMP.
Explanation:
cAMP is a small molecule that functions as an intracellular signaling molecule - a second messenger. The first messenger would be the thing that activated the GPCR (e.g. a hormone). The GPCR is a signal transducer (converts extracellular signal to intracellular signal). Once activated, the GPCR activates adenylate cyclase which can be called a signal effector - it is an enzyme that produces cAMP.
What are the four types of tissues?
The term ''tissue'' refers to a group of similar cells. Being a combination of equal cells, a tissue has the same function in any part of the body.
The four types of tissues are:
. The epithelial tissue
. The connective tissue
. Muscle tissue
. The nervous tissue
. The epithelial tissue serves as a cover, among these are the skin and the lining of several ducts inside the body. It is divided into two general classifications: Simple Epithelium and Stratified Epithelium.
. The connective tissue supports and joins other tissues such as bone, blood and lymphatic as well as adipose tissue and reticular tissue.
. Muscle tissue consists of striated or voluntary muscles that move the skeleton and smooth muscle, such as the one that surrounds the stomach. It is divided into three types: Skeletal Muscle Tissue, Cardiac Muscle Tissue and Smooth Muscle Tissue.
. Nervous tissue is formed by nerve cells or neurons and serves to carry messages to and from various parts of the body. This tissue is present mostly in the brains and spinal cord. It has two types of tissue: The Nerve Cell and the Neuroglia.
Which of the following fat-soluble vitamins is an antioxidant necessary for synthesizing visual pigments, can be found in butter and leafy green vegetables, and can lead to blindness when a person's diet is deficient in it?
a. Vitamin D
b. Vitamin A
c. Vitamin K
d. Vitamin E
The correct answer is B. Vitamin A.
Vitamin A (retinol, retinoic acid) is a fat-soluble vitamin important for vision, growth, cell division, reproduction and immunity. It also has antioxidant properties.
Vitamin A is present in many foods, such as spinach, dairy products and liver. Other sources are foods rich in beta-carotene, such as leafy vegetables, carrots and cantaloupe. Your body transforms beta-carotene into vitamin A.
There are two dofferent types of vitamin A. The first type, preformed vitamin A, it is found in beef, poultry, fish and dairy products. The second type, provitamin A, is found in fruits,vegetables and other products of vegetable origin. The most common type of provitamin A present in foods and dietary supplements is beta-carotene.
Not consuming enough vitamin A, can cause diseases (which can be avioded with a good diet). Vitamin A plays a very important role in vision. On the one hand, it is essential for the production of the pigment consumed by photoreceptors responsible for vision in darkness. Therefore, low levels of vitamin A lead to night blindness.
Answer:
Vitamin A
Explanation:
Because thats the answer
Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because A) oligodendrocytes form a continuous myelin sheath around the axons. B) the endothelium of CNS capillaries forms a blood-brain barrier. C) the neurolemma is impermeable to most molecules. D) ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons. E) astrocytes form a capsule around neurons. B Extensive damage to oligodendrocytes in the CNS could result in
Answer:
B. the endothelium of CNS capillaries forms a blood-brain barrier
Explanation:
Commonly known as the blood-brain barrier or BBB is formed by the action of endothelial cells of brain which line the cerebral microvasculature. The BBB is a vital mechanism that protects the brain from the action of many circulating agents which are present in different medications like xenobiotics or other neurotransmitters which can disrupt the neural functions or harm them. The BBB also functions to protect the brain from the fluctuations in plasma composition of brain cells.
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You are studying a protein called myprotein in the cytosol. You want to see if another protein called, otherprotein, is required for folding. You isolate the cytosolic fraction using salt precipitation. You want to perform an experiment to find if otherprotein binds and interacts with mylittleprotein. Which assay would be best to perform first?
a. SDS PAGE to see the banding pattern showing all the proteins that interact
b. Immunopreciptation, because this will allow us to pull down proteins that interact
c. Size chromatography, because chances are the proteins that interact are the same size
d. Affinity Chromatography, because we know that it binds other proteins
Answer:
size chromatography, because chance are the protein that interact are the same size
36. In the Calvin cycle, where plants use the energy from photosynthesis to synthesize glucose, what enzyme is need for carbon fixation?
a. Rubisco
b. Crisco
c. Formaldehyde
d. Lactase
Answer: a. Rubisco
Explanation:
Photosynthesis is a way of making organic molecules from carbon dioxide (CO2). To build organic molecules, cells use raw materials provided by the light reactions. 1,5-bisphosphate carboxylase, also known as Rubisco, is the enzyme needed for carbon fixation during the Calvin cycle. This enzyme is found in the stromal space of the chloroplast. It acts by adding CO2 to the 5-carbon sugar ribulose 1,5-bisphosphate forming 2 molecules of 3-phosphoglycerate.