Answer:
Endosymbiosis can best be described as one organism living completely inside another organism.
Explanation:
Endosymbiosis is referred to a mutually beneficial relationship between two organisms where one organism lives completely inside another organism. The organism which lives inside another one is known as an endosymbiont.
According to the endosymbiotic theory, all eukaryotic cells are evolved from early prokaryotes. Eukaryotes engulf prokaryotic cells capable of aerobic respiration by phagocytosis. The engulfed prokaryotic cells remain undigested and contribute new functionality such as energy production, photosynthesis, etc to the host cell. Eventually, the engulfed cell became an organelle. The organelles such as mitochondria and chloroplasts in eukaryotic cells are considered to have arisen through endosymbiosis.
One example of endosymbiosis includes the relationship between legumes and nitrogen-fixing bacteria (endosymbiont) that live in the root nodules of legumes. The nitrogen-fixing bacteria helps the plants to absorb nitrogen from the soil and plants provide food for the bacteria. The other examples include the relationship between termites and the microorganisms in its gut, single-cell algae living inside corals, etc.
All of the following except __________ developed in some vascular plants and are not present in any nonvascular plants.All of the following except __________ developed in some vascular plants and are not present in any nonvascular plants.
Answer:
Vascular plants have separate tubular tissues such as xylem, phloem for smooth transport of water, minerals and food while non-vascular plants do not show these attributes.
Explanation:
Although both life cycles are divided between the sporophytic and gametophytic generations, vascular plants have a dominant diploid sporophytic phase while non-vascular plants have a dominant haploid gametophytic phase.
Non-vascular plants are poikilohydric (they can withstand dehydration and can recover without any damage to their tissues), though they cannot control the water level in their cells and tissues. On the other hand, vascular plants are homoiohydry. They can survive in any habitat and can control the water content in cells and tissues, though they have low capacity to survive dessication compared to the non-vascular plants.
Non-vascular plants do not have true leaf. The leaves are mere chlorophyll containing. Photosynthesized food are directly sent from one cell to the other. They lack proper transport mechanism for food and water.
On the other hand, the vascular plants have complex multilayered leaf (cells) structure. The waxy layer cuticles on the leaves prevent dessication. That are more chlorophyll containing than their counterpart.
When an _____ occurs the skin usually gets red, swollen and painful
1) respiratory infection
2) inflammatory response
3) vaccination
4) antibody
Answer:
I would guess 2) inflammatory response, as inflammatory refers to burning.
Explanation:
Answer:
B inflammatory response
Explanation:
Two eukaryotic proteins were found to be very similar except for one domain that was very different. Which of the following processes is most likely to have contributed to this phenomenon?
A. multiple random mutations within specific exons of the gene.
B. use of different transcriptional activators.
differential acetylation of specific histone proteins prior to transcription.
C. differences in pre-mRNA splicing that results in an altered pattern of exon inclusion.
D. All of the above.
"The differences in pre-mRNA splicing that results in an altered pattern of exon inclusion" is most likely to have contributed to this phenomenon.
Option: C
Explanation:
The expression of the eukaryotic gene requires several stages and can be regulated by several of them. Different genes are controlled at different locations and it is not unusual for a gene to be controlled at multiple steps, especially a significant or powerful one.
In accessibility of Chromatin the chromatin structure includes DNA and can be regulated by its assembling proteins. More free or 'relaxed' chromatin allows a gene more transcriptible.For many genes transcription is a key regulatory point. Its factor protein sets bind to unique DNA sequences within or near to a gene and encourage or suppress its transcription into an RNA.It is possible to control the splicing, capping, and attaching a poly-A tail to an RNA molecule, and thus exit the nucleus. Specific mRNAs might be produced by alternative splicing from the same pre-mRNA.A 21-year-old female was lost in the woods for several hours. The ambient temperature is 25 degrees Fahrenheit. She is lethargic and confused. The skin on her hands is waxy and white. What should you do
The female should be gently wrapped with dry blankets due to exposure of temperature of about 25 degrees Fahrenheit.
Explanation:
Prolonged exposure to extreme heat or cold conditions can impair the body’s temperature control system.
In the above case the patient is exposed to extreme cold condition in a wood with a freezing temperature of 25 degrees Fahrenheit (-3 degrees Celsius) which leads to hypothermia and frostbite.
Extreme cold conditions can freeze the tissue layers of the parts of the skin exposed like those of the face, hands and feet especially. Due to this the skin becomes white (even grayish yellow or blue) and waxy, cold and numb, and the outer surface may become hard and blistered. There will also be extreme pain, stinging and tingling sensation in the exposed areas.
These changes are mainly due to impaired blood circulation and hypothermia. Hypothermia which is lowering of body temperature causes confusion and lethargy.
The first-aid given for frostbite primarily includes warming the body. The affected person’s body should be covered with warm and dry blankets gently and loosely and any wet clothes should be removed.
So when the body is warmed, the body temperature also will increase and correct the hypothermic symptoms like lethargy and confusion.
A 21-year-old female exhibiting symptoms of hypothermia needs immediate medical attention. She should be gently warmed, provided shelter from the cold, and evacuated to a medical facility as soon as possible. Monitoring her vitals and avoiding exertion are crucial while awaiting rescue.
Explanation:The 21-year-old female lost in the woods and showing signs of lethargy and confusion with waxy and white skin on her hands is likely suffering from hypothermia, a condition where body temperature drops below 95.0°F. Immediate medical assistance is critical, as hypothermia impairs the body's ability to produce heat and can result from various medical conditions like diabetes, infection, and thyroid dysfunction. The symptoms such as confusion and the appearance of skin suggest that she has a severe case and needs to be gently warmed and brought to a medical facility as soon as possible.
It is important to avoid any aggressive warming or massaging of the affected areas, as this can lead to further tissue damage. Instead, if in a remote location, protect her from the cold by moving to a shelter, removing any wet clothing, wrapping her in blankets or dry clothes, and providing warm liquids if she is conscious and able to swallow. Avoid giving alcohol or caffeinated beverages. Monitoring her vitals and readiness for evacuation to a hospital are high priorities. While waiting for rescue, avoiding unnecessary exertion, which can accelerate heat loss, and keeping the person awake and calm are essential strategies.
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle must be involved in this condition
Answer:
Lysosome is the cellular organelle that involved in Tay Sachs disease condition.
Explanation:
This is a rare inherited disorder that occur in the brain due to mutation in HEXA gene that unable to produce beta-hexosaminidase.
This enzyme mainly located in the lysosomes and helps in break down of fatty acid substance called GM2 ganglioside.
Mutation in HEXA gene causes disrupt in the activity of beta hexosaminidase a that prevents enzyme from breaking down into GM2 ganglioside. as a result the toxic level enters into the neuron in the brain and spinal cord and thus causes symptoms of Tay Sachs disease.
Symptoms-
Deafness,progressive blindness,decrease muscle strength,paralysis,seizure,muscular stiffness,slow growth,red spot on macula,increased startle response etc.Tay-Sachs disease is a genetic disorder that results from the absence of a certain enzyme in the lysosome, a cell organelle responsible for breaking down waste materials. This causes a buildup of large, complex, undigested lipids in cells.
Explanation:Tay-Sachs disease is a genetic disorder that involves the buildup of large, complex, undigested lipids, or fats, in cells. The cellular organelle involved in this condition is the lysosome. Lysosomes, often referred to as the cell's waste disposal system, contain enzymes that break down waste materials and cellular debris. In individuals with Tay-Sachs, a specific enzyme in the lysosome is missing, resulting in the accumulation of lipids.
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The boxer crab, Lybia tesselata, carries a small pair of anemones in its claws. When approached by a predator, it waves the anemones around, presenting the stinging tentacles and chasing away the predator. The anemones benefit by eating food particles from prey that the crab catches. What type of relationship is this?
Explanation:
Mutualism is most normally characterized such that mirrors the positive signs describing the result of their cooperations, that is, as connections between people of various species that advantage them two. However, mutualism can be all the more unequivocally characterized as a cooperation between people of various species that outcomes in constructive (useful) consequences for per capita proliferation or potentially endurance of the interfacing populaces. As in other interspecific cooperations, the level of reliance of every mutualist upon different reaches from commit to facultative; henceforth, they can be commit, commit facultative, or facultative–facultative communications.Answer:
Mutualism.
Explanation:
Edmentum.
The phosphorus cycle differs from the carbon cycle in that: A. there is little or no human impact on the phosphorus cycle. B. phosphorus is not a critical component of living organisms. C. plants play a role in the carbon cycle, but have no role in the phosphorus cycle. D. the atmosphere does not contribute to the phosphorus cycle. E. the hydrosphere plays a role in the phosphorus cycle.
Answer: D. the atmosphere does not contribute to the phosphorus cycle.
Explanation:
The phosphorus cycle is different as compared to the carbon, water and nitrogen cycle as the phosphorus element cannot be found in the gaseous state as a result of this the phosphorus cannot be found in the earth atmosphere. The phosphorus can be found in the sedimentary mineral rocks. The weathering process of the sedimentary mineral rocks provides the inorganic phosphorus to the plants. This way the phosphorus cycle begins with the food chain.
Carbon in the form of carbon dioxide, carbon monoxide and other gases can be found in the atmosphere.
The phosphorus cycle differs from the carbon cycle in that the atmosphere does not contribute to the phosphorus cycle, which is not the case with the carbon cycle.
Explanation:The phosphorus cycle differs from the carbon cycle mainly in that the phosphorus cycle does not include a significant atmospheric component. While plants and human activities impact both cycles, the key distinction for the phosphorus cycle is that the atmosphere does not contribute to it, unlike the carbon cycle where the atmosphere plays a major role through processes like photosynthesis and respiration.
Phosphorus is an essential nutrient in living processes, being a crucial part of nucleic acids and phospholipids, and as calcium phosphate, it is a component of our bones. Phosphorus is often the limiting nutrient for growth in aquatic ecosystems, highlighting its importance.
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A species of small lizard has three color forms, pale gray, brown, and black. In its original range, the colors of the rocky environment were mixed from pale gray to very dark, and the population had an even mix of all three color forms. The blending of colors with the environment helps the lizards hide from predators. A group of these lizards ended up on an island with only gray and black rocks. Eventually, the brown lizards disappeared. This is an example of A. directional selection. B. artificial selection. C. stabilizing selection. D. diversifying selection. E. mutation.
Answer:
D. diversifying selection
Explanation:
Diversifying selection, also called disruptive selection, occurs when changes in the environmental conditions act on a population to favor individuals with extreme phenotypes, while individuals with intermediate phenotypes are not favored ad become unfit to survive in the environment.
In the example cited in the question, diversifying section is said to have occurred, as the new environment only helps gray and black lizards to blend with the background color of the rocks, shielding them against predators.Since brown lizards can’t blend with the color of the rocks, they become easily preyed on, and with time,the population of brown lizards disappeared.
If private property rights were established in the air, there would probably be a. more air pollution. b. less air pollution. c. the same amount of air pollution that exists without private property rights in the air. d. better weather.
Explanation:
Air pollution can promote airway inflammation, presenting significantly health dangers for kids with ceaseless respiratory issues. Be that as it may, it is obscure whether this procedure is reversible, with the goal that constraining contamination will profit these kids We estimated the momentary reaction of hypersensitive asthmatic kids presented to a genuine decrease in open-air contamination by utilizing noninvasive biomarkers of aviation route aggravation and capacityHence, the right answer is option b " less air pollution"
Establishing private property rights in the air could lead to b. less air pollution due to the Coase Theorem, which suggests property owners would maintain air quality to protect their asset's value. However, implementation faces substantial enforcement and monitoring challenges.
Establishing private property rights in the air could theoretically lead to b. less air pollution. This is largely based on the Coase Theorem, which suggests that with well-defined property rights, individuals or entities could negotiate the reduction of pollution to balance economic activity and the right to a clean environment. This shift arises because property owners have a vested interest in maintaining the value of their property, including air quality.
Considering the complexities highlighted by Coase, such as monitoring pollution, identifying sources, and managing numerous parties and agreements, enforcement would be a significant challenge. The notion of private property rights in air lends itself to better stewardship but also to complex and costly enforcement and monitoring issues.
If an individual or a group were granted ownership over a portion of the air, they would be motivated to maintain its quality to uphold its value. This could involve negotiating with polluters to reduce or eliminate emissions. However, the practical application of these rights presents substantial obstacles, including the enforcement of agreements and the difficulties in monitoring and proving damage from pollution.
Which of the following would not be a basis for misrepresentation? a. These shrubs will survive in direct sunlight. b. This lawnmower has a safety turn-off switch. c. This soft water system will add five years to the life of your washing machine. d. All of the above are a basis for misrepresentation.
Answer:
i believe your answer is d.
The gene for the MyoD transcription factor is introduced into cultured fat cells. When the gene is expressed, the fat cells are transformed into muscle cells. What does this result imply about the fat cells and their commitment to the fat-cell fate?
Answer:
The result implies that fat cells are committed to this fate, but not irreversibly determined.
Explanation:
The expression of Myod is capable of converting a fibroblast to a skeletal muscle cell. Due to the fact that it can do this, it is therefore a model system in developmental biology for studying how a single initiating event can orchestrate a highly complex and predictable response. Recent findings indicate that Myod functions in an instructive chromatin context and it regulates muscle cell differentiation by inducing cell cycle arrest, a prerequisite for myogenic initiation. The protein is also involved in muscle regeneration. It activates its own transcription which may stabilize commitment to myogenesis.
Ligases are enzymes that link two dna fragments together. Suppose a bacterium develops a mutation in the ligase gene needed for dna replication. This mutation results in an inactive form of the enzyme. What outcome can you expect for this bacterium and why?
Answer:
Cell will not replicate because of incomplete DNA replication.
Explanation:
DNA replication is crucial for reproduction/replication of any organism as it involves the duplication of genetic material. So if an organism is unable to perform proper DNA replication it would not be able to reproduce.
DNA polymerase is the enzyme that synthesize the new DNA strand in DNA replication. DNA polymerase can synthesize a strand only in 5'→3' direction. Both of the strands of DNA molecules are opposite in direction. So one strand is synthesized continuously called as leading strand while the other strand is synthesized in form of okazaki fragments called as lagging strand.
The okazaki fragments are joined together by the enzyme ligase. So if Ligase enzyme is absent in bacteria it would not be able to synthesize the lagging strand of DNA and thus could not be able to produce a replica of DNA. And if there is No replication of DNA then No replication of cell would occur.
Explanation:
The primary role of Ligase enzyme during replication is to ensure repair of DNA fragments,it ensures recombination of the DNA backbone to form double strands back, and ensure joining together of short DNA fragments.
Answer:
Therefore if there is mutation in the bacteria cell, Ligases role is blocked, thus recombination of each strands to form double strands is prevented and the bacteria will not be able to undergo replication, because single strand formed can not be used to undergo replication.
what condition is a major contributor to disability and placement in nursing homes for those over age 75 and is often accompanied by food intake changes?
Answer:
Dementia
Explanation:
Dementia is a condition that involves impaired mental ability and memory which is common among older adults. This condition, which is a major contributor to disability and placement of older adults in nursing homes, can be as a result of several factors of which nutrition has a major role to play. Metabolic and endocrine problem that results to the inability of the body system to regulate nutrients such as calcium and vitamin B-12, are some of the factors that triggers dementia in older adults. Also, nutritional deficiencies such as dehydration, inadequate intake of vitamin B-1, vitamins B-6, copper,vitamin E, and vitamin B-12 increases the chances of developing dementia in older adults.
Research shows that low levels of vitamin D can be linked to increased risk of developing dementia, and as such, supplements such as B-complex vitamin, vitamin C, and vitamin D is usually recommended for the prevention of dementia, especially when they are deficient in the diets taken.
Leslie was diagnosed with type 2 diabetes when his fasting blood glucose level was discovered to be far too high. His ____________ production, which is secreted by the pancreas, was not controlling his blood glucose.
Answer:
INSULIN PRODUCTION
Explanation:
The pancreas is responsible for secreting digestive fluid and juices into the small intestine, this aids digestion of food and absorption into the blood stream.
Also the pancreas secrets insulin into the blood stream. This insulin is responsible for regulating the blood sugar level, or blood glucose levels and enables body cells to absorb glucose that would be broken down to release energy.
Answer:
insulin production
How do phagocytes protect the body?
A. They produce fever, which slows germ growth.
B. They produce mucus that traps germs.
C. They increase blood flow to infected areas.
D. They eat infected and foreign cells.
Answer: They eat infected and foreign cells.
Explanation:
Phagocytes are the cell having ability to ingest foreign cells such as bectaria or dead cells so if any foreigner enter it readily digest it to protect.
What is the name for the new field of study that focuses on the relationship among the brain, immune system, and psychological factors with regard to stress-related events?
Answer:
psyconeur
Psychoneuroimmunology.
Explanation:
This is now known to be the study of the interaction between psychological processes and the nervous and immune systems of the human body. It explains further is the interaction between psychological processes and the nervous and immune systems and stress related events of the human body.
10points
Which of the following happens when infected body cells are detected during a cell-mediated immune response?
Helper T cells divide and activate cytotoxic T cells, which destroy the infected cells.
Memory T cells divide and form helper T cells, which destroy the infected cells.
B lymphocytes divide and activate memory B cells, which destroy the infected cells.
Memory B cells divide and form plasma cells, which destroy the infected cells.
Answer:
destruction of infected cells by cytotoxic T cells, or the destruction of intracellular pathogens by macrophage
Explanation:
A cell-mediated immune response is an immune response that does not involve antibodies. Cell-mediated immune responses involve the destruction of infected cells by cytotoxic T cells, or the destruction of pathogens by macrophages.
The answer cannot be either of the options involving B cells, as these are involved in the antibody response. The cytotoxic T cells are what actually destroy the infected cells (not helper T cells). Therefore, the answer is destruction of infected cells by cytotoxic T cells, or the destruction of intracellular pathogens by macrophage
Answer:
the correct answer is option A
The insects in the order Odonata, including the dragonflies and damselflies, begin life as wingless aquatic nymphs and only later in life emerge as sexually mature, winged adults. If an evolutionary change produced a dragonfly that reached maturity while still in the aquatic stage, this would be an example of __________.
Answer:
Pedomorphosis
Explanation:
Pedomorphosis is a type of evolutionary change that occurs when features or traits that are usually common with the juveniles or larval of an ancestral organisms, become displaced by the adult traits or features in the descendants of that organism. This can either be as a result of slowing down or the acceleration of the physiological development of the organism.
The dragon fly that is produced, which shows features of adult development at its aquatic stage, is an example of Pedomorphosis.
Escherichia coli infections Select one: a. are often transmitted by fecal contaminated water and food. b. include EIEC that destroys gut mucosa. c. involve enterotoxin in traveler's diarrhea. d. are self-limiting with the only treatment being rehydration. e. All of the choices are correct.
Answer:
a. are often transmitted by fecal contaminated water and food.
Explanation:
Eschericia coli belongs to a group of bacteria generally referred to as fecal coliforms because they are of fecal origin.
Hence, their common mode of transmission is through fecal to oral routes such as fecal contaminated food, water and any other substance that passes through the mouth.
E. coli infections can be treated using suitable antibiotics.
The correct option is a.
What are the lines of evidence that Alfred Wegener used to support the idea of continental drift? Why did scientists of his day doubt that continents drifted?
Answer:
Wegener presented a number of evidence to prove his plate tectonic theory, such as :
The matching of rocks on each side of the Atlantic Ocean like a puzzle.His knowledge hat organisms such as freshwater reptiles were found in almost all continentsHe also identified organisms that live in different continents, and could not possibly cross over to the other continents due to water bodies (oceans) separating the continents.Wegener's plate tectonic theory caused doubts to other scientists, because of the way he presented his evidence. Other scientists considered his mechanisms unrealistic
Explanation:
Alfred Wegener supported the idea of continental drift with evidence like the jigsaw-like fit of the continents, similarity of fossils, geological features, and paleoclimatic signs found on different continents. His theory was doubted by scientists of his time due to lack of a sufficient explanation for what could cause such a drift.
Explanation:Alfred Wegener proposed the theory of continental drift in the early 20th century. He used several lines of evidence to support his theory.
Fit of the continents: Wegener observed that continents seemed to fit together like a jigsaw puzzle, suggesting they were once joined and later drifted apart.Fossil evidence: Similar fossils were found in different continents that are now separated by oceans. This suggests these areas were once linked and shared a common environment.Rock formations and geological features: There are similar rock stratification patterns and geological structures found on separate continents, implying a shared formation history.Paleoclimatic Evidence: Wegener discovered evidence of tropical plants in Arctic regions and glacial deposits in tropical regions, suggesting that continents had moved from their original positions.Despite Wegener's substantial evidence, many scientists of his time doubted the theory of continental drift. This skepticism primarily arose due to lack of a credible explanation for the mechanism that could cause continents to drift. It was only decades later, with the development of plate tectonic theory, that Wegener’s ideas became widely accepted.
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Which of the following are current applications of microsystem technology in modern automobiles (three best answers): (a) air-bag release sensors, (b) alcohol blood level sensors, (c) driver identification sensors for theft prevention, (d) oil pressure sensors, (e) temperature sensors for cabin climate control
Answer:
The current applications of microsystem technology in modern automobiles includes;
(a) air-bag release sensors
(d) oil pressure sensors
(e) temperature sensors for cabin climate control.
Explanation:
Microsystem Technologies examines electromechanical, materials, design, and manufacturing issues of microsystems and their components.
Within the automotive industry, micro-electro-mechanical-systems (MEMS) technology has contributed to the improved performance, reliability and lower-cost sensors that support basic automobile functions, including driving, turning, and stopping.
Microsystem technology includes; LIGA technology, microelectromechanical systems and micromachines
Which phylum includes the most basal lineages of animals?
Answer:
Porifera (sponges)
Answer: Porifera
Explanation: Sponges, the members of the phylum Porifera, are a basal Metazoa clade as a sister of the Diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells
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Which of the following processes produces the most ATP per molecule of glucose oxidized? Group of answer choices aerobic respiration lactic acid fermentation alcoholic fermentation All produce approximately the same amount of ATP per molecule of glucose.
Explanation:
Respiration is the metabolic process of most living things in which food molecules or glucose are turned into usable energy for the cell, called ATP. Respiration is the anti-process to photosynthesis, the process in which plants use sunlight and carbon dioxide to build food molecules releasing oxygen as a waste productDuring aerobic respiration, oxygen is present and helps the process to crank out energy very efficientlyIt all starts with sugar An organism takes in carbohydrates for energy, and the digestion process breaks the carbs down into their smallest units, glucose, a type of sugar molecule. Cells then make energy by breaking the glucose molecule down and releasing its electrons, which are later used to help crank out ATPThe following processes produce the most ATP per molecule of glucose oxidized - aerobic respiration.
Aerobic respiration:A total of 36 ATPs are produced from aerobic respiration for each glucose2 from glycolysis2 from the citric acid cycle32 from ETP).Lactic acid fermentation:A total of 2 ATPs are produced from it.Lactic acid fermentation has two steps: glycolysis and NADH regeneration.During glycolysis, one glucose molecule is converted to two pyruvate molecules, producing two net ATP and two NADH. Alcoholic fermentation:Alcoholic fermentation occurs in yeast and produces ethanol and carbon dioxide.Fermentation only produces two ATP per glucose molecule through glycolysisThus, The following processes produce the most ATP per molecule of glucose oxidized - aerobic respiration.
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With the endosymbiotic hypothesis in mind, what structure within modern-day chloroplasts is likely derived from the cytoplasm of an ancestral cyanobacterium that took up residence within a eukaryotic cell?
Inner membrane of the chloroplasts
Explanation:
The present day eukayrotes are all considered to be derived from its original ancestor – the cyanobacteria.
Earlier, photosynthesis by the first photoautotrophs took place utilizing hydrogen sulphide as the electron donor. However, it was later when the cyanobacteria, which were originally residing in the mitochondria of an eukaryotic cell under an endosymbiotic relationship, developed into true chloroplasts, the use of water as electron donor to perform photosynthesis began.
The cyanobacteria were aerobic in nature and required oxygen to survive. They evolved the chloroplasts covered with an external protective membrane and an internal membrane. It is the internal membrane which contains all the necessary organelles or components necessary for photosynthesis like thyllakoids, stroma etc which helped them to utilize water as an electron donor during photosynthesis like all the eukaryotes.
Final answer:
The thylakoid membrane system within chloroplasts is likely derived from the cytoplasm of an ancestral cyanobacterium. Supported by the endosymbiotic hypothesis, chloroplasts show evidence of a double membrane indicative of their symbiotic origins with an ancestral eukaryotic host.
Explanation:
Within modern-day chloroplasts, the structure that is likely derived from the cytoplasm of an ancestral cyanobacterium is the thylakoid membrane system. These membranes are the site of the light-dependent reactions of photosynthesis. The endosymbiotic hypothesis, primarily attributed to Lynn Margulis, holds that plastids, including chloroplasts, originated as cyanobacteria taken up by an ancestral eukaryote through primary endosymbiosis. The chloroplasts are characterized by their double membrane, reflecting this endosymbiotic origin. The inner membrane is thought to have originated from the cyanobacterial plasma membrane, while the outer membrane likely came from the engulfing vacuole of the host cell. Additionally, chloroplasts retain a circular DNA structure and ribosomes closely resembling those of cyanobacteria, providing further evidence of their endosymbiotic origins.
In the epinephrine pathway, an inhibitor of phosphodiesterase activity would have which of the following effects? A. block the activation of protein kinase A B. block the activation of G proteins in response to epinephrine binding to its receptor C. prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm D. block the response of epinephrine
Answer: C). prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm
Explanation: In the epinephrine pathway, binding of epinephrine to its receptor triggers a conformational change in the receptor and the interaction of the receptor with its associated Gs protein. This interaction causes the replacement of GDP bound to Gs protein with GTP thus activating the Gs protein. The activation of the Gs protein causes the alpha subunit of the Gs protein to dissociate and move to adenylyl cyclase, another membrane protein in the pathway. The association of the alpha subunit of the Gs protein with adenylyl cyclase activates adenylyl cyclase which in turn catalyzes the synthesis of cyclic AMP (cAMP) a second messenger. cAMP is quickly degraded to 5'-AMP by an enzyme phosphodiesterase. Inhibition of the activity of phosphodiesterase will increase the half life and the cytoplasmic level of cAMP thus potentiating the action of epinephrine.
All four possible reactions in the animation are energetically favorable; the energy of the four products is lower than the energy of the original starting molecule. Why does the starting molecule not completely and quickly convert to its possible products before the addition of heat or an enzyme?
Answer:
Starting molecules not completely and quickly convert to its possible product because an activation energy barrier exist that must be overcome for conversion to product.
Explanation:
The activation energy of a chemical reaction is closely related to its rate. This is because molecules can only complete the reaction once they have reached the top of the activation energy barrier. The higher the barrier is, the fewer molecules that will have enough energy to make it over at any given moment.
Many reactions have such high activation energies that they basically don't proceed at all without an input of energy. For instance, the combustion of a fuel like propane releases energy, but the rate of reaction is effectively zero at room temperature. Once a spark has provided enough energy to get some molecules over the activation energy barrier, those molecules complete the reaction, releasing energy. The released energy helps other fuel molecules get over the energy barrier as well, leading to a chain reaction.
Dayton's pupils are dilated and his heart is pounding immediately after he gets terrified by a large groundhog running across his driveway after he parks his car. His _____ nervous system is activated. parasympathetic afferent sympathetic efferent
Answer:
Sympathetic Nervous system
Explanation:
The sympathetic nervous system is the part of the nervous system that is responsible for "Fight or flight" reactions.
Beatrice was born without cone cells in her retina. What effect will this most likely have on her vision? She will be unable to see out of the side of her eyes. Her vision will be unaffected. She will be colorblind. She will be completely blind.
Answer:
The answer is, she will be colour blind.
Explanation:
If cone cells are not present in a person's retina, they cannot see colours in the day.
Rods and Cones are photo receptors in human retina. Rods allow us to see during low light. they have low spatial acuity and do not mediate colour vision. If rods are not present, she would have night blindness.
Cones are capable of having colour vision. They are active at the higher light levels.
Rods and Cones are photo receptors, but with cones specifically, if they are not there then we would not be able to distinguish colours. This condition is referred to as colour blindness.
When you are on a first date, your hands begin to sweat, and you begin to feel nervous. What theory of emotion would say that the sweating caused the nervousness?
Final answer:
The James-Lange theory of emotion suggests that physiological arousal, such as sweating hands, precedes and causes emotional experiences like nervousness. This theory indicates a direct link between physical changes and emotional states.
Explanation:
The theory of emotion that would say that the sweating caused the nervousness on a first date is the James-Lange theory of emotion. According to this theory, emotional experiences arise from physiological arousal. So in the case of a first date, the theory would suggest that the physical sensations of sweating hands are what lead to the feeling of nervousness.
The James-Lange theory posits that different patterns of arousal are associated with different emotions. For instance, if you encounter a venomous snake, your sympathetic nervous system would trigger arousal, such as increased heart rate and respiration, and you would only experience fear after these physical changes occur.
Contrastingly, the Schachter-Singer two-factor theory suggests that both physiological arousal and cognitive appraisal of the context are necessary to experience emotion. According to this theory, it's the cognitive interpretation of the physiological arousal in the context of the situation that leads to the feeling of being nervous.
In at least one paragraph (3-5 sentences), discuss the 3 types of asexual reproduction that are used by fungi. Your response should be in your own words with proper grammar and mechanics.
Answer:
Fungi can reproduce sexually, as well. This process involves mating between opposite types of fungi; the types are known as (+) and( -). Afterwards, the nuclei can fuse together to form a diploid zygospore that develops upward through meiosis. Since there are two organisms included in this method of reproduction, genetic variability is made possible.
Explanation: