Answer:
They would use PCR to amplify the DNA.
Explanation:
PCR or Polymerase Chain Reaction, using a thermostable enzyme, Taq Polymerase. It is a molecular biology technique, whose objective is to obtain a large number of copies of a DNA fragment of interest, starting from a minimum. It is done in a thermal cycler.
This technique serves to amplify a DNA fragment; after amplification it is much easier to identify with a very high probability, virus or bacteria causing a disease, identify people or do scientific research on amplified DNA.
To examine degraded DNA from a 30-year-old homicide case, technicians would use PCR to amplify DNA with possible follow-up through RFLP analysis for DNA fingerprinting, which is crucial for identifying the source of the forensic sample. So the correct option is B.
Explanation:Cold case detectives investigating a 30-year-old homicide case would likely use Polymerase Chain Reaction (PCR) to amplify the degraded DNA found in a tiny blood sample on the victim's clothing. PCR is a powerful technique that can increase the quantity of specific DNA sequences for further analysis, making it possible to work with the small and degraded samples typical of old cases. PCR is used in conjunction with restriction fragment length polymorphism (RFLP) analysis to generate DNA fingerprints. While Option A (using restriction enzyme and DNA ligase to make recombinant DNA) could be part of this process, it is more typical to use PCR and RFLP, and Option C (using RT-PCR) is not relevant for this case as it is used to study gene expression, not to amplify DNA from a forensic sample.
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What type of division (meiosis or mitosis) does the diploid zygote of an animal have to go through (usually many times) in order to give rise to all of the cells in the adult body?
Answer:
Mitosis
Explanation:
A zygote is a fertilized egg. This zygote needs continuous growth in order to develop into a grown adult. The growth involves generating new somatic or body cells through cell division. A parent cell in the zygote divides to produce identical copies of itself. This way, genetic information is passed on the the new arising daughter cells. To do this, the parent cell must first replicate its DNA and the process of separating this duplicated DNA into two identical cells is known as mitosis.
Mitosis is a type of cell division that involves the production of daughter cells that are genetically identical copies of the parent cell and also the same number of chromosomes as the parent cell.
As cells divide, duplication occurs. As cell multiplies, growth is occurring in the organism. The zygote keeps undergoing growth division (mitosis) till it gives rise to all the cells in an adult.
On the other hand, Meiosis is also a type of cell division but it is a division mainly involved in reproduction not growth. Reproductive cells divide to give rise to daughter cells (gametes) that have a reduced number of chromosomes.
An important difference between glycosidic linkages in polysaccharides and the linkages between monomers in proteins and nucleic acids is _____.
Answer:
the location and geometry
Explanation:
Proteins and nucleic acids are formed between the same locations in the monomers, but this is not true for glycosidic bonds.
The location and geometry of the glycosidic bonds can vary greatly between polysaccharides and can sometimes produce branched chains that are not seen in nucleic acids or proteins.
An important difference between glycosidic linkages in polysaccharides and the linkages between monomers in proteins and nucleic acids is cellulose.
Explanation:An important difference between glycosidic linkages in polysaccharides and the linkages between monomers in proteins and nucleic acids lies in the nature and function of these bonds.
Polysaccharides, such as cellulose, glycogen, starch, and chitin, are composed of monosaccharide monomers linked together by glycosidic bonds, which could be α-1,4, β-1,4, or α-1,6 glycosidic linkages, depending on the type of the polysaccharide. These bonds contribute to the structural properties and biological functions of these polysaccharides.
On the other hand, monomers in proteins and nucleic acids are linked together by peptide bonds and phosphodiester bonds respectively. A peptide bond is a covalent bond between two amino acids, while a phosphodiester bond is a type of covalent bond that occurs between the sugar of one nucleotide and the phosphate of the next.
These bonds play a vital role in the formation of the secondary, tertiary, and quaternary structures of proteins and the double-helix structure of DNA.
Therefore, glycosidic linkages in polysaccharides and the linkages in proteins and nucleic acids are different in their chemical nature, function, and contribution to the structure and properties of these large macromolecules.
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While attempting to capture the scorpion, the mouse's heart rate increases, and there is an increase in epinephrine in the mouse's blood. What nervous system division is responsible for the mouse's physiological state? Please use the following information to answer the questions below. The southern grasshopper mouse feeds regularly on the Arizona bark scorpion, the most venomous scorpion in the United States. While attempting to capture the scorpion, the mouse usually gets stung multiple times by the scorpion but does not seem to be affected. While attempting to capture the scorpion, the mouse's heart rate increases, and there is an increase in epinephrine in the mouse's blood. What nervous system division is responsible for the mouse's physiological state?a.sympatheticb.parasympatheticc.sensoryd.enteric
Answer:
a. sympathetic nervous system
Explanation:
The sympathetic nervous system is part of the autonomic nervous system that is specifically responsible for the “fight or flight” response of the body when exposed to stress or threat. These responses to danger or stress are often involuntary. It is characterized with increased heart rate, constriction of blood vessels, profuse sweating, increased blood pressure etc.
When the sympathetic nervous system is activated in he presence of stress or a threat, epinephrine is released, initiating various reactions in the body against such threat or stimulus.
The mouse's increased heart rate and high epinephrine level during scorpion hunting is controlled by the sympathetic division of the autonomic nervous system, which drives the 'fight or flight' response.
Explanation:The physiological state of the mouse, characterized by high epinephrine levels and a high heart rate while hunting the scorpion, is primarily governed by the sympathetic division of the autonomic nervous system. This part of the nervous system enacts the "fight or flight" response, mobilizing the animal's resources to respond to threatening situations. Functions controlled by the sympathetic nervous system include faster heart rate and inhibited digestion, all aiming to prepare the organism for physical strain required to confront danger or escape it.
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What genere of games involves gameplay that is designed to simulate real-world or fictionalized activities such as flying a plane or managing a city and often requires resource management?
Answer: The answer is Simulation Games
Explanation:
Simulation games are games that are designed to imitate or closely simulate real-world life activities. The players are able to control characters in the game, they are provided with a simulated environment in which they can play. The characters in the game copy real life activities such as flying a plane, managing a city as listed in the question, cooking, interacting with others, attending school or going to work, etc.
The genre of games that simulate real-world or fictional activities and require resource management is known as simulation games, including the likes of Second Life and Civilization.
Explanation:The genre of games that involves gameplay designed to simulate real-world or fictionalized activities, such as flying a plane or managing a city, and often incorporates elements of resource management, is typically known as simulation games. These games offer a sense of realism and challenge players to think strategically and make decisions as if they are in a real-life situation. Examples of simulation games include city-building games, flight simulators, and life simulation games like Second Life, wherein players create avatars and interact in a virtual world.
Simulation games can vary in complexity and scope. Some simulate a narrow set of activities, like running a farm in Farming Simulator, while others provide a broader canvas like managing an entire civilization in Civilization. The business models for such games can also be quite diverse, with some offering in-game purchases for virtual goods, which has turned playing into a potential source of income for some, as evidenced by the trend of buying, selling, and managing online assets for real money.
"In Graves disease, thyroid-stimulating immunoglobulins (TSI) contain an active site that can mimic the active site of TSH to stimulate thyroid hormone production. One would expect TSI to cause:"
The question is incomplete. The complete question is:
"In Graves disease, thyroid-stimulating immunoglobulins (TSI) contain an active site that can mimic the active site of TSH to stimulate thyroid hormone production. One would expect TSI to cause:"
A. An increase in thyroid gland size because of the trophic effect of TSH.
B. A decrease in thyroid gland size because of competitive inhibition with TSH.
C. No change in thyroid gland size because antibodies only recognize foreign particles.
D. An immune response against TSH molecules.
Answer:
A. An increase in thyroid gland size because of the trophic effect of TSH.
Explanation:
Thyroid-stimulating hormone is a trophic hormone and is released by the anterior pituitary gland. It targets the thyroid gland and stimulates it to release the thyroid hormones. Graves disease is an autoimmune disorder in which the person produces antibodies such as thyroid-stimulating immunoglobulins that mimic the action of thyroid-stimulating hormone (TSH).
These antibodies continually stimulate the thyroid gland to grow and produce thyroid hormones. The result is an abnormally enlarged thyroid gland. The affected individuals also develop peculiar edema behind the eyes that causes the eyes to protrude.
Blood types are determined by the presence of protein located on
Answer:
Red blood cells.
Explanation:
Our blood is made up of blood cells and plasma which is an aqueous fluid. Blood type is determined by the identifiers presence and absence which is present on the surface of red blood cells. These identifiers are known as antigens which helps in the immune system to identify its own red blood cell types.
There are 4 types of blood type:
A, B, O, and AB. These blood types are determined with the help of the antigen which is present on the surface of the blood cell and antibodies which is present in the plasma.
Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome.If she moves the repressor gene (lacI), along with its promoter, to a position at some several thousand base pairs away from its normal position, we would expect the _____.repressor will no longer bind to the operatorlac operon will be expressed continuouslylac operon will function normallyrepressor will no longer bind to the inducerrepressor will no longer be made
Answer:
The correct option is lac operon will function normally.
Explanation:
The promoter region can be described as a region due to which transcription begins for a certain gene. Promoters can be present near to the gene for which they initiate transcription or they might be present several sequences away upstream.
The promoter region will still be able to initiate transcription several base pairs away hence the lac operon will function normally. The repressor will also detect the promoter and function normally.
Two populations of mice exist on either side of a river. After a bridge is constructed across the river, the two populations come to resemble each other more.
What is the most likely explanation for this?
A) Stabilizing selection
B) Directional selection
C) Gene flow
D) Genetic drift
E) Nonrandom mating
Answer:
C) Gene flow
Explanation:
Gene flow refers to the movement of alleles between local populations. It results from the migration of individuals. Two adjacent populations can exhibit gene flow due to the mating between their individuals and can have significant evolutionary consequences as it does not allow the reproductive isolation of these populations. In the given example, the two mice populations are present on either side of a river. Mating between the mice of the two populations resulted in gene flow and maintained resemblance among their members.
After finishing six pieces of toast with butter, Sally prepares a batch of brownies while eating large bowls of ice cream, yogurt, and cottage cheese. She then eats half a bag of cookies, an entire pizza, and three baked potatoes, even though she does not feel hungry. After eating, she feels guilty, ashamed, and sad but does not vomit or make any other efforts to eliminate the calories she consumed. Sally appears to meet criteria for
a. anorexia nervosab. bulimia nervosac. binge-eating disorderd. restrictive dieting
Answer: Binge-Eating Disorder
Explanation: Sally did not vomit the food away, and she ate way too much food in a short amount of time, which would be Binge-Eating Disorder.
Almeda’s skin has lost some flexibility and the lens of her left eye is beginning to cloud. She is concerned that the normally separate protein fibers that make up her body’s connective tissue are forming bonds with one another. You can tell Almeda that she can reduce cross-linking by: .
Answer: Eating a healthy diet
Explanation:
Connective tissue is characterized by varying amounts of extracellular matrix, which surrounds various cell types. This tissue is also called support tissue, since it is related to the epithelial and muscular tissues to which it gives support and fills the spaces between cells and organs. Also, the eye's outer layer is made of dense connective tissue, which protects the eyeball. In addition, the connective tissue transports nutrients from the blood capillaries to the various tissues and, conversely, also mobilises waste products from metabolism into the blood.
There are many protein fibers found in connective tissues such as collagen which provide strength to the tissue, preventing it from being torn. So, formation of connective tissue proteins like is affected by a nutrition deficiency.
A healthy, balanced diet, including the proper amounts of protein, can prevent the skin and vision problems she has.
Which of the following is a characteristic of diabetic ketoacidosis (DKA)?
Select all that apply.
a. More common in type 1 diabetes
b. Normal arterial pH level
c. Rapid onset
d. Absent ketones
e. Elevated blood urea nitrogen (BUN) and creatinine
Answer:
The answers are: a. More common in type 1 diabetes, c. Rapid onset and e. Elevated blood urea nitrogen (BUN) and creatinine.
Explanation:
These three factors are very characteristic of diabetic ketoacidosis. Mostly the elevated blood urea nitrogen and creatinine, that can be fastly detected with urine tests.
Reversible lanes are marked with unique signs, signals and markings, such as_____.
A) a flashing yellow X, which means use this lane ONLY for a right turn
B) a solid yellow X, which means stay in the lane but slow down
C) a red X, which means the lane is closed
D) a flashing red X, which means to prepare to stop
Answer:
Option A
Explanation:
The reversible traffic lanes are a regulatory tool/mechanism to control the traffic in rush hour where the directions of traffic are kept opposite to each other at a particular time of the day. So, symbolically they are represented by pavement markings along with special lane signals, symbols, and sign which are as follows –
a) Solid white line marking the edge of the pavement
b) Stop lines, crosswalks and parking spaces are marked by white lines
c) Symbols in white color
d) Single yellow line marks to highlight the left edge of one-way road and all divided road.
e) Yellow-colored marked curbs
f) Central lane marking arrow
Hence, option A is correct
Answer: Option C
Explanation:
According to the safety guidelines the roads that are closed is marked with red lines in order to let the people known that the road is closed and there is a reversible lane which should be opted by the people.
The reversible lane is a lane which is made in order to make travel in either directions. When there is a rush hour there is a a proper display of signals in order to show closed driving or turning.
There is a red X made on the lane when the road is closed and is not available for use.
Enchanted Rock State Natural Area is located in Central Texas. Enchanted Rock is a dome of granite. The area contains four easily identifiable communities. The table describes characteristics of each type of community in the area.
A student studying primary succession should focus on which of these communities?
A)
Open oak woodland
B)
Mesquite grassland
C)
Floodplain
D)
Granite rock
Answer:
D) Granite rock
Explanation:
Enchanted Rock is a dome of granite, so you would pick this answer choice.
I am joyous to assist you anytime.
For primary succession studies, focus on the Granite Rock community at Enchanted Rock State Natural Area. This demonstrates how life begins in an area with no soil or living organisms.
Explanation:A student studying primary succession should focus on the Granite Rock community at the Enchanted Rock State Natural Area. Primary succession is a sequence of ecological changes whereby life forms begin to inhabit an environment that previously had no life - typically a bare rock surface, like granite. In short, it's how life begins in an area with no soil or living organisms, therefore the Granite Rock community is the perfect example of primary succession happening as lichens and mosses break down the rock to form soil, promoting growth of more complex plant life.
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A client with muscular dystrophy has lost complete control of his lower extremities. He has some strength bilaterally in the upper extremities, but poor trunk control. Which mechanism would be the most important to have on the wheelchair?
a) Wheelchair belt
b) Antitip device
c) Headrest support
d) Extended breaks
Answer:
The “wheelchair belt” mechanism is the most important mechanism to have on the wheel chair.
Explanation:
As the patient have very poor control over his trunk so a belt will be perfect to prevent him from falling out of the wheelchair anytime. The other options doesn’t make much of important sense than a belt for the patient with muscular dystrophy needs, especially when lost control over the extremities. The wheelchair belt will help him in staying in the wheelchair freely without risk of falling off.Parietal cells of the gastric glands in the stomach produce
Answer:
HCL and intrinsic factor
Explanation:
The oxyntic cells/ delomorphous cells also called as parietal cells. The cells are present in the gastric glands the fundus lining and cardia. These parietal cells are the epithelial cells. The cells secretes intrinsic factor and HCL (hydrochloric acid).
The hydrochloric acid secreted helps in converting inactive pepsinogen to active enzyme pepsin. This helps to break bond between amino acids. This process is called proteolysis. The intrinsic factor helps in vitamin B12 absorption from the intestine and absence of this factor is responsible for pernicious anemia.
Final answer:
Parietal cells in the stomach's gastric glands produce hydrochloric acid, which contributes to the stomach's acidity and activates digestive enzymes, and intrinsic factor, which is necessary for vitamin B12 absorption.
Explanation:
The parietal cells of the gastric glands are primarily located in the middle region of the gastric glands in the stomach. They are highly differentiated epithelial cells responsible for secreting both hydrochloric acid (HCl) and intrinsic factor. Hydrochloric acid plays a crucial role in maintaining the stomach's high acidity, with a pH range of 1.5 to 3.5, enabling the activation of pepsin, an enzyme crucial for protein digestion. The acidity also acts as a protective barrier by killing ingested bacteria and denaturing proteins for easier digestion. Intrinsic factor, on the other hand, is vital for the absorption of vitamin B12 in the small intestine, important for preventing pernicious anemia.
An individual accidentally transected (cut across) the spinal cord between T1 and L1. This would result in ________. An individual accidentally transected (cut across) the spinal cord between T1 and L1. This would result in ________.
paraplegia
quadriplegia
spinal shock
only hemiplegia
Answer:
a. paraplegia
b. paraplegia (it is repeated)
Explanation:
• Paraplegia T1-T9 (Requires assistance at least 3 hours a day). People with lesions from T1 preserve innervation and, therefore, the function of all upper limb muscles. They can achieve functional independence, not only in self-care and mobility activities, but also in certain light domestic activities. From this level of injury, an intensive training to carry the manual wheelchair through irregular terrain, slopes and ramps is feasible. From the T6 lesion the patients present a better trunk control. In addition, with proper training, they can make transfers from the floor to the chair. People with injuries between T2 and T9 can achieve prophylactic standing with parallel bitters, with the support of a walker or crutches.
• Paraplegia T10 L1 (Requires assistance at least 2 hours a day) Patients with injuries from T10 have normal breathing with normal vital capacity. As with T1-T9 lesions, they are independent in activities of daily living, sphincter care and transfers. This group of patients is able to perform independent standing and assisted therapeutic walking. Unfortunately for all these activities, energy expenditure is excessive and joint wear of the upper limbs is important. Patients remain dependent on a self-propelled wheelchair for travel.
What minerals are formed when shale and basalt are exposed to low grade metamorphism
Answer:
Slate and Analcime minerals are formed when shale and basalt are exposed to low grade metamorphism.
Explanation:
As a result of metamorphosis of clay, shale and basalt a fine grained rock is formed that is unique slate texture. Slate is formed by low grade metamorphosis i.e low temperature and pressure.Slates are the older rocks perhaps in some places the recent formation can also be seen. It can be of various colours like black, blue, purple, red, green and grey.
Dark colour of the slate is due to the presence of more carbon material. Analcime is a white, colourless or can be grey tecto-silicate mineral. It consist of hydrated sodium aluminium silicate in cubic crystalline form. Analcime is similar to that of zeolite mineral with which it is sometime classed
Final answer:
Shale and basalt exposed to low grade metamorphism typically form minerals such as chlorite, muscovite, and biotite, while rocks like chlorite schist, mica schist, and amphibolite might be produced. The presence of index minerals like chlorite and kyanite can help determine the metamorphic grade and the pressure-temperature conditions of the rock.
Explanation:
When shale and basalt are subjected to low grade metamorphism, several new minerals can form as a result. With shale as the parent rock, we often see the development of minerals such as chlorite, muscovite, and biotite, which can lead to the formation of rocks like chlorite schist or mica schist. Furthermore, if garnets are present, a mica-garnet schist may be formed. On the other hand, when basalt undergoes low-grade metamorphism, chlorite and amphibole minerals are often prevalent, leading to the creation of chlorite schist or amphibolite. Index minerals such as chlorite and muscovite are indicative of the metamorphic grade experienced by these rocks.
During metamorphism, certain index minerals act as indicators for the temperature and pressure conditions. For shale-derived rocks, these index minerals may include garnet, staurolite, sillimanite, kyanite, and andalusite. The presence of kyanite and sillimanite usually indicates medium-pressure conditions, often associated with continent-continent collision, whereas andalusite together with sillimanite suggests low-pressure terranes, possibly in areas of divergent tectonic zones or unique ocean-continent collisions.
Identify the muscular structure that anchors the lens in place.
Answer:
ciliary body
Explanation:
The association of ciliary muscles known as ciliary body is responsible for keeping the lens at its right position. Ciliary is circular structure which is just extension of iris. Ciliary muscles regulate the shape of eye lens in order to clearly focus on objects.
There are three layers ciliary bodies or IRIS
a) Endothelium,
b) Stroma
c) Epithelium.
The ciliary muscle, part of the ciliary body, is the muscular structure in the human eye that anchors the lens in place. It adjusts the lens's shape for near or distant vision through a process called accommodation.
Explanation:In regards to the anatomy of the human eye, the muscular structure that anchors the lens in place is known as the ciliary muscle. This muscle is part of the ciliary body, which also comprises the ciliary processes. When the ciliary muscle contracts or relaxes, it alters the shape of the lens, thus adjusting the eye's focus for near or distant vision. This phenomenon is known as accommodation.
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Why is energy lost when herbivores eat primary producers?
Herbivores lose energy when they eat primary producers due to the second law of thermodynamics and the conversion of energy to metabolic heat.
Explanation:Energy is lost when herbivores eat primary producers due to the second law of thermodynamics, which states that energy is lost whenever it is converted from one form to another. As organisms consume other organisms, a significant amount of energy is lost as metabolic heat. This results in a decrease in the amount of energy available to the herbivores at the next trophic level, which impacts the overall energy flow in the ecosystem.
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Bacteria and humans use the same DNA components, and both kinds of cells also perform transcription and translation. Which of the following choices is a potentially significant outcome of this shared mechanism?
a) Bacteria are able to transcribe and translate human DNA. thus, they could evolve into human's
b) Bacteria are able to transcribe and translate human DNA. and thus, they potentially could produce human proteins
c) Bacterial and human proteins are identical in amino acid sequence because the mechanism for producing them is the same
d) Bacterial and human DNA are identical in sequence because the method for producing them is the same
Answer:
The correct answer is b) Bacteria are able to transcribe and translate human DNA. and thus, they potentially could produce human proteins.
Explanation:
Bacteria could produce human proteins, but they don't need them, so their physiological mechanism produces only the proteins and secondary metabolites needed.
Bacteria can transcribe and translate human DNA due to the shared machinery between bacterial and human cells, allowing the potential production of human proteins in bacterial systems. This similarity supports the concept of common ancestry and is applied in biotechnology, such as the synthesis of human insulin in E. coli.
Explanation:The potentially significant outcome of the shared mechanism of transcription and translation between bacteria and humans is b) Bacteria are able to transcribe and translate human DNA, and thus, they potentially could produce human proteins. This shared genetic machinery allows for the possibility of expressing human proteins in bacterial cells, which is a foundational principle in the field of recombinant DNA technology. The commonality in cellular machinery is evidence of a common ancestor and underlies many modern biotechnological applications, like the production of insulin using E. coli. It's important to note that, although the mechanisms for DNA replication, transcription, and translation are similar, this does not mean that bacterial and human proteins are necessarily identical in amino acid sequence or that bacterial and human DNA are identical in sequence, as each organism has its own unique genetic code that specifies its individual protein sequence.
Bacterial ribosomes and the mechanism of protein synthesis share similarities with eukaryotic systems, which supports the idea of common ancestry. Additionally, both prokaryotic and eukaryotic cells follow the central dogma of molecular biology, where genes along the DNA are transcribed into RNA and then translated into proteins. Although ribosomes in bacteria are slightly different in size compared to those in eukaryotic cells, they are functionally similar and capable of translating eukaryotic mRNA in certain conditions.
What is located in the postcentral gyrus of the parietal lobe?
Answer: The primary somatosensory cortex is located in the post central gyrus of parietal lobe.
Explanation:
Post central gyrus is the gyrus of the parietal lobe which is one of the four major lobes of the human brain that house the primary somatosensory cortex which is the main receptive area for sense of touch. There is a map of sensory space found in this area called the sensory homunculus.
Contraction of a sarcomere, and thus contraction of the muscle as a whole, is accomplished by a cyclic sequence of interactions between actin (thin filaments) and myosin (thick filaments) in the sarcomere. Understanding this sequence of events is essential to understanding the mechanism of muscle contraction at the cellular and molecular levels.
Begin by considering a relaxed muscle. In this state, the myosin molecules of the thick filaments are not in contact with the actin of the thin filaments, and ADP and Pi are bound to the myosin heads. An action potential on the muscle cell plasma membrane initiates contraction of the sarcomeres from this relaxed state.
Rank the following events in the sequence in which they occur, beginning with myosin forming a cross-bridge with actin.
A) Myosin head forms a cross-bridge with actin
B) Myosin releases Pi
C) Myosin pulls actin toward center of sarcomere
D) Myosin binds ATP
E) Cross-bridge between myosin and actin is broken
F) Myosin hydrolyzes ATP to ADP and Pi
G) Myosin head extends.
Muscle contraction starts with the formation of a cross-bridge between myosin and actin. Pi is released, actin is pulled towards the center of the sarcomere, and the cycle continues. Hence the correct answer is option E
Explanation:The sequence of events in muscle contraction begins with the formation of a cross-bridge between the myosin head and actin. This is followed by the release of Pi and the pulling of actin towards the center of the sarcomere by the myosin head. Next, the myosin binds ATP, which leads to the breaking of the cross-bridge between myosin and actin. The myosin head then extends, and the cycle continues.
Hence the correct answer is option E
The crown-of-thorns sea star, Acanthaster planci, preys on the flesh of live coral. If coral animals are attacked by these sea stars, then what actually provides nutrition to the sea star, and which chemical (besides the toxin within their nematocysts) do the corals rely on for protection?
A) medusae; silica
B) polyps; silica
C) exoskeleton; calcium carbonate
D) polyps; calcium carbonate
Answer:
d) polyps; calcium carbonate
Explanation:
The Acanthaster planci It is a kind of invasive starfish, which destroys corals: it has poisonous spines and feeds on coral polyps at the expense of the reef.
On the other hand, CO2 reacts with water, forming carbonic acid and reducing the available calcium carbonate, an essential element so that marine organisms, from clams to hedgehogs, can form their skeletons and shells.
Answer: The correct answer is : D) polyps; calcium carbonate
Explanation: This starfish feeds exclusively on hard corals. It can be brown, dark gray, purple, orange or red, the difference in color lies in the food they eat. It has its body covered with thorns that uses them as a means of defense.
Which of the following disorders affects men and women in equal numbers and is characterized by a chronic, progressive chorea (involuntary and irregular movements that flow randomly from one area of the body to another)?a. Huntington's diseaseb. AIDSc. Alzheimer's diseased. Parkinson's disease
Answer:
Huntington's disease. (Ans. A)
Explanation:
Huntington's disease: It is known as the inherited disorder (degenerative) which cause the breakdown of the central nervous system.
Huntington's disease mainly causes functional abilities, and result in movements (such as slow eye movement, muscle problem like dystonia and rigidity), psychiatric (such as insomnia, feeling of sadness and loss of energy), and cognitive disorder (such as lack of action, and flexibility, slowness on finding words, etc.)
which best describes food when it reaches the stomach
Answer:
The polysaccharides have been broken down.
Explanation:
The polysaccharides have been broken down in to monosaccharides by the process of hydrolysis to make them small particles which can be easily absorbed by the body .
Answer:
It can be described as work efficiency
Explanation:
Food is the fuel and nutrients provide the body's cells with energy and that is required to function. But, for that, food must be digested, breaking down into smaller pieces so that they can be absorbed and taken advantage of.
The digestive system works efficiently and the stomach muscles agitate food and mix with digestive juices that have acids and enzymes, which achieves fragmentation into smaller, digestible pieces. Food leaves the stomach when it has been transformed into a thick liquid known as chyme. When the chyme is ready, it passes into the small intestine, where digestion continues so that the body absorbs nutrients, which will then go to the blood.
which of these is NOT true of cells?a. they are much like empty rooms.b. they were first discovered in the 1600sc. they can be found in pond waterd. they contain a huge array of working parts
Answer:
The answer is a. they are much like empty rooms.
Explanation:
Cells are pretty much the opposite of empty rooms. There are many organelles and processes happening in them, so there's no space for empty rooms. Even when there are spaces, which anyway would be full of liquid, these spaces have a purpose.
Some mice have a range of fur color that goes from white to dark brown. If the white mice and the dark brown mice are selected for while the intermediate colors become less frequent, this is an example of
A. directional selection
B. disruptive selection
C. none of the above
D. stabilizing selection
Answer:
The correct answer is B. disruptive selection.
Explanation:
Disruptive selection, in this case, would drive the population to go to a white group and a dark brown group. This meaning that the population starts to divide ending up with two different populations.
The nonmutant allele of the BRCA1 gene helps to suppress tumor formation in women who are heterozygous for the mutation. Women heterozygous for BRCA1 nevertheless have a 50% to 70% chance of developing breast cancer before age 70, and the usual reason is that the nonmutant allele is lost or inactivated in a lineage of cells. One possible mechanism for such "loss of heterozygosity" is:
A. germ cells in the affected individual develop a mutation in the nonmutant allele of BRCAL.
B. a somatic mutation in a breast cell inactivates the nonmutant BRCA1 allele.
C. a silent mutation occurs in the nonmutant BRCA1 allele.
Answer:
Option B
Explanation:
A silent mutation has no effect on the gene activity and function hence option C is incorrect. Germ cells would affect the gametes produced, not the body's proteins hence the answer would be B.
If a cross between two strains produces 130 parental ditype, 10 non parental ditype and 100 tetratype asci in the progeny, waht is the genetic map distance between the two loci (without correction for undetected double crossovers)?
Answer:
A genetic map is a type of chromosomal map that shows the relative location of genes and other important characteristics. The map is based on the concept of linkage, which means how close two genes are on the chromosome, the mayor will be the probability that they are inherited together. Following the inheritance patterns, the relative location of the genes throughout the entire chromosome can be established.
Illustration
[A genetic map] is a map that shows the relative location of two genetic traits. And the way to determine this is to use the descendants of an organism and keep track of how many times two genetic traits specify here together, for example, hair color and eye color. The higher the percentage of the descendants that have both characteristics at the same time, the closer to the chromosome the genes responsible for the characteristic characteristics.
When a male donkey is bred with a female horse, the offspring produced is a mule, which is healthy but sterile. Karyotyping experiments have revealed that horses and donkeys have different numbers of chromosomes, 64 for horses and 62 for donkeys. The mule, therefore, has 63 chromosomes. Knowing this, what is the best explanation for the inability of mules to produce offspring?
Answer:
In an organism with even number of chromosomes, the chromosomes become half in number during gamete formation . For example: A horse has 64 chromosomes. Its gametes will have 32 chromosomes. The gamete formation process in mules will fail because of its odd number of chromosomes.
63 chromosomes would not be able to divide perfectly for gamete formation. This will happen because proper pairing of homologous chromosomes will not occur during meiosis I. Synapsis is the pairing of homologous chromosomes before they segregate and chromosomal crossover also occurs during this stage. In mules, some gametes will be formed with missing chromosomes and some will have extra chromosomes because synapsis formation will be abnormal. Hence, mules are not able to produce viable gametes and are sterile.