A cross bridge in biological terms refers to the connection formed between actin and myosin during muscle contraction. Once the muscle fiber sarcolemma is excited, it leads to the myosin heads linking with actin, causing muscle contraction. This process is known as the cross bridge cycle.
Explanation:A cross bridge refers to the connection formed between the myosin heads of the thick muscle fibers and actin sites of the thin muscle fibers during the process of muscle contraction. This process is called the cross bridge cycle.
When the sarcolemma, the cell membrane of a muscle fiber, is stimulated or excited, it triggers a chain reaction resulting in the myosin heads 'reaching out' and forming a link or 'bridge' with the actin. This pulling action of the myosin heads shortens the muscle fiber, resulting in muscle contraction. Following this, the myosin heads release, the fiber relaxes and the cross bridges are 'uncoupled' until the next excitation event.
Learn more about cross bridge here:https://brainly.com/question/34609534
#SPJ12
The excitement of the sarcolemma triggers a crucial step in muscle contraction known as the cross-bridge cycle.
A cross bridge is fundamentally the transient connection that occurs between the myosin heads, which are located on the muscle's thick filaments, and the binding sites on actin, which makes up the muscle's thin filaments. The hydrolysis of ATP powers this interaction, which modifies the configuration of the myosin heads. The actin filaments slide over the myosin filaments as the cycle continues, shortening the sarcomere and leading to muscular contraction. The cross bridge goes through several stages during the cycle, including attachment, power stroke, and detachment. The intricate cross-bridge cycle demonstrates how muscle function is supported by a carefully choreographed molecular dance.
To know more about sarcolemma, here
brainly.com/question/31118956
#SPJ12
Which of the following is not a function of astrocytes? A. provide the defense for the CNS B. guide the migration of young neurons, synapse formation, and helping to determine capillary permeability C. support and brace neurons D. anchor neurons to blood vessels E. control the chemical environment around neurons
Answer:
A. provide the defense for the CNS
Explanation:
Astrocytes are star-shaped cells (glial cells) that are present in the brain and also in spinal cord.
Astrocytes perform number of the functions there, including; guidance to axons, synapse formation, supporting and bracing to the neurons, control of chemical environment around the neuron and control the blood brain barrier too.
Astrocytes provide various supports to neurons in the CNS but providing the defense for the CNS is primarily the function of microglial cells, not astrocytes.
Explanation:The primary role of astrocytes, a type of glial cell in the central nervous system (CNS), includes: maintaining the concentration of chemicals in the extracellular space, providing nutrients and structural support to neurons, and contributing to the blood-brain barrier. Specifically, astrocytes support neurons by anchoring them to blood vessels and controlling the chemical environment around them. They also guide the migration of young neurons and play a role in synapse formation. However, providing the defense for the CNS is not a function directly carried out by astrocytes. This function is principally performed by another type of glial cell known as microglial cells, which act as the main form of active immune defense in the CNS.
Learn more about Astrocytes Functions here:https://brainly.com/question/34188968
#SPJ11
put each tile to the correct location.
Categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both.
1) scientific theories 2) both 3) scientific hypothesis
A). a tentative statement used to guide scientific investigations
B). makes predictions about future events
C). can be tested many independent researches
D). based on observations of natural phenomena
E) . a well-established highly reliable explanation
Answer:
A) A tentative statement used to guide a scientific investigation is called scientific hypothesis.
As hypothesis is a proposed details of a phenomena, it can guide us in one way or another to carry out the scientific investigation.
B) Makes prediction about future events is scientific hypothesis.
Scientific hypothesis bases on the observation made predicts about future events, which could be either true or false.
C) Can be tested many independent researches is a scientific theory.
A scientific theory is developed when it has been passed through many researches and had gained acceptance too.
D) Both Scientific theory and hypothesis are based on the observations of the natural phenomena.
Firstly, an observation is made based on natural phenomena, which leads to questions, then research or study is carried out to answer these questions leading to the formation of a hypothesis which upon successful testing forms a theory.
E) Scientific theory is a well-established highly reliable explanation.
It a highly sustained explanation based on facts of nature, that are confirmed via a lot of experiments.
A scientific hypothesis is a tentative explanation used in scientific investigations, while a scientific theory is a well-established explanation backed by substantial evidence. Both can make predictions and be tested by independent researchers.
When categorizing the terms, it's critical to understand the distinction between a scientific theory and a scientific hypothesis.
A) A tentative statement used to guide scientific investigations would be a scientific hypothesis, which is typically a testable idea generated to explain observations in the natural universe.B) Making predictions about future events can be attributed to both a scientific theory and a hypothesis, as both can predict outcomes based on established evidence or a suggested solution.C) Can be tested by many independent researchers applies to both as well, as repeatability and verifiability are central to scientific principles.D) Based on observations of natural phenomena is also true for both, since scientific investigations start with observations that theories and hypotheses aim to explain.E) A well-established, highly reliable explanation is typical of a scientific theory, which represents a high level of scientific understanding and is supported by a significant body of evidence.In summary, for the tiles provided:
A) would be categorized under '3) scientific hypothesis'B) and C) would be categorized under '2) both'D) would be categorized under '2) both'E) would be categorized under '1) scientific theories'Explain what happens when a person exhales. What forces air out of the lungs? ResetHelp When you exhale, you reverse the process of inhalation. The chest cavity muscles relax, which decreases the lung volume, increasing the pressure within the lungs and forcing the air tense up the lungs.
Compare and contrast epidural and subdural hemorrhages.
Answer:
Epidural hemorrhages:
Epidural hemorrhage causes the laceration of middle meningeal artery. Temporal bone is mainly associated in this type of hemorrhage. Individual may suffer from loss of consciousness. Neurosurgery is important to treat the epidural hemorrhages.
Subdural hemorrhage:
Subdural hemorrhage causes the rupture of bridging veins. Dura matter of brain is mainly associated in this type of hemorrhage. Individual may suffer from minor head trauma. Neurosurgery is important to treat the epidural hemorrhages as well.
True or False: A person may be considered overweight but not obese.
Answer:
The answer to the question: A person may be considered overweight but not obese, is, true.
Explanation:
The diagnosis of obesity, vs overweight depends entirely on the BMI, the body mass index. This measure depends on the relation between a person´s weight, height and age, and it establishes the amount of body fat the person has. If the ratio found is between 25 and 29.9, in the BMI, then the person is considered overweight, but not obese. However, if the person´s BMI is 30, or above, then the person is declared obese. This is why the answer is true.
This portion of the vestibular apparatus is responsible for dynamic equilibrium.
Select one:
a. semicircular canals
b. sensory cells
c. vestibule
d. otoliths
Answer:
Semicircular canals
Explanation:
Ear is one of the important sense organ responsible for hearing and equilibrium. Human ear is divided into three parts: outer ear, middle ear and inner ear.
Inner ear is mainly responsible for the equilibrium of the body. Vestibular apparatus together with semicircular canals is responsible for the dynamic equilibrium of the body. Dynamic equilibrium involves head rotation and vertical movements of the body.
Thus, the correct answer is option (a).
The correct sequence of sound waves in the ear is ________.
Select one:
a. stapes > eardrum > malleus > oval window
b. auditory tube > incus > malleus > stapes > eardrum
c. eardrum > stapes > incus > malleus > inner ear
d. malleus > incus > stapes > oval window
The correct sequence of sound waves in the ear is 'malleus > incus > stapes > oval window'. This sequence represents the path of sound through the middle ear, from the eardrum, through three tiny bones, to the inner ear.
Explanation:The correct sequence of sound waves in the ear corresponds to option d. malleus > incus > stapes > oval window. This sequence represents how sound travels through the middle ear. Initially, sound waves strike the eardrum causing it to vibrate. These vibrations are amplified and transferred by three tiny bones in the middle ear: the malleus (hammer), incus (anvil), and stapes (stirrup), in that order. The stapes then pushes on the oval window, transmitting the sound waves into the inner ear.
Learn more about sound waves sequence in the ear here:https://brainly.com/question/7547770
#SPJ3
The correct order of sound waves traveling through the ear is eardrum, malleus, incus, stapes, and then the oval window. This chain of ossicles amplifies the sound vibrations from the eardrum to the inner ear.
The correct sequence of sound waves in the ear is eardrum > malleus > incus > stapes > oval window. This process reflects how sound waves travel through the ear to be converted into a form the brain can understand. When sound waves enter the ear, they first strike the tympanic membrane, or eardrum, causing it to vibrate. These vibrations are then transmitted through the three ossicles of the middle ear. The malleus (hammer) is connected to the eardrum and begins this chain by vibrating the incus (anvil), which then vibrates the stapes (stirrup). The stapes is in contact with the oval window, the membrane that marks the entrance to the inner ear, and it sends vibrations into the cochlea, a fluid-filled structure that ultimately transduces them into neural signals.
32. Which of the following is NOT a major component of plant chloroplasts?
a. Stroma
b. Thylakoid
c. Granum
d. Cytosol
Answer: d. Cytosol
Explanation:
The highly organized system of membranes in chloroplasts is essential to the functioning of photosynthesis. These three components are part of plant chloroplasts:
Thylakoids - Internal membranes of chloroplasts that have sac-like organizations.
Grana - When those thylakoids are combined in piles, stacked on top of one another we call them Grana.
Stroma - The semiliquid membrane system enclosing the thylakoid that houses enzymes required to accumulate carbon molecules.
While all those components are part of plant chloroplasts, the cytosol is part of the largest of the internal membranes of eukaryotic cells, called endoplasmic reticulum (ER). More specific it is the region exterior of the ER, while the inner region is called the cisternal space.
The component that is not a major part of plant chloroplasts is cytosol. The stroma, thylakoid, and granum are all integral parts of chloroplasts, with the stroma housing the Calvin cycle, which are the light-independent reactions of photosynthesis.
The component that is NOT a major part of plant chloroplasts among the options given is cytosol (option d). The stroma is the fluid-filled space surrounding the thylakoids within the chloroplasts. A thylakoid is a membrane-bound compartment inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Granum (plural: grana) refers to a stack of thylakoids within the chloroplasts. The cytosol, however, is the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended, but it is not part of the chloroplast.
The light-independent reactions of photosynthesis, also known as the Calvin cycle, take place in the chloroplast stroma. While the light-dependent reactions occur in the thylakoid membranes, the thylakoid lumen, or the granum, all of which are related to the process of photosynthesis, the cytosol is involved in many metabolic pathways but is not where the Calvin cycle occurs.
Which of the following minerals helps maintains osmotic pressure, regulates pH, and required for the conduction of nervous impulses along axons?
a. Copper
b. Chlorine
c. Phosphorus
d. Sodium
Answer: d. Sodium
Explanation:
Sodium (Na), has atomic number 11, it makes up 2.8% of Earth's crust by weight and 0.2% of the human body by weight. It is the principal positive ion outside cells, has an essential role in maintaining water balance inside the cells, important in nerve function, and blood pressure regulation when combined with potassium.
Which of the following is not a problem in ground water pollution? A. gasoline from underground tanks seeps into rock and soil B. sewage pollutes water in wells C. industrial wastes contaminate water in wells D. plant nutrients cause algal blooms
Answer:
D. plant nutrients cause algal blooms
Explanation:
Plant nutrients causing algal blooms does not lead to ground water pollution.
Ground water is water in the subsurface of the earth which occupies pore spaces and fractures within the soils and rocks.
Ground water pollution is the contamination of ground water by pollutants. When gasoline from underground seeps and transmits using pore spaces within the rock, they can get into an aquifer thereby contaminating the water there. Also, when sewage disposal units are located up slope, a pressure gradient allows sewage to move within the pore spaces thereby contaminating ground water. Industrial wastes can also contaminate wells when they are not properly discharged.
Algal bloom as a result of plant nutrients leads to eutrophication.
Choose the false statement concerning the effects of epinephrine-cAMP signaling on various cell types.
stronger smooth muscle contraction.
liver cell glycogen breakdown to glucose.
increase in intestinal epithelial cell fluid secretion.
stronger heart muscle contraction.
inhibition of platelet activation during blood clotting.
Answer:
Inhibition of platelet activation during blood clotting.
Explanation:
Epinephrine serves as one of the weak agonists for platelets. Binding of epinephrine to alpha-adrenergic receptors serves to stimulate the activation of platelets. It does not inhibit the platelet activation during clot formation. Being a weak agonist, epinephrine can stimulate the platelet activation directly but depends on strong agonists such as thrombin to initiate the process.
How does the epithelium of the colon differ from that of the small intestine?
Answer:
Colon epithelium:
The colon of large intestine is lined by the simple columnar epithelium. The epithelium covers the brush border and also lines the goblet cells of the colon.
Small intestine epithelium:
The epithelium of small intestine is lined by the mucosa epithelium tissue as well as the simple columnar epithelium. These tissue secrete mucus in the small intestine.
1. You are studying a trait in corn that you believe exhibits Mendelian inheritance. You count phenotypes and find that there are 375 of one phenotype and 125 of the other phenotype. When you perform a chi-square test, the chi-square value is zero. Your conclusion based on this test is
this trait is inherited in a Mendelilan fashion
none of the answers is correct
this trait exhibits codominance
this trait is not inherited in a Mendelian fashion
this is a dihybrid cross
Answer:
This trait is inherited in a Mendelian fashion.
Explanation:
Chi-square test is used to test the relationship b/w variables, on performing the chi-square test on traits of corn, value that we obtained was zero, it means that there is no relationship b/w two traits. So, the trait has been inherited independently in Mendelian fashion.
Answer:
this trait is inherited in a Mendelian fashion
Explanation:
The chi-square test aims to verify whether the observed absolute frequency of a variable is significantly different from the expected absolute frequency distribution. Applies when one wants to study the dependency between two variables, through a double entry table or also known as a contingency table.
When chi square is calculated, the values of a table with constant numbers (called tabulated X) are compared with the result found in the chi square calculation. If the chi-squared value is zero, then there are no significant differences between the hypotheses. In the case of the above question, this would mean that the characteristic, studied in the above question, is inherited from Mendelian ways.
Helper T (TH) cells recognize antigens when they are bound to a(n)
A. hapten.
B. immunoglobulin.
C. natural killer cell.
D. major histocompatibility complex (MHC) protein.
Answer:
d
Explanation:
Helper T cell and inflammatory T cell TCRs recognise epitopes displayed by MHC class II molecules on the surface of antigen-presenting immune cells, including: macrophages that engulf foreign particles such as bacteria; dendritic cells that present antigen to T cells; and B cells that produce antibodies.
Final answer:
Helper T (TH) cells recognize antigens when bound to a major histocompatibility complex (MHC) protein. T cell receptors (TCRs) on T cells bind to the foreign protein fragments presented on MHC proteins by antigen-presenting cells (APCs).
Explanation:
Helper T (TH) cells recognize antigens when bound to a major histocompatibility complex (MHC) protein. T cells have antigen receptors on their surface called T cell receptors (TCRs), which bind to the foreign protein fragments (peptides) presented on MHC proteins by antigen-presenting cells (APCs) such as macrophages or dendritic cells. The TCRs recognize and bind simultaneously to the foreign protein fragment and the MHC protein on the APC surface.
Which of the following statements is FALSE? Individuals produced by asexual reproduction are clones of the parent. Mitosis is the basis of asexual reproduction in many eukaryotes. Mitosis occurs in somatic cells whereas meiosis occurs in germ cells. Individuals produced by asexual reproduction are haploid because fertilization does not occur to restore the diploid chromosome number. None of the answer options is false
Answer:
Individuals produced by asexual reproduction are haploid because fertilization does not occur to restore the diploid chromosome number.
Explanation:
In humans, somatic cells are diploid cells, containing two sets of chromosomes (2n). These cells can be found in the skin, blood and muscle cells. The number of chromosomes (n) differs in different organisms, and in humans, the complete set (2n) comprises 46 chromosomes.
Haploid cells are found in gametes or germ cells, and contain only one set of chromosomes (n). An example of haploid cells is the cells found in sperm and eggs.
With this, we can conclude that the individuals produced by asexual reproduction are not haploid because fertilization occurs to restore the number of diploid chromosomes.
The false statement is that individuals produced by asexual reproduction are haploid due to the absence of fertilization; in reality, they are clones of the parent and maintain the same ploidy level, typically diploid, through mitosis.
Explanation:The statement that is FALSE among the options provided is: Individuals produced by asexual reproduction are haploid because fertilization does not occur to restore the diploid chromosome number. This is incorrect because individuals produced by asexual reproduction are actually clones of the parent and are typically diploid if the parent is diploid. This mode of reproduction does not involve the reduction of chromosome number that occurs during meiosis. Instead, it involves mitosis, a process where a eukaryotic cell divides to produce two genetically identical daughter cells, each with the same number of chromosomes as the parent cell.
In asexual reproduction, a single parent passes a complete copy of its genetic information to its offspring, thereby producing clones. This is different from sexual reproduction, where meiosis reduces the chromosome number by half to produce haploid gametes, and fertilization restores the diploid number when two gametes from different parents fuse.
Learn more about Asexual Reproduction here:https://brainly.com/question/4100787
#SPJ6
Thermal decomposition of rail car load of limestone to lime and carbon dioxide requires 7.92 x 106 kJ of heat. Convert this energy to calories. Once you have the value, determine its log (base 10) and enter this in decimal format with three decimal places. Do not include units.
Answer:
[tex]9.276[/tex]
Explanation:
As we know that one kilo joules is equal to [tex]239.006[/tex] gram calories
Given ,
Energy required by thermal decomposition of rail car load of limestone to lime and carbon dioxide is equal to
[tex]7.92 * 10^6[/tex] Kilo joules
This kilo joules of energy is converted into calories and is equal to
[tex]7.92 * 10^6 * 239.006\\= 1.892*10^9[/tex]
On taking the log of this value, we get -
log ([tex]1.892 * 10^9[/tex]) [tex]= 9.276[/tex]
Hence, the answer is [tex]9.276[/tex]
To convert the given energy from kJ to calories use the conversion factor 1 kJ = 239 cal. The log (base 10) of the converted energy is 9.28.
The thermal decomposition of limestone to lime and carbon dioxide requires 7.92 x 10^6 kJ of heat. To convert this energy to calories, we can use the conversion factor: 1 kJ = 239 calories.
Therefore, 7.92 x 10^6 kJ = 7.92 x 10^6 kJ x 239 cal/1 kJ = 1.89 x 10^9 cal.
The log (base 10) of 1.89 x 10^9 is 9.28 (to three decimal places).
Tina and Russell Stovers want to start a family. However, Tina had her fallopian tubes tied and now is unable to get pregnant. The Stovers have opted for a procedure in which a woman's ova are removed from her ovaries, and a man's sperm are used to fertilize the ova in a laboratory. This method of fertilization is known as________.
Answer:
In Vitro fertilisation (IVF)
Explanation:
The technique being talked about in this case is known as “In Vitro Fertilization (IVF)”
In this technique, egg and sperm can be fertilized in external environment i.e outside female body. The fertilized ova is then placed in the uterus. The Follicle Stimulating Hormone (FSH) enhances the production of egg. Thus, FSH is given to women to produce more number of eggs which are then collected and fertilized with sperm under regulated temperature and environmental condition.
Tina and Russell Stovers have opted for in vitro fertilization (IVF) to overcome their difficulty in getting pregnant.
Explanation:The method of fertilization that Tina and Russell Stovers have opted for is called in vitro fertilization (IVF). In IVF, a woman's eggs are retrieved from her ovaries and fertilized with a man's sperm in a laboratory. The fertilized embryos are then transferred to the woman's uterus for implantation and development.
Learn more about in vitro fertilization (IVF) here:https://brainly.com/question/5504838
#SPJ12
Be sure to answer all parts. Imagine conducting the Meselson and Stahl experiment on DNA that is replicated by the dispersive mechanism. After 3 rounds of replication, what percentage of the DNA would contain exclusively 15N, exclusively 14N, or a mix of 14N and 15N?
Answer:
25% mixture of N15 and N14 and 75% of exclusively N14.
Explanation:
In the Meselson and Stahl experiment a double DNA chain formed by N15 is placed in a medium with only N14. Therefore, when replicated, the new chains will be synthesized with N14 (lighter). This can be corroborated by centrifuging the sample.
Before replication, a single band corresponding to the double helix of N15 DNA is observed.
After a single replication, only one band corresponding to DNA is observed with 1 strand N15 and 1 strand N14.
After the second replication, two bands will be observed. One for DNA of 1 strand N15 and 1 strand N14 and the other for DNA of 2 strands N14.
The same will happen for the third replication. At this point, the DNA present will consist of a 25% mixture of N15 and N14 and 75% of exclusively N14.
This experiment proves that DNA replication is semi-conservative.
Final answer:
After three rounds of replication, 25% of the DNA would contain exclusively 14N, while the remaining 75% would be a mix of 14N and 15N. No DNA would contain exclusively 15N.
Explanation:
The Meselson and Stahl experiment was conducted to determine how DNA replicates. They used E. coli bacteria and labeled the DNA with a heavy isotope of nitrogen (¹5N). After one round of cell division in 14N media, the DNA sedimented halfway between the 15N and 14N levels, indicating that it now contained fifty percent 14N. This result supports the semi-conservative replication model.
After three rounds of replication, the percentage of DNA containing exclusively 15N would be zero, as the initial heavy isotope of nitrogen would be diluted with each round of replication. The percentage of DNA containing exclusively 14N would be 25%. This is because the 14N DNA will replicate during each round, resulting in an increasing amount of 14N-only DNA with each cycle. The remaining 75% of the DNA would be a mix of 14N and 15N, as some of the original 15N DNA would still be present after three rounds of replication.
How does water get from the atmosphere into the groundwater system? a. Water from the ocean is sucked up into the groundwater system due to a pressure difference. b. Precipitation falls into rivers and then flows downriver into the groundwater system. c. Plants secrete water into the groundwater system in a process called evapotranspiration. d. Precipitation falls on the ground and infiltrates the ground surface to the groundwater system.
Answer:
d. Precipitation falls on the ground and infiltrates the ground surface to the groundwater system.
Explanation:
Water gets from the atmosphere into the groundwater system because precipitation falls on the ground and infiltrates the ground surface to the groundwater system.
d. Precipitation falls on the ground and infiltrates the ground surface to the groundwater system.
Can precipitation infiltrate into groundwater?Groundwater flows underground
Some of the precipitation that falls onto the land infiltrates into the ground to become groundwater. If the water meets the water table (below which the soil is saturated), it can move both vertically and horizontally.
What happens when precipitation falls to the ground?
Precipitation comes as rain, snow, sleet, ice pellets, dew, hail, and other types, but we will call it all "rain" from here on. When too much rain falls onto the ground to conveniently infiltrate the soil, part of it "runs off". Gravity pulls it directly downhill.
Learn more about groundwater here: https://brainly.com/question/9617
#SPJ2
What do "extension" and "flexion" mean?
Answer:
Extension:
Extension is the movement of body that increases the angle between two body parts. The elbow extension increases the angle between ulna and humerus . The knee extension increases the lower limb.
Flexion:
Flexion is the movement of body that decreases the angle between two body parts. The elbow flexion decreases the angle between humerus and ulna. The knee flexion causes the decrease an angle between tibia and femur.
Which of the following describes the nervous system integrative function? A. responds to stimuli by gland secretion or muscle contraction B. analyzes sensory information, stores information, makes decisions C. senses changes in the environment
Answer:
B. analyzes sensory information, stores information, makes decisions
Explanation:
The receptors sense the changes or stimuli. The sensory neurons of the nervous system deliver this sensory information to the processing center, that is, to the central nervous system. The central nervous system serves to store the information and analyze it to determine the best suitable response. The ability of the nervous system to the store and process of sensory information to make the effector organs to exhibit the best response represents its integrative function.
Answer:
B. analyzes sensory information, stores information, makes decisions.
Explanation:
The nervous system is the body’s main communication system; it gathers, synthesizes, and uses data from the environment. The most basic unit of the nervous system is the neuron, which serves as both a sensor and communicator of internal and external stimuli. The nervous system can be broken down into two major parts—the central nervous system and the peripheral nervous system. The central nervous system, the main data center of the body, includes the brain and spinal cord. The peripheral nervous system includes all of the neurons that sense and communicate data to the central nervous system. The peripheral nervous system can be further divided into the autonomic system, which regulates involuntary actions, and the somatic system, which controls voluntary actions.Learn more about nervous system, refer:
https://brainly.com/question/1023876.The cells responsible for the production of circulating immunoglobulins are ________ cells.
Answer: The cells responsible for the production of circulating immunoglobulins are Plasma cells (white blood cells).
Explanation: Immunoglobulins are the glycoprotein molecules.They produce immune response by recognizing and binding to the particular pathogen.
Plasma cells are found in bone marrow. B cells differentiate into plasma cells and produce immunoglobulins.
Final answer:
Plasma cells, differentiated from B cells, are responsible for the production of circulating immunoglobulins which are crucial for the body's defense against extracellular pathogens and toxins.
Explanation:
The cells responsible for the production of circulating immunoglobulins are plasma cells.
B cells, also known as B lymphocytes, develop within the bone marrow and are crucial in the body's adaptive immune system. Upon activation by an antigen, they differentiate into plasma cells, which are specialized for the production of antibodies, or immunoglobulins. These antibodies are glycoproteins involved in the body's defense against extracellular pathogens and toxins. There are five main classes of immunoglobulins: IgG, IgM, IgA, IgD, and IgE, each with its specific functions within the immune system.
Once stimulated by an antigen-presenting cell, helper T cells release cytokines that prompt B cells to proliferate and form either plasma cells, which produce antibodies, or memory B cells, which respond to subsequent encounters with the same antigen. This process is a part of humoral immunity, which is distinct from cell-mediated immunity involving T cells that target intracellular pathogens.
Direct stimulation of the insulin-secreting cells of the pancreas by the autonomic nervous system is an example of _____ control.
a,negative feedback
b.positive feedback
c.neural
d.substrate-level dependent
Answer:
c. neural
Explanation:
Direct stimulation of the insulin-secreting cells of the pancreas by the autonomic nervous system is an example of neural control.
Which of the following statements is false? The hormone progesterone causes the endometrium to become thicker. After the ovarian follicle ruptures, it fills with yellow fat and is called the corpus luteum. FSH stimulates the follicles to produce mature ova. A woman creates new immature ova in the ovary each time she has a menstrual cycle.
Answer:
A woman creates new immature ova in the ovary each time she has a menstrual cycle.
Explanation:
During the menstrual cycle, hormones present in the body make the immature eggs 'mature' ones, in the ovary. About in half of the cycle, hormones make the release of the mature egg from the ovary and travels towards uterus. It can remain there for 24 hours and if not fertilized the it breaks down and released out.
Answer:
The false statement is: A woman creates new immature ova in the ovary each time she has a menstrual cycle
Explanation:
This is false because the ovules cannot leave the ovary in the immature form since the ova could not fuse with the sperm in the fallopian tubes, the ovum must always leave the ovary in its mature phase. In the menstrual cycle, the ovule also comes out in a mature way and tries to merge with sperm and implant itself in the endometrium, but if this fertilization is not achieved, the mature ovum will leave with the lining of the endometrium and the menstrual flow is created.
21. Which step in cellular respiration occurs outside of the inner membrane space of the cell mitochondria? a. Krebs Cycle c. Transition Reaction b. Citric Acid Cycle d. Phosphorylation Reaction
Answer: c. Transition Reaction
Explanation:
During the transition reaction, Acetyl-CoA is formed and connects the first stage of glycolysis with the Krebs Cycle (Citric Acid Cycle). In the presence of oxygen, pyruvate enters the mitochondria and is oxidized to form a compound of 2 carbon, acetate, with energy and CO2 release. During this process, the acetate binds to a coenzyme(coenzyme A (CoA)) - forming the acetyl-coenzyme A.
The 3 steps:
1. pyruvate is oxidized and forms acetate with liberation of CO2;
2. the energy released in the oxidation of pyruvate is stored in the reduction reaction of NAD+ to NADH + H+
3. The acetate molecule combines with coenzyme A to form acetyl-coenzyme A.
The Citric Acid Cycle or Krebs Cycle occurs outside of the inner membrane space of the cell mitochondria.
Explanation:The step in cellular respiration that occurs outside of the inner membrane space of the cell mitochondria is the Citric Acid Cycle or Krebs Cycle. This cycle takes place in the mitochondrial matrix and involves a series of redox and decarboxylation reactions. During the cycle, high-energy molecules including ATP, NADH, and FADH₂ are produced.
Learn more about Citric Acid Cycle here:https://brainly.com/question/30421074
#SPJ3
44. Which of the following choices is NOT a major component of vascular plant leaf anatomy?
a. Palisade mesophyll
b. Xylem channels
c. Respiration stomata
d. Elastic channels
Answer:
The correct answer is option d. "Elastic channels".
Explanation:
The vascular plants uses xylem and phloem cells that carry water and nutrients to all the parts of the plant, which are present in the leaves of the plant. Stomata is part of the vascular system of a plant, but it serves for gas exchange instead of water and nutrients exchange. Palisade mesophyll is a structural component that contains columnar cells with spaces between them, located in the leaves of vascular plants as well. A component that is not part of the vascular plant leaf anatomy are the elastic channels.
why was ice used during the extracting DNA
Answer: The Cold Water temperature helps increase the attachment of the DNA Explanation:
Using ice-cold ethanol and ice-cold water increases the yield of DNA. Low temperatures protect the DNA by slowing down the activity of enzymes that could break it apart. ... DNases in the cytoplasm would destroy the DNA of viruses entering the cell. Cold ethanol helps the DNA to precipitate more quickly
Which of the following is NOT true about the absorption of fats?
a. Fatty acids dissolve into the epithelial cell membrane.
b. The epithelial cells re-synthesize the fatty acids and coat them with protein forming chylomicrons.
c. The chylomicrons enter the blood in the villi capillaries.
d. The blood transports the chylomicrons to the muscles and adipose cells.
Answer:
The best choice from the answer options for the question: Which of the following is NOT true about absorption of fats, would be: C: The chylomicrons enter the blood in the villi capillaries.
Explanation:
Because of the characteristics of fatty acids, and fats in general, they are not able to either pass the intestinal enterocytes, and enter the bloodstream, as easily as glucose, or other molecules, can. Instead, they first must be passed into the enterocytes, the intenstines´ cells, by their combination with bile. Once inside the intestine, the enterocytes take up the fats and combines them with lipoproteins and cholesterol in order to create the chylomicrons. But before these chylomicrons can make their way to the blood, first they must be taken up by the lymphatic vessels present in the villus of the intestinal epithelium, not the blood capillaries. It will be the lymphatic system which will be reponsible for passing the fats to the bloodstream, who will then distribute them to the appropriate cells in the body as energy is required. Or they will be taken for storage by the liver.
The incorrect statement regarding the absorption of fats is c. Chylomicrons enter the lacteals, not the blood in the villi capillaries, and are later transported to the bloodstream.
Explanation:The answer to the question which of the following is NOT true about the absorption of fats? is c. The chylomicrons enter the blood in the villi capillaries. This statement is incorrect because chylomicrons do not directly enter the blood capillaries within the villi. Instead, chylomicrons exit epithelial cells and enter the lacteals, which are part of the lymphatic system. The chylomicrons travel through the lymphatic vessels and are eventually released into the bloodstream at the subclavian vein. Therefore, options a, b, and d are true statements about the absorption of fats, as the fatty acids do dissolve into the epithelial cell membrane, the epithelial cells re-synthesize them and coat them with protein to form chylomicrons, and the blood transports chylomicrons to the muscles and adipose cells.
Which neural term is a synonym for action potential?
Answer: We can express some synyms for action potential, such as, AP (action potential), nerve impulse, and conduction signal.
Explanation:
Nerve cells transmit information to each other to the others through electrical impulses called action potentials (PA), making the communication of neurons similar to a network of electronic circuits. Generally, action potentials are dependent on the activation of sodium channels (Na +), which open in response to variations in membrane potential and are therefore characterized as voltage-dependent.
The correct option is Option D (Nerve Impulse). An action potential, synonymous with a nerve impulse, is a brief electrical charge that travels along a neuron’s membrane. This process involves a rapid change in the membrane’s electrical potential. Depolarization is a key phase in action potential generation.
An action potential, also known as a nerve impulse, is a brief electrical charge that travels along the membrane of a neuron. This process involves a momentary change in the electrical potential of the neuron's membrane. During action potential generation, the cell membrane potential changes quickly from negative to positive due to the flow of sodium ions into the cell and potassium ions out of the cell, which is termed depolarization.The full question is available online. The question is :
Which neural term is a synonym for action potential?
a) Axoplasm
b) Axolemma
c) Synaptic knob
d) Nerve impulse
Why are some microscopic organisms, such as mites and worms, categorized as invertebrate parasites instead of being categorized as “true” microbes? Choose one: A. Invertebrate animals have complex organ systems not found in “true” microbes. B. “True” microbes are bacteria and viruses. C. Groups classified as “true” microbes do not contain macroscopic forms. D. Invertebrate parasites do not cause human diseases.
Answer:
A. invertebrate animals have complex organ systems not found in true microbes.
Explanation:
Mites and worms are considered as invertebrate parasites as they have complex organ systems like other invertebrates which are simpler in microbes. Invertebrates have complex organ system that is comprised of complex network of veins capillaries and nerves, while in microbes simpler form of such systems are present.
Invertebrate parasites such as helminths are categorized differently from 'true' microbes because they have complex organ systems and are multicellular, unlike bacteria and viruses, which are the primary constituents of the 'true' microbes category.
Explanation:Some microscopic organisms, such as mites and worms, are categorized as invertebrate parasites instead of being categorized as 'true' microbes because invertebrate animals have complex organ systems not found in 'true' microbes. 'True' microbes typically refer to bacteria and viruses, which do not contain complex organ systems. In contrast, invertebrate parasites, such as helminths, may have organ systems for reproduction, digestion, movement, and other functions that go beyond the cellular complexity of bacteria and viruses.
Parasitic helminths are included within the field of microbiology due to their microscopic eggs and larvae, but adult forms of some helminths are visible to the eye. As such, helminths are multicellular and are not technically microorganisms; however, they are studied by microbiologists due to the relevance of their microscopic stages in disease transmission and identification. On the other hand, viruses are acellular microorganisms and have a different biological structure, lacking the complex cell structures of eukaryotic organisms.