Answer:
The correct answer is ''loss of acetylcholine receptors in the end-plate membrane.''
Explanation:
Myasthenia gravis represents a human autoimmune disease. The neuromuscular junction abnormalities that occur in this disease are due to antibody-mediated processes. A reduction in the number of functional acetylcholine receptors on the postsynaptic membrane was established to contribute to the physiological abnormalities of myasthenia gravis. The reduction in receptors is due to immunological alterations directed against the acetylcholine receptor. Normally, when acetylcholine binds to its receptor, it opens allowing the rapid entry of cations, especially sodium. With this, the depolarization of the postsynaptic region of the muscle fiber occurs. Although acetylcholine is normally released in myasthenia gravis, it is not capable of causing an action potential in the muscle sufficient to initiate or weaken contraction. In patients with myasthenia gravis, failure to activate muscles is responsible for myasthenic fatigue. Most patients have elevated serum titers of antireceptor antibodies, which in turn accelerate receptor degradation.
A common genetic mutation that lowers levels of the enzyme cathepsin C severely reduces a person’s ability to ward off periodontitis, or gum disease. The enzyme triggers immunological reactions that destroy diseased cells and eliminate infections
in the mouth. But researchers are developing ways to restore the enzyme to normal levels. Once that happens, we will be able to eliminate periodontitis.
Which one of the following is an assumption on which the argument depends?
(A) Restoring cathepsin C to normal levels is the only way to eliminate periodontitis.
(B) Genetic mutation is the only cause of lowered levels of cathepsin C.
(C) Researchers will soon succeed in finding means of restoring cathepsin C to normal levels.
(D) Persons who do not have the genetic mutation that lowers levels of cathepsin C do not get gum disease.
(E) A person whose cathepsin C level has been restored to normal will not suffer from periodontitis.
Answer:
(E) A person whose cathepsin C level has been restored to normal will not suffer from periodontitis.
Explanation:
Considering the fact that there may be some other causes of periodontitis aside from the lowered levels of the enzyme.
Therefore, should there be some other causes of periodontitis, hence, it can be concluded the process of restoring the enzyme to normal levels might not be sufficient for eliminating periodontitis.
Hence, the author's argument is solely based on this assumption, and option. Hence, option (E) is the correct answer.
The purpose of Mendel's experiments with dihybrid crosses was to determine
whether:
A. an F2 generation could be produced from the Fi offspring.
B. one of two traits could be transformed by DNA.
O c. one trait would affect how another is inherited.
D. traits are controlled by more than one gene.
Answer:
C. one trait would affect how another is inherited
Explanation:
What type of unconformity did Hutton see at Siccar Point and how was this uniformity formed?
Answer:
Hutton's Unconformity
At Siccar Point, during the lower Silurian Llandovery epoch around 435 million years ago, thin beds of fine-grained mudstone were laid down gradually deep in the Iapetus Ocean, alternating with thicker layers of hard greywacke formed when torrents swept unsorted sandstone down the continental slope. Siccar Point is a rocky promontory in the county of Berwickshire on the east coast of Scotland. It is famous in the history of geology for Hutton's Unconformity found in 1788, which James Hutton regarded as conclusive proof of his uniformitarian theory of geological development.
If something is tucked in, this means it is
covered with shells
folded up and small
immersed in water
in a snug or hidden place
Answer:
in a snug or hidden place
What element is commonly used to date archaeological or geological materials?
Select one:
a. Phosphorus
b. Nitrogen
c. Hydrogen
d. Carbon
Answer:
D. Carbon
Explanation:
Carbon is the element that is commonly used to date fossils and ancient materials.
This is called carbon dating, where the concentrations of different carbon isotopes are used to determine the age of ancient materials.
Carbon dating has been used for almost 70 years and is still commonly used to date fossils.
So, the correct answer is D. Carbon
If there is a high concentration of carbon dioxide in the blood stream, it will diffuse into the _______
A. Hemoglobin
B. Alveolus
C. Capillary
D. Protein Channel
If there is a high concentration of carbon dioxide in the bloodstream, it will diffuse into the Capillary (Option C).
What are pulmonary capillaries?Pulmonary capillaries are small blood vessels that are able to perform gas exchange.
The process of gas exchange in the respiratory system is fundamental for carrying out cellular respiration by obtaining oxygen from the air.
In conclusion, the high concentration of CO2 in the bloodstream diffuses into the capillaries (Option C).
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Why the leading and lagging strand of DNA synthesize through different mechanism?What factor determine these differences
Answer:
ناسحتصس حساب سكسوسشت كمسنصو م٩سس
What energy using-process helps to cool the body
Answer:
Convection
Explanation:
convection is the process of losing heat through the movement of air or water molecules
If you were running an experiment to determine the color of light at which beans grew best, what would be the variable?
Group of answer choices
the number of beans plants in the experiment
the amount of water you give the beans
the color of the light under which each bean is grown
the height to which you let the sprouts grow
Answer:
The number of beans in the experiment
Explanation:
I hope it helps choose me the brainer
which best describes a bacterium
Answer:
Bacteria
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Wikipedia
Explanation:
a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease.
Two populations of frog species are separated by a group of mountains. A tunnel is built through the mountains, through which some of the frogs are able to safely navigate, and attempt mating with frogs on the other side of the tunnel. However, their heroic feat is for nothing, because their offspring all produce sterile young. This scenario is an example of
Answer:
Post reproductive isolation → Hybrid sterility
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
Postzygotic mechanisms or barriers include
Hybrid inviability, Hybrid sterility, Hybrid decreased viability or fertility, Cytoplasmic interactions.In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.
Determine if the following statement is true or false and why: All organisms make their own food, but plants are the only kind to do so using sunlight. A. False, not all organisms can make their own food, only plants and some bacteria. B. False, all organisms can use sunlight to make food. C. False, plants cannot make their own food. D. True
Answer:
A. False, not all organisms can make their own food, only plants and some bacteria.
Explanation:
It's right
The description of the statement whether it is true or false is described below:
All organisms make their own food, but plants are the only kind to do so using sunlight. (False).Not all organisms can make their own food, only plants, and some bacteria. (True). All organisms can use sunlight to make food. (False). Plants cannot make their own food. (False). How do plants prepare their own food?Plants prepare their own food with the process of photosynthesis which utilizes carbon dioxide and water and synthesizes glucose in the presence of sunlight.
Plants, some photosynthetic algae, and some bacteria prepare their own food with the help of sunlight. They have a photosystem that captures the energy of sunlight in the food production mechanism.
Therefore, it is well described above.
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Whats a hypothesis for “Which bait works better for a homemade fly trap?”
Answer:
If I use the correct bait, then I will have a successful homemade fly trap.
Explanation:
A hypothesis is always an "if, then" statement
The teacher was unaware of the difference between suspension feeding and predation. The teacher thought that providing live copepods (2 mm long) and feeder fish (2 cm long) would satisfy the dietary needs of all of the organisms. Consequently, which two organisms would have been among the first to starve to death (assuming they lack photosynthetic endosymbionts)
Answer:
The correct answer is - Biwalves and sponges.
Explanation:
Suspension feeders are the organisms that depend on, for the dietary needs or nutriton, materials suspended in the water. The materials that are suspended are living organisms such as phytoplankton and zooplankton.
Biwalves and sponges are suspended or filter feeders and not predators like other organisms so providing copepods will not complete their food requirement and they will starve to death.
The correct answer is - Biwalves and sponges.
Where do convection currents occur atmophere
Answer:
Convection takes place in the atmosphere, in the oceans, and in Earth's molten subcrustal asthenosphere.
Explanation:
3. What is one thing that can be done to help improve areas that produce a lot of runoff?
Answer: hi, im here to help :3
so, you can either use plants, use pesticides and fertilizers less often or the one thing i know is consider a rain barrel.
Which correctly describes Earth's population over the centuries?
O A. It has risen steadily.
B. It has remained steady overall.
C. It has risen at an increasing rate.
O D. It has declined in some places due to migration.
SUBM
Earth's population over the centuries has risen at an increasing rate. So, the correct option is C.
How the population of Earth is increasing?This sharp increase in population has been primarily caused by an increase in the proportion of individuals reaching breeding age, the gradual extension of human life expectancy, growing urbanization, and quickening migration. This expansion has been accompanied by significant changes in the fertility rate.
One of the key reasons for India's population expansion is a drop in death rates brought on by better medical services and a steady birth rate. The widespread illiteracy in India makes people believe that "children are god's blessings," which makes them opposed to the idea of "family planning." Earth's population over the centuries has risen at an increasing rate.
Therefore, the correct option is C.
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To test how fertilizer affects tomato plants, a farmer divided a field of young
tomato plants into 10 plots of equal size. The farmer then put fertilizer on half
of the plots and no fertilizer on the other half of the plots. What is the control
group in this experiment?
Answer:
The plots with no fertilizer
Explanation:
In an experiment, the control group is used as a comparison for the experimental group (the group being actively changed and observed).
So, in this experiment, the control group is the plots with no fertilizer.
This acts as a good control group because it provides a normal standard to show the effect of fertilizer on the tomato plants.
So, the control group in this experiment are the plots with no fertilizer.
Hyperscience is...
1. Genetically modifying plants.
2. quickly producing new plant varieties.
3. growing plants using new technology.
4. responding to the horticulture market.
Answer:
2
Explanation:
A pesticide tolerance refers to the a. amount of a pesticide that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace. b. ability of the liver to detoxify a pesticide c. toxicity of the pesticide in the laboratory d. number of pests that are killed by a selected dose of the pesticide
Answer:
a. amount of a pesticide that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.
Explanation:
Pesticides are chemical substances used to get rid of or kill pests that attack crops on farmlands. These pesticides, although help the farmer to get rid of his pest problem and likely have an increase in yield, are dangerous to human and animal health if consumed.
As set up by the Environmental Protection Agency (EPA), pesticide tolerance is the amount or quantity of pesticide chemical that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.
list and explain the advantages of 5 farming systems
ruth is presenting the feedback model to her class help her complete the statements
Answer:
Feedback models are tools that provides specific, concise, and clear feedback for a particular thing.
Explanation:
Feedback models are tools that provides specific, concise, and clear feedback for the organization so that an organization can make useful changes which is necessary for the organization growth and development. There is high need of this feedback model which helps us to know about the specific areas where one needs to improve performances in order to work more effectively.
Which concept is illustrated in the flowchart below?
Overproduction arrow pointing Struggle for survival arrow pointing Survival of the fittest arrow pointing Changes in traits of species
Dynamic equilibrium
Genetic manipulation
Material cycles
Natural selection
Answer:
Natrual selection
Explanation:
your welcome girlies <333
The concept illustrated in the flowchart is Natural selection. The correct option is 4.
What is natural selection?Natural selection is the process by which species evolve over time as the prevalence of certain traits increases or decreases in a population.
Natural selection, the mechanism by which species evolve over time, is depicted in the flowchart.
Overproduction of offspring causes competition for limited resources, resulting in a struggle for survival.
Based on their inherited characteristics, some people are better equipped to survive and reproduce than others.
These people are said to be "fit," and they are more likely to pass on their positive traits to their children. These advantageous traits become more common in the population over time, causing changes in the species as a whole.
Thus, the correct option is 4.
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Your question seems incomplete, the probable complete question is:
What connections are there between the changing surface of the Earth and the evolution of life?
Please help!!
Evolution is the modification of heritable traits. The change in the earth's surface is directly linked to evolution as the formation of the species, abiotic factors, and gases happened due to changes.
What is evolution?
Evolution is the adaptation and survival of the modified organism due to changes in favorable environmental conditions. It is an important factor governed by natural selection.
The evolution and the change in the earth's surface are interconnected as the changes in the earth's crust made the presence of the living beings possible. The conditions at early times were unfavorable that underwent many changes till the present scenario.
The atmosphere and crust were unfavorable for the living beings that got changed and improved with oxygen quality, water, and the crust for the organism to exist, survive and reproduce to continue their lineage.
Therefore, evolution is linked to changing the earth's surface.
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What is the control for “which bait works best for a homemade fly trap?”
Answer:
A glass of water or an empty cup
Explanation:
If no flies are attracted, that means your experiment is not flawed.
What is the difference between sediments deposited in outwash and sediments deposited in moraines?
1. Sediments in the outwash are larger.
2. Sediments in the outwash are sorted
3. Sediments in the outwash are more angular
4. Sediments in the outwash are older.
Answer:
2. Sediments in the outwash are sorted
The difference between sediments deposited in outwash and sediments deposited in moraines is that-Sediments in the outwash are sorted. Therefore, the correct option is 2.
What is the sediment of outwash and moraines?Outwash is the sediment that is carried away from a glacier by meltwater and deposited in streams and rivers. This sediment is typically well-sorted, which means that particles are relatively uniform in size, shape, and composition.
Moraines are piles of unsorted sediment that are left behind by a glacier as it retreats. This sediment is typically a mix of different particle sizes, shapes, and compositions.
The glacier's movement is not strong enough to sort the sediment of moraines, so it remains unsorted. Therefore, the correct option is 2.
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A person who has allergies has a compromised immune system because the body's immune system
attacks its healthy cells.
overreacts to an antigen.
steals nutrients from healthy cells.
responds to mutagens.
Answer:
overreacts to an antigen
Name two organs that are made up of all four tissues?
Heart and lungs are the two organs that are made up of all four tissues. secretion, movement, strength, excretion and communication are the main functions of tissues.
What are tissues in human body?Tissues are the same type of group of cells which have the same structure and functions together in a unit. Connective tissue, epithelial tissue, muscular tissue, and nerve tissue are the four fundamental forms of tissue. Other tissues are held together and supported by connective tissue bone, blood, and lymph tissues.
All body surfaces are covered in epithelial tissues, which also line bodily cavities and hollow organs and make up the majority of glandular tissue. Connective tissues are presents in the blood cells in the human body. Loose connective tissue, adipose tissue, dense fibrous connective tissue, elastic connective tissue, cartilage, osseous tissue, and blood are further more tissues in the body.
Thus, Heart and lungs are the two organs that are made up of all four tissues.
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According to the cell theory, which describes cells?
Answer:
Living organisms are not created spontaneously
Explanation:
All living organisms are made out of cells, cells are the basic unit of life, and cells come from preexisting cells
Which of the following is NOT an argument used against genectically modified food?
(A) It is new technology that unnaturally breaks genetic barriers between species
(B) It might cause allergic reactions
(C) Humans should not be designers of life
(D) All of these arguments are used
Answer:
(D) All of these arguments are used
