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.
Give a reason why lack of roughage in diet often lead to constipation?
Answer:
Roughages increase fecal volume and promote peristalsis
Explanation:
Constipation refers to the condition in which bowel evacuations occur infrequently, leading to health problems. Some of the most common causes of constipation include 1-insufficient intake of dietary fibers or roughages, 2-poor hydration, 3-lack of physical exercise, 4-abuse of laxatives, etc. Dietary fibers are divided into two classes based on their water solubility: soluble and insoluble. These fibers represent the part of plant foods that the body can't digest, which absorbs and retains water (soluble fibers) as foods pass through the bowel and create bulk (insoluble fibers), thereby leading to regular bowel habits.
According to the graph, which region is expected to reach a population of 50 million people in the year 2040?
According to the graph, the regions that are expected to reach a population of 50 million people in the year 2040 are (A). Mexico, Central America, the Caribbean island, and South America.
What is a population graph?A population graph is a type of graph that represents the distribution of population, increase or decrease of population of different areas or countries.
This population graph shows the population of different countries, some countries already reached 50 million. The countries which will be reached are in the purple line on the graph that are Mexico, Central America, the Caribbean island, and South America.
Thus, option (A), Mexico, Central America, the Caribbean island, and South America will have 50 million people in the year 2040.
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If an individual has trisomy resulting in Down syndrome and has an extra chromosome in each cell, what mutation must have occurred?
A. A nondisjunction mutation in the gamete of one of the parents
B. A nondisjunction in both gametes of the parents
C. A nondisjunction in one of the first gamete cells of the individual
D. A nondisjunction mutation in body cells of both parents
Answer:
if An individual has an extra chromosome in every one of its cells, the mutation that must have occurred is A non-disjunction mutation in the gamete of one of the parents
If an individual has trisomy resulting in Down syndrome and has an extra chromosome in each cell, the mutation that must have occurred is A. A nondisjunction mutation in the gamete of one of the parents.
Down syndrome simply means a genetic disorder that is caused when there's an abnormal cell division that then leads to extra genetic material.
The effect of Down syndrome is the fact that it leads to an intellectual disability, developmental delays, and a distinct facial appearance.
The mutation that has occurred with someone that has a Down syndrome is the nondisjunction mutation in the gamete of one of the parents.
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What is the function of the enzyme RNA polymerase during transcription?
helps slow down the process of transcription
helps speed up the process of transcription
aids in destroying the mRNA sequence that was read
aids in packaging amino acids for use at a later time
Answer:
The correct answer is - helps speed up the process of transcription.
Explanation:
RNA polymerase binds to the DNA sequence and copy a single DNA sequence into RNA and helps a single gene to produce hundreds or even thousands of RNA molecules during transcription.
It helps in the speed up the transcription by copying the sequence and producing mRNA for translation process later.
Answer:
I hope this helps.
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.
nitrogenous base + sugar + phosphate group =
Answer:
Nucleoside
Explanation:
Nucleotide is an organic compound which is made from of nitrogenous base, a sugar, and a phosphate group.
Sometimes the most practical way to do an experiment is not to perform it in an animal, but to look at cell responses in culture. Cells from mice, humans, and other mammals have been used to establish cell culture lines that have been very important for research. You are studying a novel water-soluble mouse hormone. You know cell culture can be a practical model to reveal protein function, so you apply the hormone to yeast cells, but nothing happens. What is a likely explanation for why nothing happened in your experiment
Answer:
Yeast cells likely do not have receptors that bind to this specific water-soluble mouse hormone
Explanation:
Receptors are molecules capable of binding specific signaling molecules (i.e., ligands). For example, steroid receptors can only bind to specific steroid hormones (e.g. estrogen, progesterone). Plasma membrane receptors are protein receptors that bind to water-soluble ligands. These receptors are embedded in the cell plasma membrane and usually contain several transmembrane domains. Examples of cell membrane receptors include G protein-coupled receptors (GPCRs), enzyme-linked protein receptors and ion channel receptors.
What are threatened species?Question 1 options: species we do not have enough data for to determine their population numbers only large mammals like elephants, pandas, and whales only species poached for their organs or other parts species at risk for extinction species that have already gone extinct
Answer:
The correct answer is - species at risk for extinction.
Explanation:
Extinction is a threat to species of any living organism. The death or removal of last individual of a species is the condition of extinction.
It is commonly referred to the species as mostly species extinct from earth. Any size or type of species of living organism can be extinct.
In which order will free nucleotides add on to a single strand of DNA with the sequence ATTGCA during DNA replication? (2 points) O Uracil, adenine, adenine, cytosine, guanine, uracil Adenine, thymine, thymine, guanine, cytosine, adenine Thymine, adenine, adenine, cytosine, guanine, thymine O Guanine, cytosine, cytosine, adenine, thymine, guanine
Adenine, thymine, thymine, cytosine, guanine, and adenine is the correct order in which nucleotides add on single strand DNA.
What is DNA replication?The process of DNA replication is crucial for cells to divide and create an exact copy of their DNA. Enzymes like helicase play a vital role in unwinding and separating the two strands of the double helix, creating a replication fork that serves as the starting point for this process. As DNA polymerase adds nucleotides to the new strand using the existing strand as a template, it follows specific rules of complementary base pairing: adenine (A) pairs with thymine (T), while cytosine (C) pairs with guanine (G).
What will be order of nucleotides to add on single strand of DNA?During DNA replication, the order in which free nucleotides will add on to a single strand of DNA with the sequence ATTGCA is crucial. The correct sequence of nucleotides that will bind to this template strand is adenine (A), thymine (T), thymine (T), cytosine (C), guanine (G) and adenine (A). This follows the complementary base pairing rules where A pairs with T and C pairs with G. By following these rules, the newly synthesized strand will have a correct sequence of ATTTGC, ensuring accurate replication.
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select the correct answer from each drop down menu.
both anaerobic and aerobic respiration use __ to produce ATP and NADH
define and describe osmosis
Answer:
Movement of a solvent (such as water) into a solution with a higher solvent concentration by means of a semi-permeable membrane (as from a live cell), which tends to equal solute concentrations in the membrane on both sides.
Explanation:
Osmosis, the spontaneous transition, distribution, or diffusion of water and other solvents over a semipermeable membrane. In 1877, a German physiologist, Wilhelm Pfeffer, researched the process, which is important in biology.
Osmosis is the passage of water down its concentration gradient, across a semi-permeable membrane. An everyday example is a plastic wrap in your kitchen: it allows air and water vapor to move across it, but no water or food. The membranes of cells are semi-permeable, too.
Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is ________. less than the pressure in the atmosphere greater than the intra-alveolar pressure greater than the pressure in the atmosphere equal to the pressure in the atmosphere
Answer:
Air moves out of the lungs when the pressure in the lungs is greater than the pressure in the atmosphere.
How do bryophytes differ from tracheophytes?
Answer:
The main difference between bryophytes and tracheophytes is that bryophytes are nonvascular plants, whereas tracheophytes are vascular. Mosses, liverworts, and hornworts are examples of bryophytes, whereas ferns, gymnosperms, and angiosperms are examples of tracheophytes
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During diffusion, molecules move from areas of blank concentration to areas of blank concentration. Diffusion does not require blank to move molecules.
Answer:
high; low; energy.
Explanation:
Diffusion can be defined as the movement of gas molecules from a region of high concentration to a region of lower concentration until an equilibrium is attained or reached. This mixing of gas molecules in the liquid or gaseous state is due to their kinetic energy of random motion i.e without requiring bulk motion.
This ultimately implies that, diffusion is a phenomenon through which gas molecules in either a gaseous or liquid state spread out in response to a concentration gradient, which is simply the difference in concentration of the gases across a space.
During diffusion, molecules move from areas of high concentration to areas of low concentration. Also, diffusion does not require energy to move molecules.
In conclusion, increasing the surface area of a gas increases its collision rate and it's considered to be an evolutionary strategy that maximizes the diffusion of gas molecules because it catalyzes the rate of a gaseous reaction.
what do you mean by components of mixture?
Answer:
The components of a mixture are the items that are mixed together.
Explica brevemente en que consiste la teoría de la deriva continental y menciona los contenientes que se crearon a partir de la Pangea
Esta teoría hace referencia al movimiento actual de las placas que sustentan los continentes y que se desplazan a lo largo de millones de años. En toda la historia geológica de la Tierra, los continentes no han estado siempre en la misma posición. Existe una serie de evidencias que veremos posteriormente que ayudaron a Wegener a refutar su teoría. El movimiento se debe a que continuamente está formándose nuevo material procedente del manto. Este material se crea en la corteza oceánica
Which of the following factors does not affect soil formation?
a. precipitation
b. time
C. erosion
d. none of the above
Please select the best answer from the choices provided
B
Ο Ο Ο Ο
PLS HELP ASAP
Answer:
b is the answer
Explanation:
edge2021
Question 8 of 10
A biologist measures the allele frequencies of pea plants in a very controlled
environment. The plants can either have a dominant tall allele (7) or a
recessive short allele (t). Which of the following would be a reason that this
population is not at Hardy-Weinberg equilibrium?
O A. There are no mutations in the alleles for height.
B. Tall plants are more likely to survive.
O c. All of the pea plants reproduce exactly once.
O D. The pea flowers are pollinated at random.
Answer:
C. Tall plants are more likely to survive (
Explanation:
Plants and algae most recently shared a common ancestor 480 million years ago, and plants colonized land shortly after that. Light, water, minerals, and dissolved gases surround the whole body of a submerged green alga, and the buoyancy of water provides physical support. What part did plants evolve to absorb water and minerals on dry land
Answer:
vascular tissues
Propose advantages and disadvantages of nuclear energy as an energy source.
Answer:
Advantages:
Produces no polluting gases.
Does not contribute to global warming.
Very low fuel costs.
Low fuel quantity reduces mining and transportation effects on environment.
High technology research required benefits other industries.
Disadvantages:
Waste is radioactive and safe disposal is very difficult and expensive.
Local thermal pollution from wastewater affects marine life.
Public perception of nuclear power is negative.
Costs of building and safely decommissioning are very high.
Cannot react quickly to changes in electricity demand.
Which equation represents fertilization?
haploid + diploid = diploid
diploid + haploid = haploid
haploid + haploid = diploid
diploid + diploid = diploid
Answer:
the answer is (C) haploid + haploid = diploid
Explanation:
edge 2021
Haploid+ Haploid = Diploid represents fertilization. So, the correct option is (C).
What is Fertilization?
Fertilization is defined as the process in which two gametes where one male and one female first form a zygote and then lead to the development of an embryo.
These germ cells are cells that give rise to gametes – either egg cells that are female gametes or sperm cells that are male gametes.
These germ cells are the only cells that can undergo both mitosis and meiosis. These are the diploid cells present in the gonads. After meiosis, haploid gametes are produced. In fertilization two haploid gametes fuse (n+n) and form a diploid zygote (2n)
Thu, Haploid+ Haploid = Diploid represents fertilization. So, the correct option is (C).
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Which of these factors would most likely strengthen the effectiveness of
Answer:
Which of these factors would most likely strengthen the effectiveness of CITES?
Answer: Funding for on-the-ground enforcement
describe the role of enzymes in seeds germination
anyone please help me
Answer:
b b
B Bb Bb
b bb bb
if the brown mail had been BB then all offspring would have been Bb and all brown however is the male is Bb as above and you perform a test cross 50% of all Offspring should have the bb genotype and a white phenotype a testcross to a heterozygous individual should always yield about a one-to-one ratio of the dominant or recessive phenotype so both of the genotypic and phenotypic ratios here are 50/50
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Why is it essential for SARS-CoV2 RNA be translated on ribosomes before it can be replicated?
The SARS-CoV-2 non-structural protein 1 (Nsp1), also referred to as the host shutoff factor, suppresses host innate immune functions. By combining cryo-electron microscopy and biochemistry, we show that SARS-CoV-2 Nsp1 binds to the human 40S subunit in ribosomal complexes, including the 43S pre-initiation complex and the non-translating 80S ribosome. The protein inserts its C-terminal domain into the mRNA channel, where it interferes with mRNA binding. We observe translation inhibition in the presence of Nsp1 in an in vitro translation system and in human cells.
Science is not a process, but just a body of facts that
accumulates overtime.
TRUE
FALSE
Answer:
False
Explanation:
Science is more about gaining knowledge than it is about simply having knowledge. Science is a way of learning about the natural world that is based on evidence and logic. In other words, science is a process, not just a body of facts. Through the process of science, our knowledge of the world advances.
In plants, most differentiated cells retain Group of answer choices a complete set of their genes and retain the ability to express those genes under certain circumstances. a complete set of their genes but lose the ability to express most of those genes. only a tiny fraction of their original set of genes. the ability to dedifferentiate but then cannot return to their original differentiated state.
Answer:
due to their excessive numbers in tissues. ... because their developmental potential is limited to certain tissues. In plants, most differentiated cells retain. A) only a tiny fraction of their original set of genes.
Explanation:
hmm i think this is your answer
Give the functions of the following parts of the respiratory system - Nostril - trachea - bronchiole - alveoli - pharynx - larynx - lungs - ribs - diaphragm
Answer:
Respiratory System: The respiratory system's main job is to move fresh air into your body while removing waste gases.
Nostril: To warm air on inhalation and remove moisture on exhalation.
trachea: Serves as passage for air, moistens and warms it while it passes into the lungs, and protects the respiratory surface from an accumulation of foreign particles.
bronchiole: To deliver air to a diffuse network of around 300 million alveoli in the lungs.
alveoli: To exchange oxygen and carbon dioxide molecules to and from the bloodstream during breathing.
pharynx: Helps the respiratory system by allowing air to make its way to the respiratory tract.
larynx: Produces vocal sounds and prevents the passage of food and other foreign particles into the lower respiratory tracts.
lungs: To help oxygen from the air we breathe enter the red cells in the blood.
ribs: To aid respiration and help protect the lungs.
diaphragm: Contracts and flattens when you inhale. Creates a vacuum effect that pulls air into the lungs, and relaxes when exhaling.
Is the Use of energy to move particles against the concentration gradient
Answer:
During active transport, substances move against the concentration gradient, from an area of low concentration to an area of high concentration. This process is “active” because it requires the use of energy (usually in the form of ATP). It is the opposite of passive transport.
In the scientific process, what is the correct sequence for the following steps: A: Recognizing a problem/Asking a question; B) Testing a hypothesis; C Drawing inferences
Group of answer choices
ABC
ACB
CAB
BCA
Answer:
ABC
Explanation:
Ask questions, make a hypothesis, test the hypothesis, analyze results, draw conclusions, communicate results.
