Answer:
C The sarcomere is contracted, and the actin and myosin filaments are completely overlapped.
Explanation:
In rest, the tropomyosin inhibits the attraction strengths between myosin and actin filaments. Contraction initiates when an action potential depolarizes the inner portion of the muscle fiber. Calcium channels activate in the T tubules membrane, releasing calcium into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to troponin C, troponin T alters the tropomyosin position by moving it and unblocking the binding sites. Myosin heads join the uncovered actin-binding points forming cross-bridges, and while doing so, ATP turns into ADP and inorganic phosphate, which is released. Myofilaments slide impulsed by chemical energy collected in myosin heads, producing a power stroke. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Finally, Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
In the sarcomere, which is the contractile unit of skeletal muscles, there are
Thick myosin myofilaments in the central region belonging to the A band. Thin filaments united to the Z lines, extending in the interior of the A band until they reach the border of the H band. Thin actin filaments composing the I band, which belong to two sarcomeres adjacent to a Z line.When the muscle contracts, the muscular fiber gets shorter and thicker due to the reduction in the length of the sarcomere. The H line and the I band get shorter. The Z lines get closer to the A band, meaning that they get closer to each other. A band keeps constant in length. This change is produced by movement mechanisms that involve a change in the relative position of actin and myosin filaments.
Answer:
C
Explanation:
edge 2021
The two parts of cellular respiration which must occur twice for each glucose molecule that enters the process are
Answer:
the citric acid cycle and preparatory steps
The image below shows one of the earliest stages of DNA replication. What
role does helicase play in DNA replication?
A. Helicase breaks the hydrogen bonds and unwinds a section of DNA.
B. Helicase connects the floating nucleotides to the template strands.
C. Helicase checks the base pairs in each new strand of DNA.
D. Helicase bonds together pieces of DNA as new strands form.
Answer:DNA helicases are also called molecular motors. They unwind the DNA with the help of ATP hydrolysis, and thus facilitate the replication and transcription processes. ... Studies have suggested that DNA helicases may play a role in plant DNA recombination, as it is prominent during the meiotic prophase of plants.
Explanation:
Role played by Helicase in DNA Replication is to break down the hydrogen bonds and unwinds a section of DNA.
What is DNA?
DNA, or deoxyribonucleic acid, is the hereditary material in humans located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).
Mitochondria are structures within cells that convert the energy from food into a form that cells can use.
The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people.
The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
What is DNA Replication?In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule.
DNA replication occurs in all living organisms acting as the most essential part for biological inheritance and it is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA.
The cell possesses the distinctive property of division, which makes replication of DNA essential.
DNA is made up of a double helix of two complementary strands. The double helix describes the appearance of a double-stranded DNA which is composed of two linear strands running opposite to each other and twist together to form.
During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication.
As a result of semi-conservative replication, the new helix will be composed of an original DNA strand as well as a newly synthesized strand.
Cellular proofreading and error-checking mechanisms ensure near perfect fidelity for DNA replication.
What is the role of Helicases in DNA Replication?Helicases are enzymes that bind and remodel nucleic acid or nucleic acid protein complexes.
Helicases are of two types- DNA Helicases and RNA Helicases.
Role of Helicases:
- Separate the double stranded DNA into single one to allow copying.
- Initiate synthesis at the origin of unwinding
- Helicases use the energy stored in a molecule called ATP, which serves as the energy currency of cells, to break the bonds.
- DNA helicases also function in other cellular processes where double-stranded DNA must be separated, including DNA repair and transcription.
- RNA helicases are involved in shaping the form of RNA molecules, during all processes involving RNA, such as transcription, splicing, and translation.
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Explain how fluctuations in abiotic cycles can influence populations.
Answer:
Populations are influenced by fluctuations in any of the abiotic cycles. The fluctuation of seasonal cycles can cause populations to hibernate, migrate, or breed. Organisms hibernate as a result of seasonal fluctuations that cause them to have a limited resource supply.
Blood banks dispose of blood that has low levels of bisphosphoglycerate. What would be the probable reason for doing so
Answer:
Erythrocytes low in BPG does not unload O2 very well.
Select the correct answer. Which statement correctly explains the polarity of the water molecule? A. The hydrogen end of the molecule has a partial negative charge and the oxygen end has a partial positive charge. B. The oxygen end of the molecule has a partial negative charge and the hydrogen end has a partial positive charge. C. Both ends of the molecule have a partial negative charge, which attracts the other water molecule towards itself.
Answer:
option B) The oxygen end of the molecule has a partial negative charge and the hydrogen end has a partial positive charge.
Justification:
The electronegativity of an element accounts for its relative ability to attract electrons.
Being oxygen more electronegative than hdyrogen (the electronegativity of oxygen is 3.44 while the electronegativity of the hydrogen is 2.20), the electron density will be displaced toward the oxygen, letting it with a partial negative charge and the hydrogen with a partial positive charge.
Finally, since the charge is not symmetrical distributed around a center of the molecule, the molecule ends being polar.
N a garden with trees and shrubs, green and pink katydids were observed. Over time, birds started feeding on the katydids. Which two statements describe what will eventually happen to the population of the katydids?
Answer: A.The population of pink katydids will decrease.
B.The population of green katydids will decrease.
Explanation:
The two statements describe what will eventually happen to the population of the katydids are that:
• A.The population of pink katydids will decrease.
• The population of green katydids will decrease.
This is because from the information given, since birds started feeding on the katydids, this will result in the reduction in the number of katydids. Hence, the decrease in both the pink and the green katydids.
Answer: A: The population of pink katydids will decrease.
C: The population of green katydids will increase.
Explanation: The birds that feed on the Katydids will see the pink ones due to the green ones being camoflauged. The pink katydids will decrease and the green katydids will increase.
The great hornbill and the toucan both eat the same fruit, insects, and nuts. They both live in the rainforest. Their large bills function to get food and also as warning coloration. Which of the following is a limiting factor to the toucan population?
overlapping breeding seasons
bill coloration
genetic variability
competition
The correct answer is D. Competition.
Explanation
A limiting factor is a term that refers to the scarcity factor of a resource that limits the development and evolution of a specific species or process. According to what is described in the question, it can be inferred that the limiting factor of toucans is competition because the great hornbill lives in the same tropical forest as the toucan, it feeds on the same foods as the toucan: fruit, insects, and walnuts. So, competition for the same resources is a limiting factor for toucans since the absence of food can affect their development. So the correct respect is the D. Competition.
The cells in this part of a plant form long, vertical tubes. What is the most
likely relationship between the structure and function of these specialized
cells?
O A. The tubes allow water and nutrients to be transported throughout
the plant.
O B. The tubes prevent potential damage to the leaves caused
used by
strong winds.
C. The tubes allow the plant to absorb sunlight for photosynthesis.
O D. The tubes prevent water loss from the leaves.
Answer:
xylem and pholem.....?
When amino acids are degraded for energy or glucose production, their amine groups are incorporated by the liver into ____.
Answer:
The correct answer is - urea.
Explanation:
In our body, to produce energy or produce glucose our body breaks the amino acids, it gets from proteins mainly. These amino acids are mainly breakdown into amine groups.
The human body has a unique ability to pack ammonia(amine group) by converting it to urea and incorporated and produced by the liver using 2 molecules of ammonia (NH3) and 1 molecule of carbon dioxide (CO2). This incorporated urea is then secreted from the liver and incorporated into the urine in the kidney for further process.
Mendel used more than 28,000 pea plants in his experiments. Why is it important that he studied such a large sample of pea plants?
A. The pea plants were very inexpensive.
B. Most pea plants die after producing seeds.
C. Having more samples gave him results that were closer to the predicted ratios.
D. Using more plants made the experiments take less time.
Having more samples gave him results that were closer to the predicted ratios.Mendel's experiments involved studying the inheritance of traits in pea plants. By carefully crossing different varieties of pea plants and observing the traits of their offspring, he was able to formulate the laws of inheritance that are still used today.
What does Mendel's experiments involves?Mendel's experiments involved observing the inheritance of traits in pea plants, which were controlled by genes.
By studying a large sample size of 28,000 pea plants, he was able to obtain data that was much more reliable and accurate. This is because the larger the sample size, the closer the results will be to the expected outcomes or predicted ratios, and any anomalies or errors would be minimized.
This is an important principle in statistics and scientific research, and it helps to ensure the validity and generalizability of the findings.
Additionally, by using such a large number of plants, Mendel was able to minimize the impact of any outliers or anomalous results that might have occurred in a smaller sample. This helped to ensure that his results were as accurate and reliable as possible.
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Why do some species of predators appear
intimidating?
A. The adaptations they possess for hunting and eating
make them look intimidating.
B. Some predators can scare their prey into giving up
without a fight.
C. Predators do not appear intimidating.
Answer:
A. The adaptations they possess for hunting and eating make them look intimidating.
Explanation:
Some species of predators appear intimidating because of the adaptations they possess for hunting and eating make them look intimidating and fearful. The appearance of some predators make them intimidating which make the prey full of fear. For example, Lion is intimidating other animals especially its prey due to its attitude as well as physical appearance such as big sharp teeth and paws etc.
PLEASE PLEASE HELP ME WITH THIS PLEASE PLEASE HELP NOW PLEASE GOD PLUS YOU PLEASE please Help me please
Answer:
Sorry ...
Explanation:
Unfortuntely, you can only answer this question if you've read the book. Those reading this pretty much haven't.
There are sixty-one mRNA codons that specify an amino acid, but only forty-five tRNAs. This is best explained by the fact that
Answer:
See the answer below
Explanation:
The phenomenon is best explained by the fact that the genetic codes are degenerates. In other words, more than one codon can specify for the same amino acid being carried by the tRNA.
The base-pairing rule between the third nucleotide of a codon and that of the anticodon on the tRNAs loosens off. For example, GUU, GUC, and GUA all specify for the amino acid valine while GCU, GCC, and GCA all specify for alanine.
‼️⁉️need answer ASAP ‼️⁉️Which property describes a mixture? Cannot be separated by physical methods. It has a Single Chemical composition. It cannot have more than one state of matter. It cannot be described by a chemical symbol or formula.
Answer: It cannot be described by a chemical symbol or formula
Explanation:
A mixture isn't chemical-- it's purely physical. So, no chemical symbol or formula could be used to describe it.
what a meteor is called before it enters Earth’s atmosphere
Answer:
A meteor, before entering earth's atmosphere is known as a meteoroid
Compare and contrast the cell structures / organelles found in plant and animal cells.
list 3 organelle/structures plant and animal cells have that are the same
list 2 organelles/structures plant and animal cells have that are different
Answer:
They both have a cell membrane.
they both have a nucleus
they both have the endoplasmic reticulum
Explanation:
One has a cell wall
one has a big vacuole and the other have many little vacuoles
in your own words, what is the definition for Lysine?
can someone go to my profile and write the definitions in your own words that I posted today? there are 4 of them and I can give you brainliest for each of them since there would be more than one person.
Thank you!
Answer:
ok i go
Explanation:
your experience is so so good and your frofile
which of the following structures helps our sense of balance
Answer:
D answer is correct
Explanation:
semi circular helps our sense of balance
Answer:
eardrum
Explanation:
The ear is a sensory organ that picks up sound waves, allowing us to hear. It is also essential to our sense of balance: the organ of balance (the vestibular system) is found inside the inner ear. It is made up of three semicircular canals and two otolith organs, known as the utricle and the saccule
During glycolysis, glucose is broken down into two molecules of pyruvate.
A diagram shows the conversion of a glucose molecule to 2 pyruvic acid molecules. In this process, 2 A T P form 2 A D P, 2 N A D produce 2 N A D H, and 4 A D P produce 4 A T P.
What is the main transformation that occurs during glycolysis?
Glycolysis produces ATP and pyruvate by oxidizing water.
Glycolysis produces ATP and pyruvate by oxidizing glucose and NAD+.
Glycolysis produces pyruvate, ATP, and NADH by oxidizing glucose.
Glycolysis produces CO2, ATP, and pyruvate by reducing glucose.
Answer:
Glycolysis produces pyruvate, ATP, and NADPH by oxidizing glucose. During cellular respiration, glucose combines with oxygen to form carbon dioxide, water, and ATP.
Explanation:
Answer:
C.
Explanation:
if masquiteos have babys in water then can the have babbies in fog
Maybe, mosquitoes lay eggs in still water like a in pail or bucket
Identify the organelles in the cell to the right.
Answer:
which one?
i dont see anyting on the right
Answer:
Explanation:
e
Identify the structures in the cell pictured on the right:
Label A
Label B
Label C
Label D
Label E
Options:
1.DNA
2.Nucleus
3.Cytoplasm
4.Cell Membrane
5.Ribosomes
Answer:
1d
2a
3b
4e
5c
is the correct answer for questions
Answer:
B
C
E
A
D
Explanation:
correct edg 2021
what statement is true for both photosynthesis and cellular respiration?
A. it occurs in consumers?
B. it occurs in producers
C. it produces carbon dioxide
D. it produces oxygen
Which of the following is not true about hydrothermal vents?
A. They provide a look into what ancient life may have looked like.
B. They contain chemosynthetic organisms.
C. They cannot contain life of any sort.
D. They are found in volcanic areas under the ocean.
C, because that would contradict observations
Answer:
its (c) cz....
Explanation:
The floor of the deep ocean is almost devoid of life, because little food can be found there. But around hydrothermal vents, life is abundant because food is abundant. ... These vents are the only places on Earth where the ultimate source of energy for life is not sunlight but the inorganic Earth itself. hope it helps u I tried my best.pls mark me as branliestA student collects some of the solution from the phloem in the stem of a plant. Which of the following would be present in the liquid?
A) Glucose
B) Starch
C) Amino Acids
D) Cellulose
HELP!!!
Answer:
D
Explanation:
What can our nerves respond to?
They can respond to external stimuli
Many antibiotics work by preventing the proper synthesis of the peptidoglycan cell wall. These antibiotics are most likely to be effective against what types of bacteria
Answer: Gram-positive bacteria.
Explanation:
Gram-positive bacteria are those bacteria that stain dark blue or violet by Gram staining. This is due to the structure of the cell envelope, since they possess a cell wall composed of a thick layer of peptidoglycan, which surrounds the previous one. The cell wall is attached to the cytoplasmic membrane by lipoteichoic acid molecules. The peptidoglycan layer confers high resistance to these bacteria and is responsible for retaining the stain during Gram staining. Unlike gram-positive bacteria, gram-negative bacteria have a second lipid membrane outside the cell wall and a single peptidoglycan layer.
An antibiotic is a chemical substance produced by a living being or synthetically derived, which kills or prevents the growth of certain classes of sensitive microorganisms, such as bacteria. An antibiotic could be bacteriostatic if it prevents the growth of bacteria or bactericidal if it destroys them.
Antibiotics usually attack cell walls, such as β-lactams that act on the peptide chains of the bacterial cell wall. That is, they act by inhibiting peptidoglycan synthesis. This is why gram-positive bacteria are susceptible to certain types of antibiotics because they possess a large amount of peptidoglycan.
What m-RNA strand would be formed from the DNA strand below?
T G A C G T A
A C T G C A T
Answer:
A C U G C A U U G A C G U A
Explanation:
because Adenine always pairs with Uracil and guanine with cytosine. you can also remember it as Apple Tree and Car Garage.
A man cannot be a carrier for hemophilia. Why?
Answer:
This means that males only have one copy of most of the genes on the X chromosome, whereas females have 2 copies. Thus, males can have a disease like hemophilia if they inherit an affected X chromosome that has a mutation in either the factor VIII or factor IX gene.
