what is cell wall ?

please help.​

Answers

Answer 1

Answer:

A cell wall is a structural layer found just outside the cell membrane that surrounds various types of cells. It may be robust, flexible, and even stiff at times. It functions as a filtration mechanism as well as providing structural support and protection to the cell.


Related Questions

How do you think genomics and genetic engineering will contribute to the development of more productive food crops and what ecological implications should be considered? Be sure to include examples of existing and future GMOs that are contributing to the debate. What are the main criticisms of the Green revolution, and how can we mitigate some of the negative aspects? Cite your work

Answers

Answer:

The importance of optimal nutrition for human health and development is well recognised. Adverse environmental conditions, such as drought, flooding, extreme heat and so on, affect crop yields more than pests and diseases. Thus, a major goal of plant scientists is to find ways to maintain high productivity under stress as well as developing crops with enhanced nutritional value. Genetically-modified (GM) crops can prove to be powerful complements to those produced by conventional methods for meeting the worldwide demand for quality foods. Crops developed by genetic engineering can not only be used to enhance yields and nutritional quality but also for increased tolerance to various biotic and abiotic stresses. Although there have been some expressions of concern about biosafety and health hazards associated with GM crops, there is no reason to hesitate in consuming genetically-engineered food crops that have been thoughtfully developed and carefully tested. Integration of modern biotechnology, with conventional agricultural practices in a sustainable manner, can fulfil the goal of attaining food security for present as well as future generations.

Explanation:

Question 17 of 30
15 ~ 94%
Complete the following sentence. Iron usually forms only an _____
magnet that loses its
magnetism when moved away from a magnetic source. What one word completes the sentence?
Enter your answer

Answers

Answer:

Iron usually forms an

Induced magnet

Answer:

Temporary or Induced Magnets.

Explanation:

Temporary magnets: These magnets are made of soft iron that has temporary magnetic properties. These magnets behave as permanent magnets when introduced to a magnetic field but lose magnetism when moved away from the magnetic source.Temporary magnets are usually used in radio, electric motors, phones.They are extensively used as electromagnets to produce electricity. The demagnetizing property of electromagnets by altering the intensity of electric current helps in a lot of practical applications based on controlled situations.

For more information:

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Sort the steps of digestion in order from beginning to end.

- The stomach kills some bacteria and breaks food down into chyme.
- Nutrients from dissolved food are absorbed from the small intestine into the bloodstream.
- Water and nutrients are absorbed by the large intestine; chyme becomes waste matter.
- Saliva mixes with food and changes starches into sugars.

Answers

- Saliva mixes with food and changes starches into sugars.

- The stomach kills some bacteria and breaks food down into chyme.

- Nutrients from dissolved food are absorbed from the small intestine into the bloodstream.

- Water and nutrients are absorbed by the large intestine. Chyme becomes waste matter.

Saliva mixes with food and changes starches into sugars is the beginning step of the digestion.

What are the functions of saliva?

Saliva is the medium that bathes the taste receptors in the oral cavity and in which aroma and taste compounds are released when food is eaten.

It is composed of water, mucus, proteins, mineral salts, and amylase. As saliva circulates in the mouth cavity it picks up food debris, bacterial cells, and white blood cells.

Saliva moistens the mouth for comfort, lubricates as you chew and swallow, and neutralizes harmful acids. It also kills germs and prevents bad breath, defends against tooth decay and gum disease, protects enamel, and speeds up wound healing.

Learn more about saliva:

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a permanent disease process that is characterized by destruction of the alveolar walls and distention of the alveolar sacs is a type of COPD called

Answers

Answer:

Emphysema

Explanation:

Pulmonary emphysema disease progressively destroys the fibers that promote respiration, leading to a decrease in respiratory function, emphysema being a more serious complication of any bronchopulmonary obstructive inflammation. In emphysema, the walls that separate many of the alveoli are damaged and gas exchange in the lungs decreases. This disease originates when the pulmonary alveoli are progressively destroyed and difficulty in breathing becomes greater and greater. When destroyed, a larger space is created, instead of small chambers. And this affects the length of the lungs and the amount of oxygen that reaches the blood.

Mycoplasmas which belong to Firmicutes are pleomorphic because: (2 pts) they have no cell walls they are low G C content Gram-positive bacteria they exhibit snapping division they reproduce asexually they produce endospores

Answers

Answer:

they have no cell walls.

Explanation:

Mycoplasmas that belong to Firmicutes are considered as pleomorphic because they have no cell walls in their structure. Mycoplasmas have the following characteristics i.e. the smallest mycoplasmas are 125–250 nm in size, they are highly pleomorphic because they lack a rigid cell wall and instead of cell wall they are bounded by a triple-layered “unit membrane” that contains a sterol in its structure.

n
Which statement best describes the step in muscle contraction when the sarcomere is the shortest?
A The sarcomere is contracted, and the actin and myosin filaments are partially overlapped.
B The sarcomere is relaxed, and the actin and myosin filaments are partially overlapped.
C The sarcomere is contracted, and the actin and myosin filaments are completely overlapped.
D The sarcomere is relaxed, and the actin and myosin filaments are completely overlapped.

Answers

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

Amy, a high-strung teenager, was suddenly startled by a loud bang that sounded like a gunshot. Her heartbeat accelerated rapidly. When she realized that the noise was only a car backfiring, she felt greatly relieved but her heart kept beating heavily for several minutes more. What hormone was released into her bloodstream that is causing this response

Answers

Answer:

Catecholamines, endothelins, glucocorticosteroids and thyroid hormones.

Explanation:

Catecholamines, endothelins, glucocorticosteroids and thyroid hormones are the type of hormones that is released into the bloodstream that causes increase of heart rate. Stress and anxiety is responsible for the raising of your heart rate. It may also increases when you're very happy or upset. People who have severe obesity can have a slightly faster pulse as compared to normal people.

True or false: Osseous connective tissue is the only tissue type found in bones. True false question. True False

Answers

Answer:

False

Explanation:

you have learnt that forest lead to groundwater recharge but don't you think that groundwater should decrease as plant would absorb lots of water?​

Answers

Answer:

No raining will refill it

hope it helps

pls mark me as the brainliest

thank u

Explanation:

When you touch an object that is very hot you quickly pull your hand back. What is the correct pathway of nerve impulses for this behavior?
A. Heat receptors in the hand, sensory neurons, brain, motor neurons, hand muscles.
B. Heat receptors in the hand, motor neurons, hand muscles, sensory neurons, brain.
C. Hand muscles, motor neurons, brain, sensory neurons, heat receptors in hand.
D. Brain, sensory neurons, heat receptors in hand, motor neurons, hand muscles.

Answers

A heat receptor>sensory neuron>brain>motor neuron>>hand muscles

Answer:

a

Explanation:

If a person uses up his or her reserve supply of glycogen and still does not eat, the body will break down ____ to provide glucose for the brain.

Answers

Answer:

carbohydrates

Explanation:

this is because even though the person hasn't eaten he or she still has an amount of carbohydrates in the body that can be broken down and its end product glucose will be obtained

The total number of molecules of ATP produced during glycolysis is ______, which results in a net production of _____ ATP.

Answers

Answer:

The answer is "4 and 2 ".

Explanation:

The overall glycolysis ATP number is 4 of one hydroxyl group. In the first part of the glycolysis 2 ATP molecules are used, so that 2 ATP molecules are net gained. 2. In addition, 2 NADH atoms in the glycol are also created. This is why the total ATP molecules produced during metabolism are 4, resulting in a net output of 2 ATP.

White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking at a sample of blood for WBCs, what could you do to reduce interference from RBCs? Group of answer choices Mix the blood in a hypotonic solution, which will cause the RBCs to lyse. Mix the blood in a hypertonic solution, which will cause the RBCs to lyse. Mix the blood in a salty solution to cause the RBCs to lyse. Mix the blood in an isotonic solution and allow the WBCs to float to the top.

Answers

Answer:

The correct option is this: MIX THE BLOOD IN A HYPOTONIC SOLUTION WHICH WILL CAUSE THE RED BLOOD CELL TO LYSE.

In order to reduce interference from red blood cell, mix the blood sample with a hypotonic solution. Because the red blood cells has more solute concentration, water from the hypotonic solution will enter into its cells and with time the cells will burst since they do not have much resistance against lysis. The bursting of the cells will eliminate the red blood cells and leave you with white blood cell to work with.

What percentage of the nation’s demand for electricity could be produced in the future by wind energy?

5 to 10 percent

25 to 30 percent

70 to 75 percent

40 to 50 percent

Answers

I think 25- 30% I’m not sure

What do all organisms need? Select three options.

Answers

Answer:

what are the options?

Explanation:

Answer:

food water a place to live

Explanation:

food, water, and protection. A plant is left in a protected greenhouse that pumps in fresh carbon dioxide. The plant also has access to sunlight and can make its own sugar. However, the plant is beginning to die.

Which layer of Earth has the highest temperatures at 5000-6000 Celsius?

Answers

Answer:

Inner Core

Explanation:

The inner core is the most inner layer of the earth. The inner core contains iron, the iron in the inner core is not pure (so not just iron) scientists believe it contains sulfur and nickel and also smaller amount of other elements. The inner core is extremely hot it is somewhere between 9000 and 13000 degrees Fahrenheit (5000 and 7000 degrees Celsius).  

explanation credit to: katnissdiv1 on weebly

Question 28 of 30
The diagram below shows part of the process of DNA transcription. Which
mRNA base will go in location 1?
DNA
TCHCIGATI
ACACAC123
mRNA
A. Uracil
B. Cytosine
C. Thymine
D. Adenine

Answers

Answer:

uracil

Explanation:

uracil is complenentary to adenine in transcription

The diagram below shows part of the process of DNA transcription. Uracil mRNA base will go in location 1.

What do you mean by DNA transcription?

The process of turning a piece of DNA into RNA is called transcription. Messenger RNA is said to be produced when DNA segments are transcribed into RNA molecules that can encode proteins.

DNA record is the cycle by which the hereditary data held inside DNA is re-composed into courier RNA (mRNA) by RNA polymerase. After that, this mRNA leaves the nucleus and serves as the foundation for DNA translation.

The nucleus is where transcription takes place. An RNA (mRNA) molecule is produced by using DNA as a template. During record, a strand of mRNA is made that is corresponding to a strand of DNA.

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A 70-year-old male presents with back pain, fever, and weight loss. He reports that he had a recent respiratory infection from which he thought he recovered. Tests revealed increased white blood cell count, and a diagnosis of endogenous osteomyelitis was made. The primary organism causing this condition is

Answers

Answer:

This question lacks options, options are:

a.Fatigue fracture

b.Stress fracture

c.Pathologic fracture

d.Greenstick fracture.  

The correct answer is c.

Explanation:

A pathological fracture is one produced in a weakened bone as a result of trauma that would not cause such an effect on bones that had their composition, resistance or flexibility properties at the correct levels, that is, a pathological fracture is any loss of bone continuity that occurs in a weakened bone, secondary this weakness to the development of a disease. Endogenous osteomyelitis is a blood-borne bacterial infection that spreads to the bone.

A phage is improperly assembled, so that it does not receive DNA within its head. What effect will this have on the phage

Answers

Answer:

The phage will not be able to infect a bacterial host cell.

Someone, please help

Answers

Answer:

i dont knwo sorry ;(((((

Explanation:

I really do not know sorry

Question 5
20 pts
If enzymes could not be used during a reaction, which of the
following could be added to a system to make the reaction occur?
O energy (possibly heat)
water
0 product
O substrate

Answers

Answer:

substrate is wright

hope it may help you

If two individuals were heterozygous for freckles, which are a dominant autosomal trait, what percentage of their offspring would you expect to have freckles

Answers

Answer:

75%

Explanation:

Firstly, an autosomal dominant trait is a trait the becomes expressed in the presence of only one affected allele, which is the dominant allele. Freckles is said to be an autosomal dominant trait meaning that the presence of the dominant allele (F) makes a person have the condition.

According to this question, If two individuals that are heterozygous for freckles cross i.e. Ff × Ff, the following proportion of offsprings will be produced: FF, Ff, Ff and ff (see punnet square).

From the genotypic observation of the produced offsprings:

FF, Ff - possess freckles

ff - do not possess freckles

Since, 3 (FF, Ff and Ff) of 4 offsprings possess freckles, the percentage of offsprings expected to have the condition will be:

3/4 × 100 = 75%

Groundwater Pollution
For Questions 17-21 write True if the statement is true. If the statement is false, replace
the underlined word or words to make the statement true. Write your changes on the
line.
17. Groundwater pollution is easy to monitor and clean up.
18. Groundwater pollution as a result of human activity is widespread.
19. Pollutants leach through soil and seep into storage tanks
20. It can take decades for groundwater to get rid of its contaminants.
21. Most efforts to reduce groundwater pollution focus on prevention

Answers

Answer:

false, false, true, false, true

Explanation:

which of the following is not classified as a pure substance a. table soft b. air c. nitrogen d. gold

Answers

The substance that is not classified as a pure substance is option a

Explanation:

table soft

One hypothesis that proposes to explain senescence notes that cells that divide throughout the life course have shortened DNA sequences at the end of the chromosomes. This is referred to as the ________ hypothesis.

Answers

Answer:

Telomere

Explanation:

The correct answer would be telomere hypothesis.

The telomere hypothesis is the main hypothesis that links aging, otherwise known as senescence, to the shortening of telomeres. Telomeres are short DNA nucleotides found at the end of each chromosome of humans.

The hypothesis postulates that loss of telomeres in the vegetative cells of the body is primarily responsible for cell aging or senescence.

Hence, the correct answer would be the telomere hypothesis.

What are the positive effects human activities on vegetation?​

Answers

Answer:

Vegetation cover is also significantly impacted by human activities. Changes in land use resulting from human activities such as urbanization and agriculture are important factors influencing the spatial pattern of vegetation.

Answer:

Vegetation plays a vital role in our natural ecosystem and also supports the biosphere in various ways; vegetation helps to regulate the flow of numerous biogeochemical cycles, most importantly those of water, carbon, and nitrogen; it also contributes in the local and global energy balances. With the continuous increase in the population, the negative impact of human activities on the ecological environment is also increasing, such as overgrazing caused by the rapid increase of livestock.

The photos below show specialized cells of a living organism.
Based on the parts of the cells that can be observed, these cells are most
likely from the
A. skin of frogs
ООО
B. leaves of plants
C. gallbladders of animals
D. roots of plants

Answers

Answer:

B

Explanation:

i am not sure also..sorry

Down syndrome is a genetic disorder that is also called trisomy 21. A person with Down Syndrome has an extra copy of chromosome 21. What can you infer is most likely the genetic mutation that results in Down syndrome?

A: Nondisjunction during meiosis
B: Complete duplication of chromosomes during polyploidy
C: Translocation during genetic replication
D: Crossing over during meiosis

Answers

Answer:

A : Nondisjunction during meiosis

Answer:

Nondisjunction during meiosis, resulting in uneven distribution of chromosomes

Explanation:

I took the test and got it right good luck!

do thyroid hormones influence heart rate from influencing the heart itself, or the attached to it?

Answers

Answer:

An excess of thyroid hormones increases cardiac contractility and resting heart rate (see box below). Cardiac output may increase by 50-300 per cent as a result of the combined effect of increases in resting heart rate, contractility, ejection fraction and blood volume, with a concomitant decrease in SVR.

When there is plenty of oxygen available in the muscles, the condition is referred to as being:

Answers

Answer:

Aerobic condition.

Explanation:

When there is plenty of oxygen available in the muscles, the condition is referred as aerobic condition because the muscles do respiration in the presence of oxygen. The presence of oxygen to the muscles produced huge amount of ATP which can be used by the body in different activities as compared to anaerobic condition where there is no oxygen and the body produce less ATP for the body.

Other Questions
All of the following were true regarding Germany in the aftermath of World War IIEXCEPT:1) Germany was originally divided among 4 Allied Powers.2) The city of Berlin was divided into an East and West Berlin.3) The Soviet Union maintained influence over West Berlin.O 4)West Germany flourished under the influence of capitalism and a democraticgovernment. Use the ideal gas law, PV=nRT to solve. R=0.0821If I have 15 moles of gas at a temperature of 299K and a volume of 92L, what is the pressure of the gas? The frequency distribution below summarizes the home sale prices in the city of Summerhill for the month of June. Determine the lower class limits. If the current through a circuit is 2 A and the resistance of a light bulb in the circuit is 10 Ohms what is tge voltage difference across the light bulb PLZ VERY QUICK The Mystery of Loch NessBy Kayden MitchellOf all the mysteries in the world, none has been as popular as that of the Loch Ness Monster. Perhaps the biggest mystery is whether it is convincing evidence or a simple desire to believe that keeps the myth alive.Loch Ness is a lake in Scotland. The loch, or lake, is known for sightings of a mysterious monster. Most who see this monster, known as Nessie, describe something with a long neck and several humps above the water. Sometimes the "monster" is moving in these sightings, and sometimes it is still. Many have suggested that Nessie might be a plesiosaur (plea-see-a-soar), an aquatic dinosaur that was trapped in the loch after the last ice age.The plesiosaur theory presents several problems. First, the plesiosaur is an air breather. Such a creature would need to surface often and, therefore, be seen more frequently. Second, it's unlikely that the same creature has lived in the loch since the last ice age. Today's creature would have to be the offspring of an original plesiosaur trapped long ago. This would suggest multiple creatures in the loch (needed to produce offspring). Again, sightings would be more frequent if this were the case.So from a purely logical stand point, the existence of such a large and ancient creature is unlikely. But assume for a minute that it is possible. What would a plesiosaur need to live in an enclosed lake?Tropical waters: Scientists believe plesiosaurs were warm-blooded. Like crocodiles and alligators, plesiosaurs would need to live in warm waters. The loch is very cold with temperatures averaging about 40 degrees Fahrenheit (4.4 Celsius).Food: Like other warm-blooded creatures, plesiosaurs would need a large quantity of food. If there is a group of Nessies, then even more food would be needed. Because the loch is full of silt (underwater dust) not much light gets into the deepest areas. So the food chain, which would depend on plankton, is very weak at its base. As a result, there is probably not enough food to support such a large creature.However, the plesiosaur theory is not the only one. Many other ideas attempt to explain the sightings and "photographs." But two separate sonar surveys of the loch have not found any evidence of a creature larger than a salmon. The last survey1, completed in 2007 by the British Broadcasting Company (BBC), involved 600 different sonar beams. Using satellite navigation systems, the team made sure every inch of the loch was searched. The team found nothing.With cell phones and digital cameras, one would think that sightings of Nessie would increase. This has not happened. The BBC team believes the legend of Nessie has endured because people see what they want to see. To prove this, the team used a fence post, raising it before groups of tourists. Afterwards several of the tourists asked to draw pictures of what they had seen drew pictures of a monster's head.1 "BBC 'proves' Nessie does not exist." 27 July, 2003. http://news.bbc.co.uk/2/hi/science/nature/3096839.stmBased on the essay, what makes people think they have seen something in the loch? The many sonar studies have identified strange objects in the water. The myth of the creature makes people imagine they have seen one. The sightings have occurred over a very long period of time. The simple explanations suggest reasons why a creature may have survived. from the following equation in which decomposition of CaCO3 takes place, give your justification. CaCO3 gives Ca +CO2 draper, florist, cobbler are categorized as a) handiwork b) professionalHow many semiquavers make a quaver? How does Powell's use of "I" and "you" support his point in the first half of the speech? Read the excerpts from " The Royal House of Thebes " and " The Story of a Warrior Queen ."Ismene weeping came from the palace to stand with her sister. "I helped do it," she said. But Antigone would not have that. "She had no share in it," she told Creon. And she bade her sister say no more. "Your choice was to live," she said, "mine to die.""The Royal House of Thebes"When the Roman soldiers burst in upon them, they found the great queen dead, with her daughters in her arms.She had poisoned both herself and them, rather than that they should fall again into the hands of the Romans."The Story of a Warrior Queen"Which archetype do the two passages have in common?the warriorthe sagethe villainthe tragic heroine How these changes help you develop and progress as a person or student? Carlos has an aquarium which is 45 cm long, 32 cm wide, and 35 cm high. How much water can the aquarium hold? Can someone help me? Which equation is represented by the table of values below X Y0 31 -12 -53 -94 -13 The most dominant winds flowing poleward out of the subtropical highs in the Northern Hemisphere are: What is the effect on range and maximum height of a projectile as the launch height, launch speed, and launch angle are increased? The 11th term of an arithmetic progression is 14 and the sum of the first 26 terms is 416. Find the first term and the common difference. A company has a website that has seen a large increase in visitors and they are concerned that if the trend continues, the web server's performance will be compromised. You have been asked to help solve this problem without having to replace the current server. What can you do Which sentence best describes a symbol in a story?O A. The dog runs off, along with the character's innocence.B. The writer thoroughly explores the idea of justice.C. Each character must face loss in his or her own way.D. By describing the battlefield, the author sets the mood. Read the text and answer the following questions:1. Kolman shop was once a very rich townTrueFalse2. The UFO buildings are a popular tourist attraction in Taipei.TrueFalse3. Fordlandia became a problem because there was nowhere for the factory workers to live.TrueFalse4. The Ford family sold Fordlandia for $20 million.TrueFalse write a couple of paragraph about your plans after see1 paragraph should have 50 words