1- why dong you usually get sick from the exact same pathogen twice

2-if a pathogen mutated so it had different antigens, would your memory B and memory T cells recognize it?

please help this is due at 3pm

Answers

Answer 1

1: For example, rhinovirus has over 100 different serotypes. Now, the good news is that you can't get ill from the same virus serotype right after getting better, due to the fact that you'll have developed antibodies which help to protect your immune system for a little while.

2:Most children in the United States are now vaccinated against measles virus; before vaccination was widespread, most were naturally exposed to this virus and suffered from an acute, unpleasant, and potentially dangerous viral illness. Whether through vaccination or infection, children exposed to the virus acquire long-term protection from measles. The same is true of many other acute infectious diseases: this state of protection is a consequence of immunological memory.

The basis of immunological memory has been hard to explore experimentally. Although the phenomenon was first recorded by the ancient Greeks and has been exploited routinely in vaccination programs for over 200 years, it is just now becoming clear that memory reflects a persistent population of specialized memory cells that is independent of the continued persistence of the original antigen that induced them. This mechanism of maintaining memory is consistent with the finding that only individuals who were themselves previously exposed to a given infectious agent are immune, and that memory is not dependent on repeated exposure to infection as a result of contacts with other infected individuals. This was established by observations made on remote island populations, where a virus such as measles can cause an epidemic, infecting all people living on the island at that time, after which the virus disappears for many years. On reintroduction from outside the island, the virus does not affect the original population but causes disease in those people born since the first epidemic. This means that immunological memory need not be maintained by repeated exposure to infectious virus


Related Questions

Which of the following sequences represent the complementary DNA sequence to the DNA strand — AGATCCGTA —?

a. CTCGAATAT

b.AGTAGGCTA

c.TCTAGGCAT

d.TCATGGCAT

Answers

Answer :TCTAGGCAT it’s C

Which of the following occur during interphase? Select all that apply.
cells prepare for cell division
chromosomes divide
cytoplasm divides
cells grow rapidly
chromosomes replicate
DONE

Answers

Answer:

cells prepare for cell division

Explanation:

3. What are 6 things the ocean provides for humans?

4. What are three conditions of the ocean that might make it a dangerous place for humans to explore?

Answers

Answer:

What are 6 things the ocean provides for humans?

The Ocean produces more oxygen than the Amazones.

The Ocean regulates the Earth climate.

It is an important source of food.

The best holidays are close to the water.

Many jobs are related to sea activities.

The Ocean has therapeutic properties.

Explanation:

It is often thought that rainforests are the primary source of oxygen on the planet, but the truth is that rainforests are only responsible for 28% of the oxygen on earth while oceans are responsible for the 70%. It does not matter how far we live from the sea, from every ten breaths you take seven come from the ocean

In many ways, the sea regulates our climate. It soaks up the heat and transports warm water from the equator to the poles, and cold water from the poles to the tropics.

The ocean is the number one source of protein for more than a billion people. Fish accounts for about 15.7% of the animal protein consumed globally (2).  Although, not everything is fish and seafood.

The ocean is not just home to us ocean lovers, but it is home to the greatest abundance of life on our planet. When you sail across an ocean, you will see dolphins, whales or a turtle popping up to take a breath.

The ocean is a happy-zone! Our temple, our life, our second home, our exhilaration place. It’s where we swim, surf, sail, dive, chillax, and ‘lime’. Family holidays and Sundays often happen on the beach. For sailors, fisherman and islanders, it also is a transport zone.

The FAO estimates (6) on the most recent official statistics indicate that 59.6 million people in the world were engaged in fisheries and aquaculture in 2016. Only at the European Union level, the blue sector represents 3.362.510 of jobs(7), in 9 subsectors: coastal and maritime tourism, Aquaculture, Renewable Energy, Mineral Resources, Biotechnology, Fisheries, Shipbuilding and Ship repair, Offshore Oil and Gas, and Transport. In fact, 90% of the world trade is made by sea

In a chemical analysis of a sample of animal tissue, which element would most likely be found in the smallest quantity?

Answers

Answer:

Iodine

Explanation:

Iodine is needed by animals because the body's metabolic rate is controlled by the action of an iodine hormone, called thyroxine, which is secreted by the thyroid gland in the neck.

If the animal fails to supply enough iodine through food to be able to make a normal amount of this compound, then the thyroid gland enlarges or expands trying to create enough, resulting in a common type of goiter.

5 tips to improve your critical thinking - Samantha Agoos

Watch the Video and make a summary

Ps: They don't let me paste the link lookup what it says above

Answers

Answer:

that one is hard because we did not see the vidoe

Explanation:

The first line of defense involves which structure(s)?
OT-cells
O skin
O blood
OB-cells

Answers

Answer:

skin

Explanation:

The skin is vital for our general health and well-being. In addition to acting as the body's first line of defense against bacteria and viruses, healthy skin also maintains fluid balance and helps regulate body temperature. She is very sensitive, she recognizes the slightest touch as well as pain.

As an outer layer that we can see and touch, the epidermis protects us from toxins, bacteria, and fluid loss. It consists of 5 sublayers of keratinocyte cells. These cells, produced in the deepest inner, basal layer, migrate to the surface of the skin. As they do so, they mature and go through a series of changes.

help meeeeeeeeeeeeeeeee plz

Answers

Answer:

It would most likely be within the mantle. the mantle is in the interior of the earth;. So inner core.

Explanation:

What are the drops of water that form on cool surfaces during the night called?
A. Snow
B. Dew
C. Steam
D. Rain

Answers

Answer:

The correct option is B

Explanation:

Dew is the water droplets found on objects outside of an enclosed/covered area in the morning. Dew occurs as a result of condensation of moisture in the cold atmosphere (at night) which is converted to liquid when it touches objects of higher thermal energy; converting the water in the moist air into water droplets known.

What three things regarding cell organelles are different between plant and animal cells?

Answers

Answer:

Plant cells have a cell wall, but animals cells do not. ...

Plant cells have chloroplasts, but animal cells do not. ...

Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present

4. Do the rocks appear to have been pushed together, pulled apart, or to have slid past each other to make this formation? What type of fault is this? (4 points)

Answers

Answer:

to have slid past each other to make this formation

Explanation:

Helppp please
Which federal agency, formed in 1977, now combines regulation and other aspects of the energy industry that were
previously scattered under several other agencies?

O Occupational Safety and Health Administration

O Mine Safety and Health Administration

OU.S. Energy Information Office

o Department of Energy

Answers

D. Department of Energy (DOE)

Explanation: The DOE has been officially in charge of all aspects of energy since 1977; their activities prior to this were assigned to various different government agencies.

Answer:  The correct answer is Department of Energy (DOE)

Explanation:  This answer has been confirmed correct.

1. what is an organelle?

2. give me an example of an organelle.

3. Which organelle is the "command center" of
the center?

Answers

Answer:

1. a subcellular structure that has a job to do within the cell

2. mitochondria

3. the nucleus

Which of these are true of physical therapists? Check all of the boxes that apply.

All physical therapists can diagnose.

Physical therapists strengthen muscle and improve balance.

Physical therapists do not prescribe medication.

Physical therapists are considered doctors.

Physical therapists are commonly called physiatrists.

Answers

2nd, and the last one

HELP PLEASE I NEED THE ANSWER ASAPPPP

Answers

Answer:

I think that it's A.

Explanation:

It's not D, because A & C contrast each other.

I would say A

Explanation
A keystone species is an organum that that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exists altogether. Any organism, from plants to fungi, may be a keystone species;they are not always the largest or most abundant species in an ecosystem.

Hope this helps.

Which statement BEST states what happens during mitotic anaphase? The chromosomes are duplicated. O Spindle fibers stretch across the cell. O Sister chromatids move to opposite sides of the cell. O Chromosomes and centrioles attach to the plasma membrane.​

Answers

Answer:

Move to the opposite sides of cell

Explanation:

Answer:

Sister chromatids move to opposite sides of the cell.

all you need is in the photo ​

Answers

Answer:

There are seven essential processes in common: movement, respiration, sensitivity, growth, reproduction, excretion and nutrition or MRS GREN.

but i think the answer is D

Explanation:

Ribosomes are the site where
protiens
are produced.
Amino acids are coded for by triplet bases in RNA called
condon
.

Answers

Answer:

That's true

Explanation:

But remember. What is produced actually is not a protein. It is a petide chain which is the first structure of protein.

When the peptide chain reaches its fourth structure ،it csn have its function in body.

Thats a complete protein.

Hope it helps.

To which human body system does the kidney
belong​

Answers

Renal system, in humans, organ system that includes the kidneys

Answer:

Excretory system would be the answer.

hope it helps!

Moving through trophic levels _______.
a.
energy decreases
b.
entropy increases
c.
biomass decreases
d.
all of the above

Answers

Answer:

Levels of energy decreases as it moves through an ecosystem.

hope it helps!

Answer:

D

Explanation:

All of the above

What is the largest change in the energy industry's emissions in Oklahoma from 1995 to 2015?

Answers

Answer:

The largest change in the energy industry's emission in Oklahoma from 1995 to 2015 is the percentage change in the emission of nitrogen oxides with a reduction of 64.69%

Explanation:

The percentage change in emission is given as follows;

[tex]Percentage \ Change = \dfrac{New \ amount - Initial \ amount }{Initial \ amount} \times 100[/tex]

Which gives;

1) For carbon dioxide, we have;

[tex]Percentage \ Change \ in \ emission = \dfrac{41,626,050 - 43,174,445 }{43,174,445} \times 100 = -3.59 \%[/tex]

Therefore, there was a reduction of 3.59% in carbon dioxide emission between 1995 and 2015

2) For sulfur dioxide, we have;

[tex]Percentage \ Change \ in \ emission = \dfrac{60,943 - 114,317}{114,317} \times 100 = -46.69 \%[/tex]

Therefore, there was a reduction of 46.69% in sulfur dioxide emission between 1995 and 2015

3) For nitrogen oxides, we have;

[tex]Percentage \ Change \ in \ emission = \dfrac{29,381 - 83,201}{83,201} \times 100 = -64.69 \%[/tex]

Therefore, there was a reduction of 64.69% in nitrogen oxide emission between 1995 and 2015

Which shows that the largest change in the energy industry's emission in Oklahoma from 1995 to 2015 was the percentage change in the emission of nitrogen oxides.

Answer:Gases that contribute to smog decreased.

Explanation:I just took the test and that was the right answer.

This type of fossil forms from a mold. Small particles of mud, sand, and/or
minerals becomes packed into the open space of the mold in the shape of a
turtle shell and hardens. The result is a fossil that has the same exact shape
as the original turtle shell.

Answers

petrified mold fossil or cast fossil depending on the text that was taught... some questions are dependent on what words that were taught by the teacher...

Scientists cannot use the scientific method to reproduce another scientists experiment True or False

Answers

Answer:

False

Explanation:

One of the proof of a good scientific experiment is the ability to reproduce the steps leading to the results obtained from the experiment.

To proof the validity of the claims of an experiment by other scientists:

Every experiment must be reproduceable by other scientists. This will enable the experiment to be rid of any bias. For the conclusions of an experiment to be validated by other scientists, such experiment should be tested by others. If the results are the same, then the hypothesis can be advanced. If not, the experiment is redesigned or discarded.

Megan examines a liver cell and observes an organelle with many smooth-
sided channels. Which activity would identify this organelle as the Golgi
apparatus?
Digestion of macromolecules and old organelles
Detoxification of poisonous molecules within the cell
Harvesting of energy from organic molecules to make ATP
Processing and packaging of cellular materials prior to export

Answers

Answer:

Processing and packaging of cellular materials prior to export

Explanation:

Our cells contain many different organelles. Every organelle has its own function, just like every organ in our bodies.

The Golgi apparatus is one of these organelles. It can be found in most eukaryotic cells. Its purpose is to transport, modify, and package proteins and lipids before they're delivered to other parts of the body. This is the function the organelle with smooth-sided channels Megan is observing would need to perform in order to be identified as the Golgi apparatus.

PLEASE ANSWER!! The city council of Jacksonville, Montana, is considering turning some of its grassy areas into large ponds. Farmers have argued against this idea because they are concerned that taking away too much of the grassy areas will hurt the sheep. Write a claim to counter the farmers’ argument, using the data above. Make sure to include a rebuttal in your answer.

Answers

Answer:

As the city council of Jacksonville, Montana is thinking of turning grassy areas into large ponds which is not acceptable by the farmers because they are concerned it will affect the sheep population. Farmers are right because grassy areas form a habitat for the sheep population in that area and make a balance between predators and prey.

As we can see the data of the relationship between predators and prey, growth in grassy areas in years maintains a balance of predators and prey where wolfs are not harming many sheep but if grassy areas will be detroyed, it will be easy for wolfs to dominate sheep population.

The normal function of a tumor suppressor gene is A. To promote growth signals B. To cause the cell to move faster through the cell cycle C. To include programmed cell death D. To code proteins that slow or stop the cell cycle

Answers

Answer:

Explanation:

Tumor suppressor genes are genes that code proteins to slow down or stop cell division. This is because if the cells divide uncontrollable, it will lead to cancer and if tumor suppressor gene is activated it will help to slow down or stop uncontrollable cell division. It is also called anti oncogene and it repair DNA mistakes and tell when cells should die.

Earthquakes release seismic waves, which are waves of .... *
soil
energy
soil and energy
soil, energy, and motion

Answers

Answer:

It would be soil, energy,and motion

Explanation:

Because when there is an earthquake the tectonic plates are pushing upward. so that will cause the soil to come up then the energy beneath to make it move it there's also the motion as it shakes.

How can diabetes be controlled?

Answers

Answer:

Diabetes can be controlled with insulin, medication, exercise and other things.

Explanation:

<3 Hopefully this helps! ^^

How carbon is uniquely suited to Form biological macromolecules give 3 reasons why

Answers

Answer:

Carbon atoms have four electrons of valance. This enables them to form strong covalent bonds with multiple materials. Carbon can also join with it, allowing it to form long chains or atomic rings on carbon.

hope it helps!

The aerobic phase of cellular respiration in the mitochondria produces a net of about 28 to 30 ATP molecules. How does this compare to the energy released in glycolysis

Answers

In glycoliyis 2 moles of ATP are produced per mole of glucose. 28-30 is higher than 2. A lot more energy is produced in the aerobic phase.

Two weeks in a row are rainy, cancelling Lizette's weeding sessions. When she gets back out to the garden, the weeds are huge. Lizette peeks
under the leaves of the weeds and observes some struggling radishes and carrots. They are small and yellowish and look unhealthy.
Since it has rained for two weeks, she knows the plants have plenty of water. Which of the following must also be present for the vegetables to grow
and thrive?
A food
B butterthes
C DNA
D cells be

Answers

Answer:

A

Explanation:

Other Questions
Need answer fast. Drag each label to the correct location on the image.Match each account of events with the type of chronology it illustrates.It was a lousy day. I woke up with aheadache. Then I spilled milk all overmy school clothes. All the way to schoolI worried about that bully Bobbyshowing up. When I got there, I couldn'tConcentrate.At 5:00 p.m., we arrived at the site toadminister emergency care, and wefound one severely injured victim. At5:20, Team B loaded that victim intothe ambulance. Meanwhile, at 5:05,Team A declared the other twovictims to be in good health.Several centuries ago BC, Romancivilization began to develop in the landnow called Italy. It grew to become arepublic. It continued to grow andbecame an empire. Foreign invasionsand economic problems led to itsdownfall. It lasted a few centuries AD.Colonists declared themselvesindependent of Britain in 1776. TheEmancipaNn Proclamation freedenslaved people in 1863.Reconstruction ended in 1877.absolute chronologyrelative chronology only Consider the equation 6*e^{0.25t}=9Solve the equation for t. Express the solution as a logarithm in base-e.Approximate the value of t. Round your answer to the nearest thousandth Define hierarchy in your own words. giving brain liest if its in your own words and its right!! Why does malalas father say circumstances have made wise beyond her years? How accurate is the headline "Study Shows Farmers Spend Several Hours Playing Cards Each Day": mostly accurate, partly accurate, or mostly inaccurate? Use evidence from Placard A to explain your answer. two geometric figures that are proportional in size are ____ figures Plzzz help. Giving 20 pts A ratio that compares two quantities measured in different units is known as a ______________________. Simplify (4i) (5i) - The i is the imaginary number for negative 1 Stephen F. Austin was arrested in San Antonio by Mexican forces. A. True B. False Just would like to see what people's opinions are on my art. plz be honest! Analyzing Why did Washington's efforts to gain the peaceful cooperationof Native Americans in the West fail Identify the axis of symmetry and vertex. Match each mode of transmission with an effective method of blocking it.Animal vector?Getting vaccinatedDirect contact?Washing foodIndirect contact?Using insect repellent What is another name for a row on the periodic table?Answer choices : GroupPeriodFamilyTransition Metals Bones in the skull are immovable. They areconnected by which type of joint?diarthrosissynarthrosisamphiarthrosisgliding if you wanted to help viewers visualize a story or situation which medium would you use?drawings or photos on a page or screenwords on a page or screentext read aloudsound effects or music marking brainliest to whoever can help me Solve the Compound Interest Formula for time given:250,000 = 12,000e^.125t Animals have an advantage over plants with the ability to move. What structure does animals not possess that allows us to be mobile?Large central vesicleMitochondriaChloroplastsCell Wall