In cell culture experiments, purified B cells expressing IgM can be induced to switch to producing IgE by stimulating them with an antibody to CD40 (a stimulatory antibody) plus the cytokine IL-4. In an individual undergoing an immune response, these signals would normally be provided by:

Answers

Answer 1

Answer:

TFH cells in the germinal center

Explanation:

The Tfh cells, present in the germinal center, are responsible for maturing and stimulating the class change of immunoglobulins (such as the change from IgM to IgE). This change could stimulate the new classes of immunoglobulins to act with stimulating antibodies to produce an immune response.

It is important to point out that the germinal center is the activated point of a lymphoid follicle that contains B and T lymphocytes, which act in the memory of the cells of the immune system.


Related Questions

When glucose is unavailable, the liver begins to break down fatty acids to supply the rest of the body with metabolic fuel. Explain why fatty acid-derived acetyl-CoA is not catabolized by the citric acid cycle but is instead diverted to ketogenesis when no glucose is available.

Answers

Answer:

Fatty acid degradation produces acetyl-CoA

When carbohydrate concentrations drop, any available oxaloacetate is diverted to gluconeogenesis to produce the glucose necessary for red blood cell and brain function. If acetyl-CoA cannot enter the citric acid cycle (and acetyl-CoA cannot be converted to pyruvate in mammals), it is converted to ketone bodies.

PLS HELP ASAP 4 EXAM Which field of biology has caused
some ethical concerns?
A. biotechnology
B. ecology
C. molecular biology
D. evolution of disease

Answers

Answer:

D. evolution of disease

Explanation:

Biotechnology's growth and regulation has sparked debate in a variety of academic disciplines, including economics, law, politics, and even history. The genetic engineering of living cells, plants, animals, and humans, in particular, has raised ethical concerns.

OAmalOHopeO

the personality of an individual involves his or her​

Answers

Answer:

both

Explanation:

depends on the person's personality I guess or how they act n all

11. Choose the best answer.
A spore is a reproductive structure that contains a haploid cell and
a food supply
a style
a protective coating
a diploid cell

Answers

a protective coating. spores do not have stored food supplies, they are a haploid cell

If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

Answers

Answer:

binary fission

Explanation:

Binary fission is the main type of reproduction of prokaryotic organisms. In binary fission, the prokaryotic cell first duplicates its DNA and then divides into two cells, each one receiving one complete DNA molecule. Since binary fission is a type of asexual reproduction, this process increases the prevalence of beneficial mutations in a bacterial population. Moreover, transduction refers to the process by which a virus transfers genetic information from one bacterium to another bacterium. Conjugation is also a sexual mode of transfer of DNA from a donor (F+) to a recipient (F−) bacterial cell by direct cell-to-cell contact. Finally, transformation refers to the transfer of genetic material by which bacteria take up exogenous DNA from the environment and integrate it in their genomes.

Match the following: 1. the continuous movement of water between the Earth's surface and the atmosphere lead 2. pollutes water sources by dumping wastes in rivers, streams, and oceans putrefaction 3. the leading cause of water contamination in countries without water treatment plants stimulants 4. a source of water pollution caused by the overuse of pesticides and fertilizers humoral immunity 5. caused by an overabundance of organic matter in water supplies agriculture 6. the decomposition of organic matter by microorganisms hydrological cycle 7. a chemical pollutant that can enter the water cycle through agricultural or domestic use bacterial infection 8. can cause the contamination of underground water supplies if poured on the ground industry 9. a metal that leaks into water supplies via the soil or aging water systems eutrophication 10. depends upon the production of disease-specific antibodies to destroy harmful bacteria sewage 11. increases the activity of the central nervous system petroleum 12. reduces the activity of the central nervous system pesticides 13. caused by the reproduction of a small infectious agent, which produces poisons that destroy cells depressants

Answers

Answer:

Explanation:

1. Hydrological cycle: the continuous movement of water between the Earth's surface and the atmosphere.

2. Industry: pollutes water sources by dumping wastes in rivers, streams, and oceans.

3. Sewage: the leading cause of water contamination in countries without water treatment plants.

4. Agriculture: a source of water pollution caused by the overuse of pesticides and fertilizers.

5. Eutrophication: caused by an overabundance of organic matter in water supplies.

6. Putrefaction: the decomposition of organic matter by microorganisms

7. Pesticides: a chemical pollutant that can enter the water cycle through agricultural or domestic use.

8. Petroleum: can cause the contamination of underground water supplies if poured on the ground

9. Lead: a metal that leaks into water supplies via the soil or aging water systems.

10. Humoral immunity: depends upon the production of disease-specific antibodies to destroy harmful bacteria.

11. Stimulants: increases the activity of the central nervous system.

12. Depressants: reduces the activity of the central nervous system.

13. Bacterial infection: caused by the reproduction of a small infectious agent, which produces poisons that destroy cells

What are some reasons why the control of insect pests is difficult?

Answers

Explanation:

some pesticides make them reproduce faster

During starch test why is leaf boiled in ethanol?
A) to kill its Protoplasm
B) to soften it
C) to extract its chlorophyll
D) to retain its starch

Answers

Answer:

think its C cause when you boil it almost loses all its colour

what do you mean by components of mixture?​

Answers

Answer:

The components of a mixture are the items that are mixed together.

During Meselson and Stahl’s experiment, E. coli was grown on heavy nitrogen for what purpose?
A. So each generation of DNA would have a different weight to distinguish them by.
B. To determine how the bacteria functioned with a heavier element.
C. To see how the heavy nitrogen affected their DNA.
D. So each generation of protein would have a different weight to distinguish them by.

Answers

Answer:

D. So each generation of DNA would have a different weight to distinguish them by.

I took the test

Meselson and Stahl performed an experiment to find out the semiconservative property of DNA and to differentiate the DNA weight of alternative generation both scientists used heavy nitrogen. Thus option A is correct.

What is the semiconservative property of DNA?

When a double-stranded DNA undergoes replication, it results in the formation of 2 double-stranded DNAs and each newly formed DNA has one parental DNA strand and one new DNA strand and this is the semiconservative property of DNA.

Heavy nitrogen of media will appear in the newly synthesized DNA strand so each generation of DNA would have a different weight . So option A is correct.

Learn more about Meselson and Stahl experiment, here:

https://brainly.com/question/15764610

#SPJ5

A scientist makes a discovery that suggests a hominid species created and used relatively sophisticated tools. The scientist decided to publish his findings. Which of the following sources would be regarded as the most reliable?

Answers

a journal reviewed by peers

Answer: The answer is A Journal Reviewed By Peers

Explanation:

what is the average lifespan of a sperm cell​

Answers

[tex]Hello[/tex] [tex]There![/tex]

The answer is...

5 days at least.

Good luck!

[tex]AnimeVines[/tex]

Explanation:

the answer is up to 5 days

Each chromosome is like a package that contains numerous _____. Dna molecules. Traits. Genes. Cells. Help needed ASAP

Answers

Answer:

Each chromosome is like a package that contains numerous genes.

I hope this helps

Which of the following structures contain the highest conc of RNA..
A) Centriole B) Lysosome
C) Chromosome D) Nucleolus

Answers

Answer:

D.) Nucleus

Explanation:

The Nucleus structure contains the highest conc of RNA..

Hope it is helpful to you

Type your answer here.
Organ/Structure
Role in Nervous System
Are the cells that make up the nervous
system. They have three main parts—a
cell body, dendrites, and an axon. These
cells form networks and communicate
with each other via a type of chain
reaction.
central nervous system
Consists of all the nerves of the body. The
nerves take information and deliver
messages to and from this system
brain
Gets messages from the PNS to the brain
and directs messages from the brain to
the intended destinations along the proper
nerve pathways.
(Score for Question 2: of 5 points)
2. Distinguish between autotrophs and heterotrophs. Provide one example of each.

Answers

Autotrophs can produce their own food. Heterotrophs rely on autotrophs for food.

Explain the characteristics scientists use when observing organisms and placing them in the six kingdoms .

Answers

Archaebacteria. Archaebacteria are the most recent addition to the kingdoms of organisms.
Eubacteria. Eubacteria are also single-celled bacterial organisms.
Fungi. The Fungi kingdom is recognizable to us as mushrooms, molds, mildews and yeasts.
Protista.
Plants.
Animals.

Skeletal muscle is controlled by the organism.

Which best describes what this means in terms of movement?

Answers

Answer:

Voluntary

Explanation:

Because some of the muscle attached to the skeleton is voluntary

Which Statement isna conclusion?

A. It's better to give people balloons than cut flowers that will die.?

B. Florist Put cut flowers in sugar water, so flowers in sugar water stay fresh longer?

C. How can cut flowers stay fresh for a longer period of time?

D. cut flowers placed in sugar water fresh longer than flowers placed in regular water.​

Answers

Answer: C

Explanation:

Consider the formula for glucose C6H 1206 .in the process of photosynthesis what supplies the hydrogen used in the formation of glucose

Answers

Answer:

Explanation:

H2o

Explain two ways in which mitosis is biological significant​

Answers

Mitosis is a way of making more cells that are genetically the same as the parent cell. It plays an important part in the development of embryos, and it is important for the growth and development of our bodies as well. Mitosis produces new cells, and replaces cells that are old, lost or damaged.

Please mark me as the brainliest

Which radioactive isotope would you use to date a 4-billion-year-old piece of granite?

A . Carbon - 14 dating
B . Uranium- 238 - lead 206 dating
C .potassium - argon dating

Answers

Explanation:

Uranium- 238 - lead 206 dating

What is the study of tissue? ​

Answers

The answer is:

The study of tissue is known as histology. To go more in depth, the study of the disease of tissues is known as histopathology.

One moth population carries three alleles at a genetic locus: X1, X2and X3. X1is dominant to X2and X3; X1produces red antennae. X2is co-dominant to X3; X2X2produces yellow antennae, X3X3produces white antennae, and X2X3produces light yellow antennae. The phenotypes in a population are as follows: 0.04 white; 0.16 light yellow; 0.16 yellow; 0.64 red.Assuming that this population is in Hardy-Weinberg equilibrium, what is the frequency of the X3allele in this population

Answers

Answer:

The correct answer is - 0.20

Explanation:

According to Hardy Weinberg equation under specific conditions the frequencies of the allele in the gene in a given population remain constant. Thus according to this frequencies of allele and genotype will remain the same through the generation unless there will be no evolutionary influence.

It helps us to predict the genotype frequencies in a large population.  If there are two alleles having allelic frequencies p and q and we know equation of probability and frequencies add to 1

p2+2pq+q2=1

The X3X3 genome produces white antennae. Now Phenotypic frequency of the white antennae is 0.16 or 0.04 in the whole population. Hence the frequency of X3 should be a square root of 0.04 i.e, 0.20.

Anthropologist have a keen interests in honey bees .why?

Answers

Answer:

But extrapolate to all the bees in a beehive and that singular moment is multiplied tens of thousands of times. ... The honey bee and flowering plants represent one of the most successful examples of mutualism in nature. Our food chain depends very heavily on the role of the bee as it pollinates.

Which plant is use for pine I am just in grade 5

Answers

Answer:

Pine may also refer to the lumber derived from pine trees

pine is one of the more extensively used types of wood used as lumber.

Explanation:

The Channel Islands are a series of small islands off the California coast. Each island has a genetically distinct population of foxes. Compare the population of foxes on one of these islands to the population of foxes in the forests of mainland California. Which is more likely to be impacted by genetic drift? Which is more likely to be at Hardy-Weinberg equilibrium?

Answers

Answer:

The fox population on the Islands experiences genetic drift  whereas foxes in the forests has Hardy-Weinberg equilibrium.

Explanation:

The fox population on the Islands experiences genetic drift because there is no chance of introduction of different type of foxes in these Islands which experiences less variation in the population of already existing foxes. Genetic drift is the change that occur in the frequency of an existing gene allele in a population due to random sampling of organisms. Genetic drift may cause gene variants to disappear completely with the passage of time which leads to reduce genetic variation. The foxes that is located in the mainland forest experiences Hardy-Weinberg equilibrium.

The cell membrane regulates what enters and leaves the cell, only allowing
certain things to enter or exit. This is called:
A:Selective Permability
B:Homeostasis
C:Osmosis
D:Transport

Answers

Answer:

A)selective permeability

Explanation:

it allows for it to choose ,small particles easily enter and leave the cell unlike large particles

Your answer would be selective permability

Identify the four key concepts of Darwin's theory of natural selection. (2 marks)
Explain how Lamarck's theory was different and why it got rejected over time. (2 marks)

Answers

The answer above me is correct

An important species of an Atlantic ocean community is the giant kelp, which helps form a suitable habitat for
fish and marine invertebrates.
Which of the following best describes the role of giant kelp in its ecosystem?
Choose 1 answer:
A dominant species
A pioneer species
A foundation species
An invasive species

Answers

Answer:

The giant kelp is a foundation species in its ecosystem.

Explanation:

The kelp acts as a home to the fish and the marine invertebrates, so they can be best described as a foundation species, or species that make an ecosystem suitable for a group of other species.

Answer:

from khan academy :)

8. How is penicillin used?
O to make cheese
O to kill protists that cause disease
O to kill bacteria that cause disease
O to make bread rise

Answers

Answer:

O to kill bacteria that cause disease

Explanation:

penicillins are a group of antibiotics used to treat a number of bacterial infections.

hope this helps!

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