1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ahrayia [7]
2 years ago
7

What is composed of masses of nerve cells, with fibers, running upward and downward;

Biology
1 answer:
sukhopar [10]2 years ago
5 0

Answer:

B. Peripheral nerves

Explanation:

Peripheral nerves use bundles of nerve fibers (axons) to send information around the central nervous system.

You might be interested in
All life on earth exists in a region know as
Fofino [41]
The answer is 'The Biosphere.'
3 0
3 years ago
Which of the following adaptations is most closely related to what the animal eats
ratelena [41]

Answer:

D

Explanation:

4 0
3 years ago
Are viral infections curable? Why or why not?
Anna11 [10]

Answer:

no.

Explanation:

Viruses, on the other hand, are not cellular. We can't kill them simply by disrupting their cells. They are infective nucleic acids which cannot replicate outside of living cells. They must invade a human cell to reproduce, because they cannot produce energy or synthesize molecules on their own. Some viruses replicate inside human cells and then bud off from the human cell inside an "envelope" made from the human cell's own membrane, which helps them evade the immune system on their way to infecting another human cell. Many viruses are protected by protein capsids, which are extremely protective--unlike a bacterial cell wall or membrane, the virus doesn't have to be alive inside the capsid or exchange nutrients and waste with the environment across the capsid; the capsid is merely there to protect the nucleic acid of the virus.

Viruses need to match some sort of receptor in order to gain entry into human cells, and in some viruses, this receptor is one of the few good targets for drug therapy; however, unlike antibacterials, the drug will only work for that particular virus/receptor, because each virus uses a different receptor.

Viruses spend time inside human cells, which protects any outer antigens from some of the aspects of the immune system. There are times when viruses are especially vulnerable during replication, but there are reasons they are harder than bacteria to target with these antireplication drugs: 1) unlike for most bacteria, the drugs need to be small enough to enter the human cell where the virus is replicating, 2) unlike for most bacteria, the drugs can't simply target a protein shared by most viruses; furthermore, many viruses hijack human proteins which cannot be targeted. Overall, there are comparatively few antiviral drugs compared to antibiotics because of the huge difficulty in obtaining selective toxicity. And 3) most drugs available target a certain step of viral replication for a certain family of viruses; however, by the time the patient shows symptoms, the virus has already created countless copies of itself or become latent in human cells, and at that point it is too late for most of the antiviral drugs to be super helpful since they target the replication itself. Even when a good antiviral drug is developed, most of them work only against a single species (or at best, a family) of viruses, which is not the case for most antibiotics.

Many viruses don't spread in ways where they can easily targeted (Polio moves from the GI tract to lymph nodes and then to the blood stream on it's way to the spinal cord to cause paralysis; it is vulnerable to the immune system in vaccinated individuals while it is forced to travel in the blood. In contrast, some viruses like rabies, herpes, and varicella-zoster spread through neurons in order to evade the immune system. Other viruses form syncytia because they travel directly from cell to cell). Also remember that some viruses integrate themselves into human DNA and remain latent for long periods of time, which prevents them from being cleared by drugs or the immune system. The human immune system does have its ways of dealing with viruses, which I can get into in greater detail in another post. For certain viruses, the only way we have to treat them is to use interferons to ramp up the immune system (a very unpleasant therapy which must often be maintained for very long periods of time).

One of the reasons that vaccines for some viruses are not effective is that oftentimes, a live (attenuated) vaccine cannot be made for those certain viruses since the reversion mutation rate is too high to provide an acceptable risk; for many viruses, only killed strains can be used, if at all. Without a live attenuated virus strain multiplying inside cells, certain critical aspects of the immune system are not activated against these certain viruses. In cases where killed viruses are able to be used as vaccines, the protection is lesser (for instance, no type-switching to IgA antibodies which would be more effective than IgM) and shorter-lived.

7 0
3 years ago
Read 2 more answers
A bat species (species 1) lives in a city. Another bat species (species 2) established a population in that same city after some
ddd [48]

Answer:

Roosting areas in buildings of any height are the resource partitioning of both bat species.

Explanation:

  • The <em>fundamental niche</em> refers <u>only </u>to <u>physic conditions</u> in which a species can live and survive in the absence of any interaction with other species.
  • The <em>realized niche</em> refers to the <u>restricted conditions</u> in which a species can live and survive as a result of <u>environment physic characteristics</u> and the <u>interaction</u> with other species.
  • <em>Competitive exclusion</em> refers to the <u>exclusion</u> of the inferior competitor by the superior competitor when there is not habitat differentiation, and both species can not share the same niche. In this case, the effective niche of the dominant species completely occupies the fundamental niche of the inferior competitor.
  • Resources partitioning refers to one dominant species monopolizing the resources, and the other inferior species use resources -partially or completely-, migrates or get extinguished.

A way in which species can divide resources is by living in different habitat areas. These species <em>might eat the same food</em>, and <em>can roost in different places</em> within the same habitat. This resource partitioning and differentiation in the function of their physic location allows both species to coexist more effectively.

In the present example, both bat species can coexist in the same city but the weaker bat species (species 1) roost at the top of the shorter buildings while dominant species (species 2) roost at the top of the highest buildings.

5 0
2 years ago
_______ reinforcers have innate reinforcing qualities. classical operant primary secondary
Liula [17]
Primary reinforcers have distinctive reinforcing qualities; not learned. In addition, secondary reinforcers has no inherent value and only has reinforcing qualities when linked with a primary reinforcers. The positive reinforcement is a desirable stimulus is added to increase behavior while negative reinforcement is an undesirable stimulus is removed to increase behavior.
5 0
3 years ago
Other questions:
  • The growth potential of healthy people was emphasized by
    10·1 answer
  • The level of organization when different primary tissues are combined together and work together to perform a common function is
    8·1 answer
  • Which asteroid is the greatest distance from the sun and why?
    6·1 answer
  • What happens in meiosis during telophase 2
    10·2 answers
  • Which key morphological feature is used to classify organisims as mammals?
    15·1 answer
  • Which of the following is not a function of astrocytes?
    5·1 answer
  • In pointers dogs, the Punnett square for tail length is below (gene A). Use the Punnett Square below to determine the possible o
    10·1 answer
  • sorry for a grainy picture. please help, and please don’t answer something random just for points, this is due in 30 mins
    14·1 answer
  • Organisms that can produce their oven food and feed themselves are called
    15·1 answer
  • Please help urgent due today
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!