The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
When ten or more pre-synaptic neurons conduct impulses to five or fewer post-synaptic neurons, the conduction pattern is said to be <u>convergent</u>.
A neuron in such a network can take information from numerous other neurons through convergence. Inhibitory interneurons are activated by presynaptic cells, but instead they reduce nearby cells inside the network.
Synaptic divergence refers to the dispersion of synapses from such a single neuron onto several postsynaptic partners as well as partner kinds, while synaptic convergence refers to being affected by having neuronal cell kinds delivering input around on a shared postsynaptic partner.
Multiple presynaptic cells send convergent information to a single postsynaptic neuron.
To learn more about neurons, here
brainly.com/question/10877140
#SPJ4
Answer: Option (d) is the correct answer.
Explanation:
Nucleus of an atom consists of protons and neutrons. Protons are positively charged and neutrons have no charge. So, due to the like charges of protons there occurs electrostatic force of repulsion inside the nucleus of the atom.
But due to similar number of neutrons and protons a force that is able to bind both of them together is known as strong nuclear binding energy.
This force is strong enough that it is able to overcome electrostatic force of repulsion. But when there is great difference in the number of protons and neutrons then binding force is not strong enough.
Hence, the atom becomes unstable and undergoes radioactive decay. So, this means weak forces are responsible for radioactive decay.
Thus, we can conclude that the statement which best describes Yanni’s error is that the strong force is responsible for radioactive decay.
Answer: the correct answer is E. Snakes, a major predator of young prairie voles, are active only from spring through early autumn.
Explanation:
Mortality among young voles from spring to early fall is high because snakes are active during this time.
A community refers to the total number of populations that inhabit a
specific location or area. This is part of the levels of organization of life. Arranged from the least complex to most
complex it falls 8th in the category. Below are the organization of life:<span>
a. Organelles - the basic part of a living
organism. It refers to the different structures of the cell, whether
prokaryotic or eukaryotic. (Ex. Mitochondria, nucleus)
b. Cells - building blocks of life that are
composed of different molecules responsible for the function of an organism.
(Example: prokaryotic, eukaryotic cells)
c. Tissues - combinations of cells that carry
out a specific function in an organism. (Example: Human skin)
d. Organs - collections of tissues that perform
specific functions. (Ex. heart, lungs)
e. Organ Systems - composed of interconnected
organs that function as a whole. Many organisms, particularly mamamals, are
composed of organ systems. (Ex. respiratory, circulatory systems)
f. Organisms – individual entities that
specifically make-up a population. (Ex. Each tree in the forest is an organism,
each animal in sea is an organism)</span>
g. Population – species living within a specific location. It could be
the same or different species that inhabit a place. (Ex. Birds are species in
the forest as well as bears)
h. Community – refers to the total number of populations that inhabit a
specific location. (Ex. All of the trees, insects, birds that inhabit the
forest are a community)
i. Ecosystem – consists of all living things that function together as a
group which also includes the non-living parts of the environment. (Ex. Rain
water, nitrogen in the soil)
<span>j. Biosphere – the highest organization of life that consist of all the
collection of ecosystems in the planet. It includes the land, air, water, even
the atmosphere of the planet. </span>
