Answer:
The topic of whether viruses are dead, or living, organisms, is pretty much up for debate. Given that there are 8 specific characteristics that would categorize an organism as living, or non-living, and seeing as viruses seem to meet some of these characteristics, but not others, scientists are still not able to define that a virus is definitely dead, or alive. All they know for sure is that a virus is an organism that is comprised of genetic material and a capsule that protects that material, that it uses certain mechanisms to infect a host cell to use it for its survival purposes, and that it can adapt to environmental conditions.
First, lets analyze the 8 criteria that science takes into account to suppose an organism is alive or not, and apply it to viruses. The first criteria is organization. In the case of viruses, these organisms are organized enough that they are not just genetic material on the loose; they have protective barriers and mechanisms that will allow the virus not just to identify a host cell, but also penetrate it and use it in its favor. Second, we have that a living organism must be able to reproduce. In the case of viruses there is still uncertainty on this point. Science knows viruses replicate their genetic material with the help of the cell, and then daughter virions are produced, but not all scientists agree that viruses actually reproduce. They certainly multiply. Third, we have that living organisms maintain homeostasis. In this case viruses fail miserably as all they do is literally infect, be replicated and kill their host. They are not capable of controlling their environmental conditions and are totally dependent on their host. Fourth, we have that living things grow. Viruses do not grow at all. Virions are simply exact replicas of their original virus. Next we have the use of energy. Although still not decided, it seems that viruses take advantage of the energy of the host cell, but it is uncertain if they themselves are capable of producing any energy, or using energy without a host. Then we have response to stimuli. Viruses do not respond at all to this. They are simply programmed to infect and replicate, but if they are stimulated, the process of reaction does not change in the least, like it would happen with bacteria or fungi. Living organisms possess genetic material, and on this point is where most scientists disagree on whether viruses are alive or not, because these organisms do have genetic material. Finally, the eighth characteristic of living organisms is that they adapt and evolve. On this point, viruses also get a passing score. They are able to remain dormant, and stable, even if conditions change, and they will adapt perfectly to new conditions as well, becoming active once more.
So in the end, can we say that viruses are alive? Well, if we look it from several of the characteristics of life, then yes, we would have to say so. Viruses have genetic coding, they replicate, they are organized and they adapt. However, they do not respond to stimuli, their only point is to replicate and kill their host, they depend entirely on host cells to be able to carry out their funtion, so in this case, we would definitely say that viruses are not living organisms.
Answer:
Simple cuboidal epithelia are found in areas that stretch.
Explanation:
The simple cuboidal epithelium consists of a single layer of cuboid cells with a centrally located nucleus. The cells of this epithelial tissue are mostly involved in secretion and absorption and therefore, are found in the lining of ovaries, lining of kidney tubules and gland ducts.
Transitional epithelium is like a stratified cuboidal epithelium when not stretched. Its cells become flatter when the tissue is stretched. It has multiple cell layers and elasticity and therefore, is found in the lining of the urinary bladder and parts of ureter and urethra to allow stretching of these organs.
Answer:
Gene flow is the movement of genes from one population to another population.
Explanation:
Selective breeding of dairy cows to produce animals that can live in tropical climates and yield higher volumes of milk. (There is no gene flow in this example because the organisms being breed belong to 1 population)
The carriage of seeds between two separate urban forests by wildlife such as squirrels and rats that travel back and forth between the two. (This could be an example of gene flow because if those seeds germinate, grow and produce flowers their genes could be mixed up during pollination)
cross pollination by migrating honey bees between two geographically separate but genetically identical cotton fields. ( this is clearly an example of gene flow. Bees are transferring genetic material between populations)
the passage of a recessive disease-causing allele from one generation to the next without the physical appearance of disease. (because the genes are moving from one generation to the next one, this implies only no population, so there is no gene flow here)
The introduction of Burmese pythons, with no known predators or compatible mates, into the Florida Everglades. (there is not an exchange between python populations, only a new species is being introduced)
Answer:
Natural gas use to generate electricity has increased efficiencies for business owners.
Explanation:
Among business owners in the remote who have gotten access to electricity through natural gas have expanded their premises. A research done for people living in the country side shows that availability of electricity has also enhanced security.
Most people are now able to venture into businesses that use electricity e.g,. welding
Answer:a
Explanation:
The correct answer is D. Increases levels of greenhouse gases
Explanation:
Fossil fuels include substances such as coal or petroleum that form naturally on Earth and are extracted by humans to be used as fuels. These substances include large amounts of carbon and other substances that are released when they are burned. Due to this, the burning of fossil fuels implies the production of carbon dioxide (CO2) that is an important greenhouse gas. This implies burning fossil fuels releases carbon dioxide that accumulates in the atmosphere and causes radiation from the sun to be trapped (greenhouse effect). Therefore, one effect of burning fossil fuel is that it increases levels of greenhouse gases as a result of the carbon dioxide released.
Explanation:
plant absorbs water through the root by
the osmosis process
concentration of root is more than water
so. a pressure is developed in the wall of root
by the which water goes up and reaches to the
leaf of the plants
Answer:
the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
Explanation:
Basically the sun gives the plants food that the plants make themselves
Explanation:
Chloroplast
It helps plants generate food through photosynthesis process
Answer:
The similarity is that both transduction and conjugation transformation are transfer mechanisms of genetic material between two bacteria. The difference is that in transformation the DNA is incorporated, while in transduction the DNA is transferred.
Explanation:
In transformation, the bacteria absorb DNA molecules dispersed in the medium and are incorporated into the chromatin. This DNA may come, for example, from dead bacteria. This process occurs spontaneously in nature. Scientists have used transformation as a genetic engineering technique to introduce genes of different species into bacterial cells.
In transduction, DNA molecules are transferred from one bacterium to another using viruses as vectors (bacteriophages). These, when assembled within the bacteria, may eventually include pieces of DNA from the host bacteria. By infecting another bacterium, the virus that carries the bacterial DNA transfers it along with yours. If the bacterium survives viral infection, it may include the genes of another bacterium in its genome.
If cells are grown in a medium containing radioactive 32P-labeled phosphate, then NUCLEIC ACIDS will be labeled (Option B).
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