Measuring the volume of an object you are finding the amount of three dimensional space the object occupies
Answer:
Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.
Explanation:
Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.
Answer:
The correct answer will be option-C
Explanation:
The plant absorbs the sunlight to perform photosynthesis which helps produce the sugar molecule used by the plants.
The plants absorb maximum sunlight at two wavelengths that are red and blue wavelength by chlorophyll and other pigments. The efficiency of photosynthesis is also measured maximum at these two active wavelengths called action spectrum.
In the given question, since the efficiency of photosynthesis has been discussed which could be measured with the production of oxygen and consumption of carbon dioxide. The experiment performed by the Engelmann showed that aerobic bacteria got concentrated in the blue and red wavelengths as the output of the photosynthesis were observed maximum.
Thus, the selected option is the correct answer.
They could look for similarities in the DNA or protein structuresof the organisms<span> and similarities in early development</span>
Answer: Land, Water,Urbanization, and smog and acid rain.
Explanation:
Smog and acid rain are produced through similar sources, primarily vehicle and industry emissions. Though both result from human-caused air pollutants, there are chemical distinctions between the two. Though there are regulations in effect to reduce both types of pollution, they remain a threat to both human health and the environment.Smog Causes A combination of three components -- nitrogen oxides, volatile organic compounds (VOCs) and sunlight -- causes smog. Nitrogen dioxide interacts with sunlight to create nitrogen oxide and a free oxygen molecule. This interaction produces ozone, which typically turns back into nitrogen dioxide, and the cycle repeats. The addition of VOCs interrupts the cycle, however. VOCs are produced by various sources, such as paint, cleaning products and refrigerants. The VOCs prevent the breakdown of ozone, allowing it to gather near the surface of the Earth, where even more nitric oxides are produced by vehicle and industry emissions, creating the dense smog seen in large cities such as Los Angeles and Beijing.Smog Hazards The presence of ozone in the form of smog can have several negative health effects. Respiratory systems can be irritated, reducing overall lung function and triggering asthma attacks. Evidence reported by the Environmental Protection Agency also suggests exposure to ozone reduces immune system responses, especially in the lungs. These effects subside over time, but little is known about the long-term effects of repeated exposure. Vegetation also suffers from smog, as plants that take up too much ozone can be damaged in ways such as discoloration and a loss of leaves that cuts photosynthesis efficiency by up to 50 percent.
