<span>Lipids insulate against the cold.
Fat is our natural coat produced by the over eating process. Not really sure, but it comes to mind that the layer under the skin can be the main reason for it as it prevents and keep our inner parts warm. Also the high blood flow that it demands can help by over circulating it.</span>
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.
The answer would be D. The definition of a homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn't necessarily share the same purpose. The birds and rabbits have similar bones in their forelimbs, but one uses them to run and other uses them to fly.
1. All cells are similar in structure and function.
2. Cell contains hereditary information that is passed from cell to cell during cell division.
3. Living cells can be created from dead cells. All cells perform similar metabolic activities.
hope this helps
<u>Answer:</u>
A mating of two people of medium height (where three genes control height): AaBbCc x AaBbCc produce <u>Seven</u> distinct phenotypes determined by the number of genes inherited.
Option: (D)
<u>Explanation:</u>
- Traits are the characters that we observe. When the parents AaBbCc and AaBbCc are crossed then AABBCC and aabbcc are two different dominant and recessive genomes seen in the offspring.
- Offspring with AABBCC will be height whereas aabbcc will be dwarf. There will be offspring with different heights depending upon the dominant and recessive gene present in them.
- Another genome produced are AABBCc/AaBBCC/AABbCC, next will have four dominant and 2 recessive, next will have 3 dominant and 3 recessive AaBbCc, next will have 2 dominant and 4 recessive, one dominant and five recessive. All together offspring produced will be 64
