Answer:
In a hypotonic solution, the solute concentration is lower than inside the cell. If the water continues to move into the cell, it can stretch the cell membrane to the point the cell bursts and dies.
Explanation:
Answer:
DNA may be taken up by bacterial cells and be active.
Explanation:
To understand Avery, MacLeod, and McCarty's experiment, it is important to know Frederick Griffith's precursor experiment. The microbiologist worked at the British Ministry of Health's Pathology Laboratory with pneumococci (commonly known as the bacterium Streptococcus pneumoniae, then known as Pneumococcus, which causes pneumonia), which were previously classified into several types. When cultured in petri dishes in the laboratory, the pneumococci that synthesize their capsules generate 'smooth' colonies. Subcutaneous injection of liquid culture of these pneumococci into mice causes their death. However, in vitro culture also allows the emergence of rough colonies', whose bacteria have lost the ability to synthesize mucopolysaccharide (and therefore have no capsules). Rough mutants could no longer be classified with sera and, moreover, lost their virulence: mice inoculated with them remained alive, unlike inoculated with smooth pneumococci.
The nature of Griffith's transforming principle remained unclear until the work of Avery, MacLeod, and McCarty. They repeated the in vitro transformation of pneumococci at the Rockfeller Institute for Medical Research, but replaced heat-dead cells with a purified fraction of smooth bacterial extract (unable to cause disease alone) and treated the material with different enzymes, each capable of destroying a specific type of macromolecule. Experience has shown that this fraction retained its transforming capacity when treated with protein or RNA degrading enzymes, but lost that ability when treated with DNA degrading enzymes. These results indicated that the chemical nature of the 'transforming principle' was DNA.
Thus, we can conclude that in addition to identifying genetic material, Avery, MacLeod and McCarty experiments with different strains of Streptococcus pneumoniae demonstrated that DNA can be absorbed by bacterial cells and be active.
The correct answer is: c.)Bilaterally symmetric animals can be streamlined for swimming, but radially symmetric animals cannot.
In radial symmetry the body can be divided by several cutting planes that produce roughly identical pieces. Organisms with such symmetry are usually cylinder, with no left or right sides only top and a bottom surface. Radial symmetric organisms are symmetrical about an axis that goes from the center of the oral (top) surface, to the center of the opposite (bottom) end. It is suitable for sessile animals or slow moving animals.
In bilateral symmetry one plane can divide an organism into roughly mirror image halves (the right and left halves). One of the advantages of the organisms with bilateral symmetry is the streamlining of the body.
Answer: A
Explanation:
The answer is A on quiz and right