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.
Solar energy from the sun.
Geothermal energy from heat inside the earth.
Wind energy.
Biomass from plants.
Hydropower from flowing water.
DNA carries the "codes" that communicate what traits will be formed. The nucleotides in DNA are read and transcribed into mRNA which travels ot of the cells nucleus and then goes to a ribosome. In the ribosome, tRNA matches to mRNA with its anticodon. Each of the tRNA molecules are carrying an amino acid which are all connected by the ribosome to create an amino acid chain, which is a protein, which are traits in an organisms.
Answer:
75%
Explanation:
3/4 of the phenotype will have O blood group, and 1/4 will have A blood group.
Answer:
Evolution.
Explanation:
The ground finch could not survive after the drought with the size of its beak.
The beak required in order to feed on the hard seeds needed to be stronger and longer.
Due to this, the finch beak <em>evolved and developed into a stronger longer beak</em> adapted to feeding on large hard seeds.
Without this evolution, all the finches left on the Galapagos island could face <em>extinction out of starvation.</em>
