Testable, possible explanation for a scientific problem
Answer:
Photosynthesis is the process by which plants and other things make food.It is an endothermic (takes in heat) process.Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy.
Explanation:(what happens in this process)
-Sunlight energy is converted into chemical energy by using chlorophyll.Gives plants their green color to the plants.
- Chlorophyll absorbs red and blue light and uses the energy to convert water and carbon dioxide into glucose.
- Plants convert sugar and energy from water, air and sunlight into energy to grow
- formula for photosynthesis : 6CO2 + 6H20 + (energy) → C6H12O6 + 6O2 Carbon dioxide + water + energy
-formation of carbohydrates from carbon dioxide and a source of hydrogen in the chlorophyll-containing cells (as of green plants) exposed to light.
- Plants, algae, and a group of bacteria called cyanobacteria are the only organisms capable of performing photosynthesis .
- plants breath in carbon dioxide and breath out oxygen.
D....................................................
Answer:
the polymerase chain reaction (PCR)
recombinant DNA
plasmids
genetic markers
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.
