Stem cells are undifferentiated cells that could develop to perform a variety of tasks. One type of stem cell is the embrionic stem cell. There are also adult stem cells. To use embrionic stem cell you need to have fertilized embrios. These can be donated to research. The use of the embrionic stem cells is controversial for this reason.
Answer:
Infectious dose refers to the minimum number or amount of pathogens required in order to produce a disease or its symptoms. In the given case, the bacterium is non-resistant and is treated with antibiotics.
The antibiotics help in neutralizing the infectious agents; however, full course should be done to eliminate the infectious agent completely out of the body.
If the course is left in between then, there are very high chances that some bacteria may survive. They might not produce disease or symptoms as they would be less than infectious dose.
However, with time, the survived bacteria gain more and more mutations during replication which can develop antibiotic resistance capability in them.
In addition, it is also possible that the survived bacteria can get R-plasmid (which has antibiotic resistant gene) from body's normal flora or from any other infectious agent present in the body by the process of transformation or conjugation.
The R-plasmid enables them to survive even in the presence of antibiotics due to which the treatment of the disease might become difficult.
Answer:
D) observation that certain tumor-suppressor genes and oncogenes are involved in a sequential manner in the development of colon cancer
Explanation:
Cancer is defined as the abnormal growth of cells of the body. These cells multiply/replicate without control thereby forming a lump or tumor.
Cancer growth has 5 stages and they go though different multi level steps.Different finding backs this up and it includes observation about certain tumor-suppressor genes and oncogenes being involved in a sequential manner in the development of colon cancer.
Answer:
If you have anyone of these answer choices..Its D.All of the Above
Explanation:
A. Cells are the structures that contain all of the materials necessary for life
B. Cells are found in all organisms
C. Cells are sometimes specialized for particular functions
D. All of the above
