A. they arose out of Africa less than 200,00 years ago
Answer:
Germline mutations
Explanation:
Mutation in the cancer critical genes leads to the formation of stable mutant protein whose accumulation leads to the origin of cancer cells. Mutant p53 proteins not only lose their tumor suppressive activities (P53 gene is a tumor suppressive gene) but often gain additional oncogenic functions that allow for uncontrolled division of cells allowing increased growth and survival advantages. the same also goes for the retinoblastoma gene which is also a tumor suppressor gene that regulates cell division and other cellular activities. This mutations are usually inherited and can be transfered to their offspring.
Answer:
A. chromosome
Explanation:
Chromosomes are typically what you see in a chart like karyotype that shows all the chromosomes of a particular organism. These are the highly condensed structures of DNA during replication which makes it easy to transfer DNA during replication.
Answer:
sulfur oxide and nitrogen oxide
Explanation:
these are released from power plants along with carbon dioxide
Answer:
CD4 on the surface of helper T-cells.
Explanation:
MHC class II ( major histocompatibility complex) molecules are processed from the exogenous source. The presentation of antigen on cells are important for the adaptive immune response.
MHC class II interact with CD 4 present on the surface of T helper cells. This interaction is important for the generation of an immune response. Helper T cells can release cytokines and can perform phagocytosis.
Thus, the correct answer is option (C).
