CELL DIVISION
CELL DIVISION AND CANCEROUS CELLS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
The nucleus has instructions to turn some genes on and some genes off.
|
|
|
Signals from chemicals in the organism or from the environment determine which genes will be turned on and off.
|
|
|
Genes turn on and off randomly.
|
|
|
The cell has unique DNA that determines what the cell will become.
|
Detailed explanation-1: -Signals from the environment-chemicals, extracellular proteins/hormones/factors, neighboring cells, the physical environment-converge on the cell, typically activating a signaling cascade that leads to gene expression. These specific proteins change the phenotype into that of a more specialized cell.
Detailed explanation-2: -Embryonic cells are provided with signals that indicate their location in the body. These signals turn gene expression on or off in that cell, causing it to differentiate into a cell appropriate to its location.
Detailed explanation-3: -Q. How do stem cells know what type of cells to differentiate into? The nucleus has instructions to turn some genes on and some genes off. Signals from chemicals in the organism or from the environment determine which genes will be turned on and off.
Detailed explanation-4: -Transforming growth factor (TGF)- and WNT signals are involved in human ES cell differentiation into mesendoderm and endoderm, whereas bone morphogenetic protein (BMP), vascular endothelial growth factor, and FGF2 are key regulators of the differentiation of ES cells into mesoderm.