Internal or external factors can trigger the activation of genes in a cell by --
In the diagram below, a single fertilized salamander egg develops into a salamander embryo (baby).
Student 1 claims all of the cells of the salamander have the same DNA, while Student 2 says all of the cells of the salamander have different DNA.
Which student is correct and why?
is correct because .
In an experiment, scientists expose developing frog embryos to different temperatures. They find that embryos kept at a cooler temperature develop into males, while those at a warmer temperature develop into females.
How does temperature impact the developing frog embryos?
Researchers expose a developing turtle embryo to low levels of a chemical pollutant.
They observe that the affected cells show abnormal patterns of differentiation, leading to deformed tissues. Embryos not exposed to the pollutant develop normally.
Which of these best explains why embryos exposed to chemical pollutants do not form properly?
A group of human cells is exposed to a virus that integrates its genetic material into the host cells' DNA. As a result, the infected cells show altered (changed) gene expression, leading to unexpected differentiation patterns compared to uninfected cells.
How do viruses affect infected cells?
In an experiment, a group of developing cells is exposed to different concentrations of a hormone. The cells exposed to a higher concentration start to form liver tissue, while those exposed to a lower concentration become skin cells.
Which of these best explains how hormones contribute to cell differentiation?
A researcher is studying genetic factors in the development of nerve cells. He finds that when a certain gene is turned off, the cells fail to develop into functional nerve cells and instead remain undifferentiated.
Which of these best explains why the cells did not develop into functional nerve cells?
When a stem cell divides, it produces two daughter cells. One daughter cell will remain a stem cell, while the other daughter cell will differentiate into a specialized cell.
Which factor will most likely determine what type of specialized cell will be produced?
