Human skin cells, blood cells, and immune cells all contain the same number of chromosomes and the same sequence of genes. What allows them to each perform such different specialized functions?

1.Random mutations occur as cells grow and divide which changes their function

2.The ability to erase certain sections of their genes

3.The ability to rewrite their DNA sequence as they grow and change

4.The ability to regulate gene expression within each different type of cell

The correct answer is option 4, The ability to regulate gene expression within each different type of cell

Explanation:

Although many types of cells have the same DNA codes, the gene expression of each type differs, allowing for them to appear different from one another.

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

explanation:

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.