Answer:
The correct answer will be option-D
Explanation:
Stem cells are the cells which have the ability to form different types of cells. They differentiate and specializes to perform different functions in the body and thus forms the different cells.
The differentiation and specialization are controlled at the gene level by different patterns of gene expression. The pattern of gene expression is not fully understood during development but research have shown that the gene expression is influenced by the different environmental signals and internal regulators.
Thus, option-D is the correct answer.
Many trees are evergreen so that plants can photosynthesize right away when temperature rise, many trees that have needle-like leaves which shape losses less water and sheds snow more easily than broad leaves waxy coating on needle-like prevent evaporation need-like leaves are dark in color allowing solar heat to absorbed many trees have branches that droop downward to help shed excess snow to keep the branches from breaking.
Methane the most, small amount of oxygen and other gases
