Answer:
Enzymes are proteins that act as biological catalysts. Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products.
Explanation:
Hope this helps
Answer:
The independent variable is "controlled" or held constant in the control group.
Explanation:
I would say A. Mainly because the teacher is well trained for situation where it's critical or something like that..
2: most energy plants in the U.S. use coal as its fuel
Answer:
Option). NK cells.
Explanation:
Cluster of differentiation 8 (CD8) can bed defined as a transmembrane glycoprotein that acts a co-receptor for the receptor present on T cells (TCR). The CD8 is marker for 
cells (cytotoxic T cells) as it is predominantly present on cell surface of these cells.
Along with cytotoxic cells, CD8 molecule is also expressed in surface of natural killer cells (NK cells), thymocytes, and myeloid dendritic cells.
Hence, a cell having CD8 on its surface (cytotoxic T cell) would be most similar to NK cells.
