Which part of a cell directs the cell's activities and holds its DNA? A. Mitochondrion
B. Ribosome
C. Nucleus
D. Cell membrane​

Nucleus is the answer

A micrograph of animal cells, showing the nucleus (stained dark red) of each cell. Known as the cell's “command center,” the nucleus is a large organelle that stores the cell's DNA (deoxyribonucleic 

nucleus is the part of a cell directs the cells Activities and holds it's DNA

when atmosphere interacts with biosphere they focuses on on the sources and sinks of green house gases (ghgs) air pollutants, particular matters, water and energy between the earth's surface and the atmosphere. the biosphere affects the climate. the atmosphere and biosphere are in constant interaction with each other, and all living things rely on gases in the atmosphere for life. organisms such as animals take in oxygen gas form the atmosphere to use in every cell of their body for smooth functioning of daily routine exercises.