Answer:cell.
[Note: This topic focuses on the cell as a system itself (single-celled organism); as a part of larger systems (multicellular organism), and sometimes as part of a multicellular organism. But they are always as part of an ecosystem.]
1. The living conditions is dependent on the structure, function and interrelatedness of cell parts. A living cell is
composed of a small number of elements - - mainly carbon, hydrogen, nitrogen, oxygen, phosphorous and sulfur.
a. because of its small size and four available bonding electrons, carbon can join to other carbon atoms in chains and rings to form large and complex molecules (macromolecules; organic building blocks / amino
acids)
b. the essential functions of cells involve chemical reactions that involve water and carbohydrates, proteins,
lipids and nucleic acids
c. cell functions are regulated; complex interactions among the different kinds of molecules in the cell cause
distinct cycles of activities - - such as growth and division
d. most cells function within a narrow range of temperature and pH; at very low temperatures, reactions are
slow ; high temperatures and/or extremes of pH can irreversibly change the structure of most protein molecules; even small changes in pH can alter how molecules interact.
e. examples of homeostasis at the cellular level to maintain equilibrium are diffusion, osmosis, and active transport
f. cellular organelles include cytoskeleton, Golgi complex, and endoplasmic reticulum
g. every cell is covered by a membrane that controls what can enter and leave the cell
h. within the cell are specialized parts for the transport of materials, energy transformation, protein building,
wasted disposal, information feedback and movement
i. most cells in multicellular organisms perform some specific functions that others do not
2. Scientists believe that prokaryotic cells (in the form of bacteria) were the first life forms on earth
a. from about 4 billion years ago to about 2 billion years ago, only simple, single-celled microorganisms
(Prokaryotic cells) are found in the fossil record
b. oncecellswithnucleidevelopedaboutabillionyearsago,increasinglycomplexmulticellular
(Eukaryotic cells)
c. in all but quite primitive cells, a complex network of proteins provides organization and shape
Step-by-step explanation:
MAKEIN THIS CLEAR IM IN 7th grade trying 2 help but i have all A's