In biological systems, there are several membrane transport systems responsible for the passage of ions like Na+ and K+ , or small molecules like glucose and amino acids, through biological membranes. Classify each membrane transport system as either a primary active transporter, a secondary active transporter, or a passive transporter. Which transport systems utilize a chemical reaction for the energy source?

Answered below

Explanation:

Cell membranes are barriers which protect and regulate the movement of substances in and out of the cells. It is a semi-permeable and selective structure.

In the passive transport system, substances move along a concentration gradient and it doesn't require energy. The examples of passive transports include; simple diffusion which transports carbon dioxide and oxygen, osmosis and facilitated diffusion which transports charged molecules like ions, sucrose etc.

In active transport, substances move against the concentration gradient. This requires energy. The two main types are: primary active transport, which uses direct metabolic energy e.g Na+/K+ pump, and the secondary active transport system which couples the transported molecules with another molecule moving along the gradient, example the Na+/glucose transporter.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.