Answer:
Cytoskeleton
Explanation:
The cytoskeleton is a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement. Cytoskeleton is made of filamentous proteins, and it provides mechanical support to the cell and its cytoplasmic constituents. All cytoskeletons consist of three major classes of elements that differ in size and in protein composition including microtubules, actin filaments and intermediate filaments.
A- cell membrane
B- nucleus
C- cytoplasm
D- mitochondrion
E- ribosomes
In the atmosphere, as air warms it rises, allowing cooler air to flow in underneath.
Answer:
ok.
Explanation:
The troposphere is the lowest layer of Earth's atmosphere and site of all weather on Earth. The troposphere is bonded on the top by a layer of air called the tropopause, which separates the troposphere from the stratosphere, and on bottom by the surface of the Earth.