Answer:
The nucleus, cell membrane and cytoplasm.
Explanation:
The nucleus, cell membrane and cytoplasm are three elements that cannot be absent in a cell because they are necessary for the survival of the cell. The nucleus controls and regulates the activities happening inside the cell e.g. growth and metabolism etc. Cell membrane acts as a wall to protect the inner part of the cell from the external environment as well as allows nutrients and gases inside and outside the cell. Cytoplasm serves as a medium for the conduction of nutrients and waste from on place to another and also for the medium for organelles in which they floats.
Answer:
D. A cube
Explanation:
Epithelium cells are a type of cell that has a simple cuboidal epithelium that consists of only a single layer of cells that are cube-like or cuboidal in shape. These cells have large, spherical nuclei present in the center. These cells are cube-shaped cells
Answer:
Epinephrine binds to receptors on some smooth muscles (ex: around arterioles) → Ca++ released from ER → intracellular Ca++ up → stimulates contraction. c. Epinephrine binds to receptors on some smooth muscles (ex: around bronchioles) → phosphorylates protein needed for response to Ca++, preventing response.
<span>Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.</span>
Explanation: the movement of organelles and other substances within cells. Endoplasmic reticulum
