Answer:
Plant cells have a cell wall, as well as a cell membrane.
Explanation:
In plants, the cell wall surrounds a cell membrane. This gives the plant cell its unique or rectangular shape. animal cells simply have a cell membrane, but no cell wall.
The first top one is right
Answer:
(B) calmodulin
Explanation:
Calcium in cells acts as second messenger molecule which regulates the very important physiological and cellular process of cell-like neurotransmission, cell migration, secretion, fertilization and many others.
Calcium acts as a messenger by binding to a calcium-binding protein called calmodulin. Calmodulin forms complex with 4 calcium ions through the side amino acids present in the structure of calmodulin.
Thus, calmodulin is the correct answer.
D. the floodplain shrinks