Question

why cell wall is not present in animals.what is nucleus .what are the use of it .

Answer 1

cell wall is not preasent in animals because animals can be decreased or increased our body temperature by moving and go to a cool place but plants cannot do this so cell wall protect them from moisture and temperature.The brain of the cell called nucleus.The uses of it is (1) it is very helpfull for increase body temperature by the respiration process.
(2) It control the cell movements.
(3) Cell structure is depend from it.