Plant cells have cell walls and animal cells do not because the plant cell needs it for its activities.
Answer:
White blood cells can be called the strong defender of our body from foreign substances. These cells are responsible for increasing the immunity power of a person.
Explanation:
Monocytes cells are also called white blood cells. These cells play a role an antigen that fight with outer danger and protect other white blood cells as well and prepare other cells to reduce the dead blood cells and renovate new blood cells.
These cells prevent cancer cells and fight against foreign antigens or particles. The Monocytes are the cells that develop in the bone marrow of a person and develop red blood cells.
In white blood cells, some macrophages cells are called the scavengers in the bone marrow that eat foreign particles and increase the immunity power of the person. The diagnose can be done with the help of blood testing.
Malthus didn't account for diseases or natural disasters in his theory of population growth.
Retina allows the eye to regulate how much lint can enter.