Determine the correctness or otherwise of the following Assertion [A] and the Reason [R] regarding mammalian cells.
Assertion [A]: Cells use Ca²⁺ and not Na⁺, for cell to-cell signaling.
Reason [R]: In the cytosol, concentration of Na⁺ is lower than that of Ca²⁺

Which one of the following changes occurs in a directionally migrating eukaryotic cell?

A. The ER is fragmented

B. The mitochondrial membrane potential drops

C. The nucleus moves towards the back and behind the Golgi

D. The Golgi is fragmented

Structured William's model
P. Can describe the changes in intracellular components of the cell during growth.
Q. Cannot describe the death phase of the cells.
R. Can describe the variation of size of cells in the different phases of growth.
S. Cannot describe the lag period of growth.
Which one of the following is correct?

A. P, Q and S only

B. P, Q and R only

C. Q, R and S only

D. P, R and S only

Metaplasia represents

A. Uncontrolled proliferation of cells initiated at the metaphase of cell cycle

B. Transformation of one differentiated cell type to another

C. Cell proliferation during metamorphosis

D. A measure of metabolic activity in hyperplastic cells

Which one of the following organelles disappears during cell division and is regenerated in the daughter cells?

A. Endoplasmic reticulum

B. Golgi

C. Mitochondria

D. Peroxisomes