Question

A. List the four phases of mitosis and the major events that occur in each phase.   

      B. Name the two events in meiosis that are critical to zygote development.   

      C. List the steps for sperm entry into the oocyte.   

Answer 1

A. Four phases of mitosis are as

1.Prophase:- During this phase the chromosomes become visible and the centrioles separate taking up positions on the opposite sides of the nucleus.

2. Metaphase:' during this phase the chromosomes line up across the center of the cell.

3. Anaphase:- During this phase the chromosome pairs separate and move toward opposite poles.

4. Telophase:' During this phase the distinct individual chromosomes begin to spread out into a tangle of chromatin.

C.

Step 1:-Numerous sperms penetrate the corona radiata.

Step 2.:' A portion of Zona Pellucida is digested by acrosomal enzymes

Step 3:- The sperm binds with the egg's plasma membrane

Step 4:- the nucleus of sperm enters the egg.

Step 5. :- fusion of Sperm and egg nucleui .