Question

1. list the 7 cells of an angiosperm megagametophyte, and describe the function of each cell. If the function is unknown, state this

2. How is the endosperm of angiosperms similar to the megagametophyte of gymnosperms? How do these tissues differ?

Answer 1

Question 1

Answer: In angiosperms, megagametophyte is also called as embryo sac and consists of seven cells and eight nuclei. The seven cells in the megagametophyte are 3 antipodal cells, 2 synergids, 1 egg cell and 1 large central cell.

Functions of the cell

1. Antipodal cells: These cells are present at the chalazal end of the embryo and it nourishes the embryo providing nutrients. It also helps in the growth and development of endosperm.

2. Synergids: These cells are present at the micropyle end. It produces signal molecules that guides the pollen tube towards the egg cell.

3. Egg cell: These cells are present at the micropyle end. Fertilization of egg cell with male gametes leads to zygote formation that later develops into new seedling.

4. Large central cell: It is located at the center of the embryo sac. It forms endosperm after fertilization with sperm cell. Endosperm contain starch, lipids and proteins. They provide food for the developing embryo or seedlings.