US National Weather Service Philadelphia September Weather data records that on September 28, 1984, the high temperature did not exceed 52 degrees Fahrenheit, the lowest high measured in Philadelphia in the past 69 years.
Vacuoles are generally used to store cell products or protect the rest of the cell from invading microorganisms. The large central vacuole of plant cells is a special case. It is used to store water and cellular wastes and helps maintain the necessary internal pressure of plants called turgor pressure. Structure.
A plant cell vacuole is surrounded by a single membrane called the tonoplast. Vacuoles are formed when vesicles, released by the endoplasmic reticulum and Golgi complex, merge together. Newly developing plant cells typically contain a number of smaller vacuoles. As the cell matures, a large central vacuole forms from the fusion of smaller vacuoles. The central vacuole can occupy up to 90% of the cell's volume. Vacuole Function. Plant cell vacuoles perform a number of functions in a cell including: 1  Turgor pressure control - turgor pressure is the force exerted against the cell wall as the contents of the cell push the plasma membrane against the cell wall. 2  Growth - the central vacuole aids in cell elongation by absorbing water and exerting turgor pressure on the cell wall.