University:
Acadia University
Course:
BIOL-2013 | Cell and Molecular Biology
Academic year:

2024
Views:

47

Pages:

2
Author:

Nabila n.

Binary Fission Prokaryotes, such as bacteria, multiply by simple cell division, known as binary fission. Under ideal conditions (at a suitable temperature and with sufficient nutrients), a bacterium can divide once every 20 minutes. The mean division time is the average amount of time it takes for one bacterium to divide. Step 1 DNA Replication The one circular chromosome replicates. Step 2 Growth The cell gets bigger and becomes elongated as the two chromosomes move to opposite ends of the cell. Step 3 Cell Separation A septum forms down the middle of the cell, and a cell wall begins to develop. Step 4 Daughter Cells Form The cell divides into two daughter cells that are genetically identical. Bacteria and other prokaryotic cells are less complex than eukaryotic cells. Therefore, binary fission is a faster means of cellular division than mitosis. Estimating Bacterial Populations If a bacterium divides once every 20 minutes (its mean division time), the population of the bacteria will double every 20 minutes. If there are 100 bacteria to begin, how large would the bacterial population be 4 hours later? 1 Calculate how many times each bacterium will divide in 4 hours. 4 hours = 240 minutes 240+20= 12 Each bacterium will divide 12 times. 2 Find the population size by using the following equation: Population size = starting amount x 2number of divisions 100 x 212 409,600 The answer expressed in standard form is 4.096 x 105.