Binary Fission Flashcards
Cell Biology (15 cards)
How do prokaryotic cells replicate?
By binary fission
Binary fission is a method of asexual reproduction in prokaryotes.
What happens to the circular DNA during binary fission?
It replicates
The circular DNA is copied before the cell divides.
What is the first step in binary fission?
The circular DNA and plasmid(s) replicate
Plasmids are small, circular DNA molecules that can exist independently of chromosomal DNA.
What occurs after the DNA replicates in binary fission?
The cell gets bigger and the circular DNA strands move to opposite poles
The poles refer to the two ends of the cell.
What happens to the cytoplasm during binary fission?
It begins to divide
This division is essential for forming two separate cells.
What is formed at the end of binary fission?
Two daughter cells
Each daughter cell has one copy of the circular DNA.
How many copies of plasmids can each daughter cell have?
A variable number
The number of plasmid copies can differ between daughter cells.
What conditions allow bacteria to divide quickly?
Warm environment and lots of nutrients
Optimal conditions significantly enhance bacterial growth rates.
How quickly can some bacteria, like E. coli, replicate?
As little as 20 minutes
This rapid replication occurs under ideal conditions.
What happens to bacteria if conditions become unfavorable?
They stop dividing and eventually die
Stressful conditions can halt bacterial reproduction.
What is mean division time?
The average time it takes for one bacterial cell to divide into two
It is a key metric for understanding bacterial growth rates.
How can you find the number of bacteria in a population?
Use the mean division time
Knowing how often a cell divides allows calculation of population growth.
If a bacterial cell has a mean division time of 30 minutes, how many cells are produced after 2.5 hours?
32 cells
Calculation steps include converting time and using the formula for divisions.
Fill in the blank: Each cell divides to produce ______ cells.
2
Each division doubles the number of cells.
Fill in the blank: The number of cells increases by a power of ______ for each division.
2
This exponential growth is characteristic of binary fission.
