Question

A bacterium divides after every 35 min. If a culture containing\[{10^5}\] cells per ml is grown, then cell concentration per ml after 175 min will be
A. \[175 \times {10^5}\]
B. \[125 \times {10^5}\]
C. \[48 \times {10^5}\]
D. \[32 \times {10^5}\]

Answer 1

Hint:- A form of asexual reproduction typically observed in prokaryotes and few single-celled eukaryotes is binary fission. There is a separation of the parent cell into two new daughter cells in this method of asexual reproduction. This method occurs with the division and duplication of the genetic matter of the parent into two parts, where each daughter cell receives one copy of the DNA of its parent.

Complete Answer:-In prokaryotic organisms, it is a primary method of reproduction. Binary Fission occurs in the cell without any formation of the spindle apparatus. The single DNA molecule initiates replication in this process and then attaches every copy to different parts of the cell membrane. The original (actual) and replicated chromosomes come apart when the cell begins to be pulled apart.
The asexual mode of reproduction, however, has a significant disadvantage. Genetically identical, mirror copies of each other and the parent cell are all the resulting cells. This principle is worked on by most antibiotics. If an antibiotic is susceptible to a parent cell, then all the resulting daughter cells are also vulnerable. If in their genes a mutation occurs, then it can make a specific strain resistant to antibiotics.
The number of bacteria after n division will be \[{2^n}\] if we start from 1 cell. If we start from ‘x’ cells, then after n division they will be \[x \times {2^n}\].
So, till 175 min, \[n = 175 \div 35 = 5\]
i.e., \[{10^5} \times {2^5} = 32 \times {10^5}\]

So, the correct answer is option (D)

Note:- Amoeba is a single-cell organism, and it propagates through binary fission, just like bacteria. The cell divides into two equal-sized daughter cells after replicating its genetic material by mitotic division. Two similar people are produced from a single parent cell in this method. An amoeba that is about to initiate division grows larger, and its nucleus eventually expands and splits into two.