Question

what is the main source of free external dna? click the view theory button if you need guidance with the question.
a) the lysis of cells
b) the mating of two bacteria cells
c) the accumulation of nucleotides in the environment
d) the cell division

Explanation:

To determine the main source of free external DNA, we analyze each option:

• Option a: Cell lysis (breaking open cells) releases their DNA into the environment, making it a key source of free external DNA.
• Option b: Bacterial mating (conjugation) involves direct DNA transfer between cells, not a source of free external DNA in the environment.
• Option c: Nucleotides are building blocks of DNA, not free DNA itself. Accumulation of nucleotides doesn't provide free DNA.
• Option d: Cell division (e.g., binary fission) passes DNA to daughter cells, not releasing free DNA into the external environment.

Answer:

a) The lysis of cells