Question

which statement is true about the differentiated cells in an organism?
o all cells begin with the same basic dna but gain additional genes allowing them to differentiate.
o once fertilization occurs, differentiated cells exist because every cell contains different dna.
o differentiated cells have the same dna, but they do not activate all parts of their dna.
o all cells start with the same dna but lose various non - essential segments of dna during differentiation.

Explanation:

• Option 1: Cells do not lose non - essential DNA segments during differentiation. Differentiation is about gene expression, not DNA loss.
• Option 2: Differentiated cells have the same DNA as they all come from a single - celled zygote (after fertilization). But they don't activate all parts of their DNA. This is correct as different cell types express different subsets of genes.
• Option 3: After fertilization, all cells have the same DNA initially. Differentiated cells don't have different DNA.
• Option 4: Cells don't gain additional genes. Differentiation is due to gene expression, not gene addition.

Answer:

Differentiated cells have the same DNA, but they do not activate all parts of their DNA.