Question

what threadlike structure is dna integrated into? chromatin nucleus nitrogen base karyotype

Explanation:

Chromatin is a thread - like structure composed of DNA and proteins (histones). The nucleus is an organelle that contains chromatin (and thus DNA). A nitrogen base is a component of nucleotides (the building blocks of DNA). A karyotype is an image of an individual's chromosomes. Since the question asks for the thread - like structure that DNA is integrated into, chromatin is the correct answer.

Answer:

Chromatin