LABORATORY REVIEW
MOLECULAR BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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wrapped around histones in chromatin form
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tightly coiled into chromosomes
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just as it appears in a karyotype
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DNA has no structure during replication
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Detailed explanation-1: -DNA molecules first wrap around the histone proteins forming beads on string structure called nucleosomes . Nucleosomes further [inaudible] and condense/gather to form fibrous material which is called chromatin.
Detailed explanation-2: -These are positively-charged proteins that strongly adhere to negatively-charged DNA and form complexes called nucleosomes. Each nuclesome is composed of DNA wound 1.65 times around eight histone proteins. Nucleosomes fold up to form a 30-nanometer chromatin fiber, which forms loops averaging 300 nanometers in length.
Detailed explanation-3: -The primary protein components of chromatin are histones that help to organize DNA into “bead-like” structures called nucleosomes by providing a base on which the DNA can be wrapped around. A nucleosome consists of 147 base pairs of DNA that is wrapped around a set of 8 histones called an octomer.
Detailed explanation-4: -Chromosomes have proteins called histones that bind to DNA. DNA has two strands that twist into the shape of a spiral ladder called a helix.
Detailed explanation-5: -DNA and histone proteins are packaged into structures called chromosomes.