3.5 Flashcards
What are the functions of the nucleus?
- Controls cellular structure
- Directs cellular activities
- Produces ribosomes in nucleoli
What is genomics?
the study of the relationships between the genome and the biological functions of an organism, has flourished.
What is chromatin?
Complex of DNA, proteins, and some RNA
What is genome?
The total genetic information carried in a cell or an organism.
What is nucleosome?
Electron micrographs reveal that chromatin has a beads-on-a-string structure. Each bead is a nucleosome that consists of double-stranded DNA wrapped twice around a core of eight proteins called histones, which help organize the coiling and folding of DNA.
What is linker DNA?
The string between the beads is called linker DNA, which holds adjacent nucleosomes together.
What are chromatin fiber?
In cells that are not dividing, another histone promotes coiling of nucleosomes into a larger-diameter chromatin fiber, which then folds into large loops.
Wha are chromatids?
Just before cell division takes place, however, the DNA replicates (duplicates) and the loops condense even more, forming a pair of chromatids.
