The nucleus stores chromatin (DNA plus proteins) in a gel-like substance called the nucleoplasm. The nucleolus is a condensed region of chromatin where ribosome synthesis occurs.
What chromosomes are in the nucleolus?
The nucleolus, which is not surrounded by a membrane, is organized around the chromosomal regions that contain the genes for the 5.8S, 18S, and 28S rRNAs.
Does nucleus contain DNA?
The nucleus contains the cell ‘s DNA and directs the synthesis of ribosomes and proteins. Found within the nucleoplasm, the nucleolus is a condensed region of chromatin where ribosome synthesis occurs. Chromatin consists of DNA wrapped around histone proteins and is stored within the nucleoplasm.
What is the function of Nucleous?
The nucleus controls and regulates the activities of the cell (e.g., growth and metabolism) and carries the genes, structures that contain the hereditary information. Nucleoli are small bodies often seen within the nucleus. The gel-like matrix in which the nuclear components are suspended is the nucleoplasm.
Which nucleus is absent?
It is a membrane-bound organelle that maintains the integrity of the cell. Complete answer: the nucleus is absent in mature sieve tube cells and mammalian erythrocytes.
Does a gene contain many chromosomes?
Genes are contained in chromosomes, which are in the cell nucleus. A chromosome contains hundreds to thousands of genes. Every normal human cell contains 23 pairs of chromosomes, for a total of 46 chromosomes. A trait is any gene-determined characteristic and is often determined by more than one gene.