“The Nucleus: Not Just a Sack of Chromosomes” Eunnie, Stephen, Shane and Meagan

Electron Micrograph Image from answers.com

Artist’s Rendition or “Nucleus Cartooneus” Image from McGraw-Hill

Eunnie’s Nucleus Comparison

What is the Nucleus? From the latin word for “kernel” or “nut” From the latin word for “kernel” or “nut” Control centre of the cell Control centre of the cell Contains most of the cell’s genetic material Contains most of the cell’s genetic material It’s function is to maintain the integrity of these genes and to control the activities of the cell It’s function is to maintain the integrity of these genes and to control the activities of the cell Found only in eukaryotic cells Found only in eukaryotic cells

Structure Typically located in the centre of the cell Typically located in the centre of the cell Most eukaryotic cells possess one nucleus, although the cells of fungi and some other groups may have several nuclei. Most eukaryotic cells possess one nucleus, although the cells of fungi and some other groups may have several nuclei.

Nuclear Membrane Surrounded by a double membrane, similar to that of the cell, known as nuclear membrane Surrounded by a double membrane, similar to that of the cell, known as nuclear membrane Nuclear pores allow movement of molecules such as mRNA across the membrane Nuclear pores allow movement of molecules such as mRNA across the membrane Nuclear pores are filled with proteins that act as gatekeepers. Nuclear pores are filled with proteins that act as gatekeepers.

Nucleoplasm The nucleoplasm or nuclear sap, a liquid filled with genetic material known as chromatin The nucleoplasm or nuclear sap, a liquid filled with genetic material known as chromatin Chromatin contain the cell’s genetic material, DNA, as well as protein Chromatin contain the cell’s genetic material, DNA, as well as protein When the cell is dividing, chromatin coils into chromosomes which appear shorter and fatter. When the cell is dividing, chromatin coils into chromosomes which appear shorter and fatter.

Nucleolus Produces and assembles ribosomes Produces and assembles ribosomes There can be more than one nucleolus in one nucleus There can be more than one nucleolus in one nucleus The nucleolus is a knot of chromatin The nucleolus is a knot of chromatin

Diseases Chromosomal abnormalities occur when there is an error in cell division following meiosis or mitosis Chromosomal abnormalities occur when there is an error in cell division following meiosis or mitosis Down Syndrome (Trisomy 21) Down Syndrome (Trisomy 21) When an individual has three copies of chromosome 21 When an individual has three copies of chromosome 21 Turner Syndrome Turner Syndrome When an individual is born with only one sex chromosome, an X When an individual is born with only one sex chromosome, an X Cancers, Cystic Fibrosis Cancers, Cystic Fibrosis

Ribosomes Image from answers.com

Ribosomes Serve as the site of protein synthesis Serve as the site of protein synthesis Assembles proteins by the process of translation Assembles proteins by the process of translation Two types of ribosomes: Two types of ribosomes: Free ribosomes, move around freely in the cytoplasm Free ribosomes, move around freely in the cytoplasm Membrane-bound ribosomes, bound to the endoplasmic reticulum Membrane-bound ribosomes, bound to the endoplasmic reticulum Among the most complex molecular assemblies found in cells Among the most complex molecular assemblies found in cells

Diseases Alzheimer’s Disease Alzheimer’s Disease Decreased activity of ribosomal genes Decreased activity of ribosomal genes Associated with psychosis and depression Associated with psychosis and depression

References Biology seventh edition, McGraw-Hill Biology seventh edition, McGraw-Hill Wikipedia Wikipedia Bio 11 textbook Bio 11 textbook