The NucleusThe Nucleus

Spherical or Oval StructureSpherical or Oval Structure Usually most predominant Usually most predominant

structure in a cellstructure in a cell Most cells have a single nucleusMost cells have a single nucleus

Mature RBCs – no nuclesuMature RBCs – no nuclesu Skeletal Muscle – multinucleatedSkeletal Muscle – multinucleated

Nuclear EnvelopeNuclear Envelope

Double MembraneDouble Membrane Lipid BilayersLipid Bilayers Separates the Nucleus from the Separates the Nucleus from the

CytoplasmCytoplasm Outer membrane is continuous Outer membrane is continuous

with the Rough ERwith the Rough ER

Nuclear PoresNuclear Pores

Openings in the nuclear envelopeOpenings in the nuclear envelope Control movement of substances Control movement of substances

between the nucleus and between the nucleus and cytoplasmcytoplasm

NucleoliNucleoli

Cluster of protein, DNA and RNACluster of protein, DNA and RNA Found within the nucleusFound within the nucleus Site of ribosome productionSite of ribosome production

Cells that produce large amounts of Cells that produce large amounts of protein have very predominant protein have very predominant nucleolinucleoli

GenesGenes

Heredity UnitsHeredity Units Control cell structure and direct Control cell structure and direct

cell activitycell activity Arranged in single file on Arranged in single file on

chromosomeschromosomes Humans cells have 46 chromosomesHumans cells have 46 chromosomes Appear as thin threads called Appear as thin threads called

chromatin when the cell isn’t dividingchromatin when the cell isn’t dividing

GenomeGenome

The total genetic information The total genetic information carried in a cell or organismcarried in a cell or organism

Genomics – the study of the Genomics – the study of the genome and the biological genome and the biological functions of the organismfunctions of the organism

Human Genome ProjectHuman Genome Project

Began in 1990 in an effort to Began in 1990 in an effort to sequence all 3.2 billion (BILLION!) sequence all 3.2 billion (BILLION!) nucleotides of the human genome.nucleotides of the human genome.

CheckpointCheckpoint

Describe the function of the Describe the function of the nucleusnucleus

What are the structures that What are the structures that compose the nucleus?compose the nucleus?

Do all cells have a single nucleus?Do all cells have a single nucleus?