At the molecular level

Genes direct the activities of our cells Genes are sections of long molecules called DNA DNA is found in the nucleus of all cells Genetic research shows that changes in the DNA can result in disease by causing cells to function improperly.

Blood disease caused by a change in a gene, which deforms red blood cells. These altered RBC then clog the blood vessels.

Many scientists rely on gene sequencing

DNA is constructed of thousands to millions of molecular subunits, each containing one of four types of bases:  Adenine (A)  Cytosine (C)  Guanine (G)  Thymine (T) The order of bases is different in every gene

Gene sequencing involves mapping the order of all of a gene’s bases By comparing the differences in gene sequences, scientists are able to determine the effects of different genes.

International project to sequence all to human genes and learn more about them. When scientists now these sequences, they can learn the gene functions. They can also use the know sequences to develop methods for diagnosing and treating genetic disorders.

Cancer is the 2 nd leading cause of death Most cancers are caused by damage to genes May introduce mutations (changes in gene sequences) Mutations increase a person’s chance of developing cancer. Cancer is uncontrolled cell growth; caused by gene mutations. This uncontrolled growth can result in a tumour.

Need energy Produce wastes Respond and adapt to their environment Reproduce Grow

Non-cellular structure made up of a stretch of genetic material enclosed in a protein coat. It infects a cell and takes over the host’s reproductive machinery to produce more viruses. Does not have any independent life functions

Is a protein that converts from its normal form into a harmful particle. Can reproduce in living tissue Prion’s are the cause of Bovine Spongiform Encephalopathy (BSE) or “mad cow disease” Does not have independent life functions, so is not a functional unit of life

Cell Culture  isolated cells are placed in test tubes, petri dishes, or flasks. The cells are then supplied with nutrients they need to grow. Cell lines  the cells that result for growth and division. Often used to study cancer cells because cancer cells can divide indefinitely in the laboratory.

Stem cells are “blank slate” cells that divide to produce other types of specialized cells (unlike other body cells which only produce the same type of cell) Most of the rapidly dividing cells of a one-week-old embryo are stem cells. At adulthood there is a limited number of stem cells, mostly located in the bone marrow where new blood cells are produced (and these adult stem cells cannot give rise to all cell types of the body). Scientists are hoping to use them to develop treatments and cures for a variety of diseases and also to grow tissues or organs for transplants

Stems cells can develop into a variety of different tissues and cells. Embryonic stem cell research is particularly controversial because, with the present state of technology, starting an embryonic stem cell line requires the destruction of a human embryo and/or therapeutic cloning. Embryonic stem cellstem cell linehuman embryotherapeutic cloning Some opponents of the research also argue that this practice is a slippery slope to reproductive cloningslippery slopereproductive cloning NOVA | scienceNOW | Stem Cells | PBS Parkinson's – Michael J Fox  Political Commercial Political Commercial Paralysis – Christopher Reeve