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Shopping for a new pair of genes? That’s not as easy as it sounds, since, as Tim and Moby explain in this BrainPOP gene movie, you’re born with your full set of genes for life! In the movie you’ll discover what a gene is and how it affects characteristics like hair color, eye color, height, and bone structure. You’ll learn how each cell in your body contains long strands of DNA called chromosomes, and how genes come into the picture. You’ll also discover how some genes are recessive and some are dominant, and why no two people (except identical twins) have the same genetic makeup.
A fantastic documentary tracing the earliest human migration on this planet, as shown by our genetic roots. This informative film, full of surprising news, is based on the work of Spencer Wells, who is both innovative scientist and enthusiastic host. He and crew scour the world for indigenous people with deep roots in one place, asking for samples of DNA to test, in order to piece together our “big family” genetic tree. In Indiana Jones mode, Wells tacks down common ancestors and comes up with some surprising candidates which he interviews. The best parts are when he returns with DNA results and we see the diverse ways in which people and tribes react to the news of what science says about their arrival and relations.
An Interactive Animated Nonlinear Tutorial by Eric Martz Adapted for using Jmol instead of Chime, by Angel Herráez Part of Biomodel website by Angel Herráez, Univ. de Alcalá (Spain) Disponible también en español . Também disponível em português .
Cellular Aging: Telomeres - Telomeres Are Chromosome Caps, Telomere Structure, Telomeres And Replication, Telomeres And Replicative Senescence, Telomeres And Premature Aging SyndromesAging is a complex process that occurs on multiple levels. The end result of aging is that life span is limited in multicellular organisms. The cells that make up multicellular organisms also have limited life spans. The limitation on cellular life span is comprised of two parts: (1) cells become unable to continue dividing but remain metabolically active, and (2) at some future time cell death occurs.
The most interesting genetic homologies are in junk DNA. Often called "noncoding DNA," junk DNA has no apparent function or produce no protein but may help regulate the gene. When DNA is transcribed, pieces either do not get transcribed at all or are only partially transcribed, with no functional protein produced. You can cut out or modify most junk DNA without affecting the organism. There are several varieties of junk DNA including pseudogenes, introns, transposons and retroposons. Is Junk DNA Useless?
Both normal cells and cancer cells can be cultured in vitro in the laboratory. However, they behave quite differently. Normal cells pass through a limited number of cell divisions (70 is about the limit for cells harvested from young animals) before they decline in vigor and die. This is called replicative senescence . It may be caused by their inability to synthesize telomerase . Cancer cells may be immortal; that is, proliferate indefinitely in culture.
What is Aging? Aging is the progressive loss of physiological functions that increases the probability of death. This table gives some data. The decline in function certainly occurs within cells.
Each eukaryotic chromosome consists of a single molecule of DNA associated with a variety of proteins. The DNA molecules in eukaryotic chromosomes are linear; i.e., have two ends. (This is in contrast to such bacterial chromosomes as that in E. coli that is a closed circle, i.e. has no ends.) The DNA molecule of a typical chromosome contains a linear array of genes (encoding proteins and RNAs) interspersed with much noncoding DNA. Included in the noncoding DNA are long stretches that make up the centromere and long stretches at the ends of the chromosome, the telomeres .
A technique to keep the tips of your chromosomes healthy could reverse tissue ageing. The work, which was done in mice, is yet more evidence of a causal link between chromosome length and age-related disease.