What are Dominant and Recessive? Inheritance patterns Sickle-cell disease is an inherited condition that causes pain and damage to organs and muscles. Instead of having flattened, round red blood cells, people with the disease have stiff, sickle-shaped cells. The long, pointy blood cells get caught in capillaries, where they block blood flow. Muscle and organ cells don’t get enough oxygen and nutrients, and they begin to die. The disease has a recessive pattern of inheritance: only individuals with two copies of the sickle-cell allele have the disease. In addition to causing disease, the sickle-cell allele makes people who carry it resistant to malaria, a serious illness carried by mosquitos. Now let’s look again at the shape of the blood cells. So is the sickle cell allele dominant, recessive, or co-dominant? Protein function If we look at the proteins the two alleles code for, the picture becomes a little more clear. The protist that causes malaria grows and reproduces in red blood cells.
This amazing video shows bacteria evolving in just 10 days Researchers have filmed E. coli growing in a giant petri dish laced with antibiotics to show just how easy it is for bacteria become antibiotic resistant. As you can see in the video below, in the course of just 10 days, the E.coli colonies grow resistant to stronger and stronger antibiotics across several generations, eventually surviving even the strongest doses they come into contact with. "Seeing the bacteria spread for the first time was a thrill… It’s also a powerful illustration of how easy it is for bacteria to become resistant to antibiotics," said one of the researchers, Roy Kishony, from Harvard University. The research isn’t just for a cool video project - the scientists, from Harvard Medical School and the Technion-Israel Institute of Technology in Haifa, are investigating how these bacteria migrate and evolve. The petri dish plate is a 120 cm by 60 cm monster, filled with 14 litres of agar (bacterial food). At each end of the MEGA, no antibiotics are added to the agar mix.
Ödlan som utvecklats till giftig dödsmaskin… Nya fossilfynd tidigarelägger livets uppkomst… Världens äldsta växter upptäckta…