Left: Tobacco plant expressing a firefly gene. The yellow glow is produced by a chemical reaction catalyzed by the protein product of the firefly gene. Right: Pig expressing a jellyfish gene. Researchers injected a jellyfish gene for a fluorescent protein into fertilized pig eggs. One developed into this fluorescent pig. Source: Urry, Lisa A.. Campbell … Continue reading When Gene From A Species Is Injected To Another Species
Photo by Pixabay on Pexels.com Campbell Biology Faithful replication of the genome and repair of DNA damage are important for the functioning of the organism and for passing on a complete, accurate genome to the next generation. The error rate after DNA proofreading and repair is extremely low, but rare mistakes do slip through. Once … Continue reading How DNA Mutation Can Form New Species?
Source: Urry, Lisa A.. Campbell Biology (p. 327). Pearson Education. Kindle Edition. Campbell Biology We cannot attribute the accuracy of DNA replication solely to the specificity of base pairing. Initial pairing errors between incoming nucleotides and those in the template strand occur at a rate of one in 100,000 nucleotides. However, errors in the completed … Continue reading DNA: Proofreading and Repairing
The cancerous cells in nearly all CML patients contain an abnormally short chromosome 22, the so-called Philadelphia chromosome, and an abnormally long chromosome 9. These altered chromosomes result from the reciprocal translocation shown here, which presumably occurred in a single white blood cell precursor undergoing mitosis and was then passed along to all descendant cells. … Continue reading Diseases From Altered Chromosomes: Cri Du Chat and Chronic Myelogenous Leukemia
Source: https://www.nature.com/scitable/content/drawing-of-mitosis-by-walther-flemming-43904/ Source: https://en.wikipedia.org/wiki/Walther_Flemming
Source: Urry, Lisa A.. Campbell Biology (p. 293). Pearson Education. Kindle Edition. Campbell Biology In 1981, a stray black cat with unusual rounded, curled-back ears was adopted by a family in California. Hundreds of descendants of the cat have since been born, and cat fanciers hope to develop the curl cat into a show breed. … Continue reading Did You Know: Cat With Curled-Back Ears
Biochemical tests may detect substances associated with particular disorders, and genetic testing can detect many genetic abnormalities. Karyotyping shows whether the chromosomes of the fetus are normal in number and appearance. Source: Urry, Lisa A.. Campbell Biology (p. 289). Pearson Education. Kindle Edition. Campbell Biology Suppose a couple expecting a child learns that they are … Continue reading Fetal Testings For Genetic Disorders: Amniocentesis and Chorionic Villus Sampling
Source: Urry, Lisa A.. Campbell Biology (p. 286). Pearson Education. Kindle Edition. Campbell Biology The most common inherited disorder among people of African descent is sickle-cell disease, which affects one out of 400 African-Americans. Sickle-cell disease is caused by the substitution of a single amino acid in the hemoglobin protein of red blood cells; in … Continue reading Evolutionary Implications of Sickle-Cell Disease
Campbell Biology A karyotype is a display of condensed chromosomes arranged in pairs. Karyotyping can be used to screen for defective chromosomes or abnormal numbers of chromosomes associated with certain congenital disorders, such as Down syndrome. Source: Urry, Lisa A.. Campbell Biology (p. 256). Pearson Education. Kindle Edition In the picture above, karyotypes are prepared … Continue reading How Karyotypes Are Prepared?
Campbell Biology A series of genetic and cellular changes contribute to a tumor becoming malignant (cancerous). The cells of malignant tumors grow in an uncontrolled way and can spread to neighboring tissues and, via lymph and blood vessels, to other parts of the body. The spread of cancer cells beyond their original site is called … Continue reading Cell Loses Cycle Control and Becomes Cancerous