Ch. 11 & 12

Inheritance


II. Connections


a. Gene Locus & Disulfide Bridge: A disulfide bridge is a bond between sulfur atoms in neighboring cysteine amino acids.  This bond occurs in protein folding to create different proteins.  DNA in the nucleus code for the making of proteins.  DNA strands are very long and can code for various genes.  A gene locus is the specific location of certain genes. 


b. Non-disjunction & 9-triplet Pattern: Non-disjunction is the failure of sister chromatids or homologous chromosomes to separate in meiosis or mitosis.  This results in daughter cells having too many or too few chromosomes.  The microtubules that form the spindle fibers that attach to the kinetochores of the chromosomes are made in a 9-triplet pattern.


c. Autosome & Steroid: Autosomes are the other chromosomes in body cells that are the same in both sexes.  This is similar to the steroids all people have in common, such as cholesterol.  Steroids, such as estrogen and testosterone, that are gender specific are similar to the sex chromosomes are specific chromosomes that determine gender.


d. Polygenic & Glycocalyx: Polygenic inheritance is the inheritance of multiple genes that affect the same trait.  This helps influence genetic variations in DNA, that leads to the evolution of cells, similar to the evolution of eukaryotic cells.  Because eukaryotic cells are more developed than prokaryotic cells, they do not have a glycocalyx, which is a ,eshlike capsul around the prokaryotic cell wall.      


III. Few Essentials


a. Mendel's law of segregation states that genes of homologous chromosomes are separated from each other during meiosis, so that one version of each ends up in different gametes.  Mendel's law of independent assortment states that genes are sorted individually from other genes during meiosis.  Both laws give rise to genetic variations of traits.  The law of segregation during meiosis, when the chromosomes are being pulled apart to opposite poles of the cell so that they end up in different gametes.  The law of independent assortment occurs after meiosis, when the chromosomes have already been sorted for distribution, and occur independently from other types of genes.