More on Genetics

 ______________________- use desired traits to produce the next generation-example-selectively breeding dogs,horses,plants  ______________________crossing dissimilar individuals—often useful in plants  ________________________-continued breeding of of individuals w/similar characteristics Selective breeding hybridization inbreeding

 Mutations are a source of genetic variation  DNA extraction-add chemicals that cause DNA to uncoil from histones and burst out of nucleus  ________________________________- making changes in the DNA code of an organism  _________________________________are used to cut DNA into fragments and gel electrophoresis is used to compare ____________________,or gene composition Genetic engineering Restriction enzymes genomes

 ________________________-DNA produced by combining DNA from different sources  __________________In the process of transforming bacteria,the foreign DNA is joined to this small,circular DNA  _____________________-contain genes from other species---used for making insulin….  A _____________is a member of a population of genetically identical cells from a single source  ___________________________is a picture of chromosomes arranged in ordered pairs Recombinant DNA plasmids transgenics clone karyotypes

Recognition sequences DNA sequence Restriction enzyme EcoR I cuts the DNA into fragments. Sticky end Section 13-2 Restriction Enzymes Go to Section:

Recognition sequences DNA sequence Restriction enzyme EcoR I cuts the DNA into fragments. Sticky end Section 13-2 Restriction Enzymes Go to Section:

DNA plus restriction enzyme Mixture of DNA fragments Gel Power source Longer fragments Shorter fragments Section 13-2 Figure 13-6 Gel Electrophoresis Go to Section:

Fluorescent dye Single strand of DNA Strand broken after A Strand broken after C Strand broken after G Strand broken after T Power source Gel Section 13-2 Figure 13-7 DNA Sequencing Go to Section:

Human Cell Gene for human growth hormone Recombinant DNA Gene for human growth hormone Sticky ends DNA recombination DNA insertion Bacterial Cell Plasmid Bacterial chromosome Bacterial cell for containing gene for human growth hormone Section 13-3 Figure 13-9 Making Recombinant DNA Go to Section:

Recombinant plasmid Gene to be transferred Agrobacterium tumefaciens Cellular DNA Transformed bacteria introduce plasmids into plant cells Plant cell colonies Complete plant is generated from transformed cell Inside plant cell, Agrobacterium inserts part of its DNA into host cell chromosome Section 13-3 Figure Plant Cell Transformation Go to Section:

Cloning Section 13-4 Flowchart A body cell is taken from a donor animal. An egg cell is taken from a donor animal. The fused cell begins dividing, becoming an embryo. The nucleus is removed from the egg. The body cell and egg are fused by electric shock. The embryo is implanted into the uterus of a foster mother. The embryo develops into a cloned animal. Go to Section:

A donor cell is taken from a sheep’s udder. Donor Nucleus These two cells are fused using an electric shock. Fused Cell The fused cell begins dividing normally. Embryo The embryo is placed in the uterus of a foster mother. Foster Mother The embryo develops normally into a lamb—Dolly Cloned Lamb Egg Cell An egg cell is taken from an adult female sheep. The nucleus of the egg cell is removed. Section 13-4 Figure Cloning of the First Mammal Go to Section:

karyotypes

 _______________________-chart that shows a relationship within a family,usually tracking one trait pedigree

A circle represents a female. A square represents a male. A horizontal line connecting a male and female represents a marriage. A vertical line and a bracket connect the parents to their children. A half-shaded circle or square indicates that a person is a carrier of the trait. A completely shaded circle or square indicates that a person expresses the trait. A circle or square that is not shaded indicates that a person neither expresses the trait nor is a carrier of the trait. Section 14-1 Figure 14-3 A Pedigree Go to Section:

 HUMAN BLOOD GROUPS- Rh-single gene w/2 alleles---+ and - /+ is dominant ABO blood groups – genes--- IA,IB,and I or A,B,O

Phenotype (Blood Type Genotype Antigen on Red Blood Cell Safe Transfusions To From Section 14-1 Figure 14-4 Blood Groups Go to Section:

 Autosomal Disorders- Albinism,Cysytic Fibrosis,Galactosemia,PKU,Tay- Sachs  Achondroplasia,Huntington’s.hyperc holesterolemia,Sickle-cell disease  23 pairs of human chromosomes  Xx=female and xy=male

Sex-linked genes:  colorblindness is on x chromosome- rarely expressed in females  hemophilia on x  muscular Dystrophy

 X-Chromosome Inactivation-- Geneticist Mary Lyon found that most of the genes on the 2 nd x chromosome in females are randomly turned off---forming a dense region in nucleus known as BARR BODY/generally not found in males….This explains calico and tortoiseshell female cats!

 Summary of Human Genetic Disorders-  Caused by individual genes-  Sickle-Cell-defective allele for beta globulin causing a sickle shape of RBC’s

 Cystic Fibrosis(CF)—deletion of usually 3 bases ina gene for a protein called CFTR= Cystic Fibrosis Transmembrane Conductance Regulator….which normally allows Cl- ions to pass cell membrane-Phenylalanine is missing and protein folds improperly and is destroyed…causing multiple tissue malfunction-serious digestive and respiratory problems

 Huntington’s Disease-dominant allele for protein found in brain cells---causing a long string of glutamine-mental and muscular deterioration

Read p. 400 to see how genetic disorders can be related to evolutionary advantages.

Chromosomal Disorder:  ___________________- homologous chromosomes fail to separate  __________________-trisomy 21  Turners-only x  Klinefelter’s xxy,xxxy,xxxxy nondijunction Down syndrome

Chromosome # 7 CFTR gene The most common allele that causes cystic fibrosis is missing 3 DNA bases. As a result, the amino acid phenylalanine is missing from the CFTR protein. Normal CFTR is a chloride ion channel in cell membranes. Abnormal CFTR cannot be transported to the cell membrane. The cells in the person’s airways are unable to transport chloride ions. As a result, the airways become clogged with a thick mucus. Section 14-1 Figure 14-8 The Cause of Cystic Fibrosis Go to Section:

Homologous chromosomes fail to separate Meiosis I: Nondisjunction Meiosis II Section 14-2 Nondisjunction Go to Section:

Homologous chromosomes fail to separate Meiosis I: Nondisjunction Meiosis II Section 14-2 Nondisjunction Go to Section:

Homologous chromosomes fail to separate Meiosis I: Nondisjunction Meiosis II Section 14-2 Nondisjunction Go to Section:

Father (normal vision) Colorblind Normal vision Mother (carrier) Daughter (normal vision) Son (normal vision) Daughter (carrier) Son (colorblind) Section 14-2 Male Female Figure Colorblindness Go to Section:

Father (normal vision) Colorblind Normal vision Mother (carrier) Daughter (normal vision) Son (normal vision) Daughter (carrier) Son (colorblind) Section 14-2 Male Female Figure Colorblindness Go to Section:

DNA fingerprinting

Restriction enzyme Chromosomes contain large amounts of DNA called repeats that do not code for proteins. This DNA varies from person to person. Here, one sample has 12 repeats between genes A and B, while the second sample has 9 repeats. Restriction enzymes are used to cut the DNA into fragments containing genes and repeats. Note that the repeat fragments from these two samples are of different lengths. The DNA fragments are separated according to size using gel electrophoresis. The fragments containing repeats are then labeled using radioactive probes. This produces a series of bands—the DNA fingerprint. Section 14-3 Figure DNA Fingerprinting Go to Section:

Normal hemoglobin gene Bone marrow cell Chromosomes Genetically engineered virus Nucleus Bone marrow Section 14-3 Figure Gene Therapy Go to Section:

Human Genome project-analyze human DNA sequence

 Last blank is stem cells