Mr. Luke’s Life Science

  Mendel experimented with thousands of pea plants to understand the process of HEREDITY. Mendel’s Work What Mendel FoundDefinition Heredity Traits or Characteristics Genetics The passing of physical characteristics from parents to offspring. Factors present within organisms that make them different from others. Mendel saw that some pea plants were tall and some short. As well as some produced green seed and others yellow seeds. The study of heredity

  Mendel started his experiment crossing plants that were PUREBRED by helping with FERTILIZATION. Crossing Pea Plants What Mendel FoundDefinition Fertilization Purebred or Homozygous Hybrid or Heterozygous An organism forms when an egg and sperm join. 2 identical alleles for a trait. Mendel crossed two purebred plants. 2 different alleles for a trait. Mendel found that in F2 Generation that about 75 percent of the offspring had tall stems and 25 percent had short stems.

 Mendel’s Pea Plants

  Mendel concluded that traits get passed on by getting a trait from the female parent and one from the male parent. Mendel’s Conclusion Definition Allele or Gene Dominant Allele Recessive Allele Different forms of a gene Mendel noticed that one factor in a pair can mask the other factor. The trait that always shows up in the organism. Represented by Upper Case letters The trait that is hidden whenever the dominant allele is present. Represented by Lower Case letters

 Genetics of Pea Plants

  Probability is important, because it applies to genetics. It predicts genetic ratio. Probability & Punnett Squares Genetic ProbabilityDefinition Probability Punnett Square Predicts the results of a particular event. Is a chart that shows all the possible combinations of alleles that can result from genetic cross.

 Punnett Square Upper Case Letter: Dominant Allele Lower Case Letter: Recessive Allele ¾= Green ¼= White Hybrid Parents Purebred Parents

Probability:

 Genetic MakeupDefinition Phenotype Genotype Codominance Genetic Makeup Organism’s Physical appearance Organism’s allele combination (Tt, TT, tt) Alleles are neither dominant nor recessive. Both alleles are expressed

  Individually, figure out SpongeBob & Friends genetics. Follow the instructions on the worksheet from H/O Box 1. Bikini Bottom Activity

 Cell Inheritance

  Sex cells go through a process call Meiosis to divide. 4 daughter cells are produced. With half the chromosomes from the parents. Inheritance

 Types of ReproductionsDefinition Sexual Reproduction Asexual Reproduction Sexual/Asexual Reproduction Two parents combine their genetic material to produce a new organism, which differs from both parents. Only one parent produces offspring that are identical to the parent. Ex.: Bacteria

  Each human body cell contains 23 chromosome pairs or 46 chromosomes.  Sex cells have half as many chromosomes than body cells.  According to the chromosome theory of inheritance, genes are carried from parents to their offspring on chromosomes. Genes

 AlleleDefinition Single gene with Two Alleles Single gene with Multiple Alleles Patterns of Inheritance Determine trait with one dominant and one recessive allele. Ex: Widow’s peak, earlobe attached Determines the trait with more than two alleles. Three or more forms of a gene. Ex: Blood Type, Height, Hair Color

  Sex Chromosomes are one of the 23 pairs of chromosomes in each body cell.  It determines whether you are a boy or girl. Sex Chromosomes

  These genes are called SEX-LINKED GENES.  To get the trait a parent must be a carrier.  Carrier: a person who has the gene  Ex: Colorblindness Human Traits Carried on the Sex Chromosome

  The order of the nitrogen bases along a gene forms a genetic code that specifies what type of protein will be produced.  During protein synthesis, the cell uses information from a gene on a chromosome to produce a specific protein.  Before protein synthesis can take place, a “messenger” must first carry the genetic code from the DNA inside the nucleus into the cytoplasm. This is RNA. DNA & RNA

 Types of RNADefinition Messenger RNA Transfer RNA RNA Copies the coded message from the DNA in the nucleus, and carries the message to the ribosome in the cytoplasm. Carries amino acids to the ribosome and adds them to the growing proteins.

  Mutation: Any change in a gene or chromosome.  Mutations can cause a cell to produce an incorrect protein during protein synthesis.  Result: Organism’s trait, or phenotype, may differ from what normally would have been. Mutations

  Substitution:  Deletion: How Mutations Happen: Addition:

  An Abnormal condition that a person inherits through genes or chromosomes. It is caused by changes in the overall structure of the DNA or number of chromosomes. Genetic Disorders Types of Genetic DisordersDefinition Cystic Fibrosis Sickle-Cell Disease The body produces abnormally thick mucus in the lungs and intestines making it hard to breathe. When oxygen concentrations are low, the red blood cell is an unusual shape. It clogs blood vessels and cannot carry as much oxygen as normal cells. It is codominant.

 Genetic Disorders Types of Genetic DisordersDefinition Hemophilia Down Syndrome A person’s blood clots very slowly or not at all. The danger of internal bleeding from small bumps and bruises is very high. A person’s cells have an extra copy of chromosome 21. They have three copies of a chromosome instead of two. It can be caused by chromosomes not separating properly during meiosis.

 Genetic Disorders Cystic Fibrosis Sickle-Cell Disease Down Syndrome Hemophilia

  Pedigree: a chart or “family tree” that tracks which members of a family have a particular trait. Tracing Genetics

  Karotype: a picture of all the chromosomes in a cell.  Genetic Counseling: understanding chances of child having disorder from a genetic counselor. Help With Genetics

 Types of Selective Breeding:Definition: Inbreeding Hybridization Advances in Genetics Selective Breeding: The process of selecting organisms with desired traits to be parents of the next generation. Crossing two individuals that have similar characteristics. Inbred organisms have alleles that are very similar to those of their parents. Breeders cross two genetically different individuals. It is bred to have the best traits from both parents.

 Advances in GeneticsDefinition Cloning Genetic Engineering Advance in Genetics An organism that has exactly the same genes the organism from which it was produced. You can cut a stem off of a plant and then plant that stem. It will grow to be exactly like the plant you cut it from. Genes from one organism are transferred into the DNA of another organism. It can produce medicines and improve food crops. Ex: Engineered bacteria: Insulin, helping crops survive cold temps or poor soil, and cows producing milk with human gene code to help with hemophilia.