Cell Communication Objectives Describe basic chemical processes for cell communication shared across evolutionary lines of descent. Generate scientific questions involving cell communication as it relates to the process of evolution. Describe features of a cell signaling pathway. Explain cell communication through cell to cell direct contact or through chemical signaling. Create representations that depict how cell to cell communication occurs by direct contact or from a distance through chemical signaling. Describe a model that expresses the key elements of signal transduction pathways by which a signal is converted to a cellular response. Justify claims based on scientific evidence that changes in signal transduction pathways can alter cellular response. Describe a model that expresses key elements to show how change in signal transduction can alter cellular response Explain how certain drugs affect signal reception and consequently, signal transduction pathways. Cell division Objectives Outline the stages in the cell cycle, including interphase (G1, S, G2), mitosis and cytokinesis. State that tumours (cancers) are the result of uncontrolled cell division & that these can occur in any organ or tissue. State that interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts. Describe the events that occur in the 4 phases of mitosis (prophase, metaphase, anaphase & telophase). Note: Include supercoiling of chromosomes, attachment of spindle microtubules to centromeres, splitting of centromeres, movement of sister chromosomes to opposite poles, & breakage & reformation of nuclear membranes. Textbooks vary in the use of the terms chromosome & chromatid. In this course, the two DNA molecules formed by DNA replication are considered to be sister chromatids until the splitting of the centromere in anaphase; after this, they are individual chromosomes. Explain how mitosis produces two genetically identical nuclei. State that growth, embryonic development, tissue repair and asexual reproduction involve mitosis. Make predictions about natural phenomena occurring during the cell cycle. Explain, using visual representations or narratives, how DNA in chromosomes is transmitted to the next generation via mitosis, or meiosis followed by fertilization. Outline the connection between meiosis and increased genetic diversity necessary for evolution. Evaluate evidence provided by data sets to support the claim that heritable information is passed from one generation to another generation through mitosis, or meiosis followed by fertilization. State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei. Define homologous chromosomes. Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells. Note: Crossing over is the exchange of genetic material between non-sister chromatids during prophase I. Names of the stages of meiosis are required. Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21). State that, in karyotyping, chromosomes are arranged in pairs according to their size and structure. State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities. Analyze a human karyotype to determine gender and whether non- disjunction has occurred.