Presentation on theme: "Biology 101: Unit 5 First few days: Cell Cycle, Asexual vs Sexual Reproduction, Chromosome Number THE ANSWER TO YOUR QUESTION IS: YES!"— Presentation transcript:
Biology 101: Unit 5 First few days: Cell Cycle, Asexual vs Sexual Reproduction, Chromosome Number THE ANSWER TO YOUR QUESTION IS: YES!
GENETICS II: Cell Cycle Asexual vs Sexual Reproduction Meiosis (friday) Mon- finish meiosis- Reebops Lab DNA Mutations Genetics Disorders
IMPORTANT DATES TO KNOW: Benchmark: USA TEST PREP: Thurs 10/17 MIDTERM: 10/18: will include all information up to this point on this test
Getting Started… If you were the prosecutor in this criminal case, who would you want arrested? Why? What is the DNA Technology that is used in this situation called?
How does cell division differ in uni and multicellular organisms? Unicellular: reproduce by binary fission, budding, fragmentation= asexual reproduction Multicellular: involves the production of sex cells
Compare internal/external fertilization Fertilization- joining of sex cells External fertilization- gametes are released into the environment Internal fertilization- sperm are deposited inside females body
What are chromosomes? Carriers of genetic material found in nucleus Made up of DNA
What is involved in Chromosome structure? Chromosomes are made up of two chromatids which are held together with a centromere Human chromosome number is 46 in body cells; 23 in sex cells
Compare haploid/diploid number Haploid number- (n) half-number typically found in gametes only Diploid number- (2n) double-number found in somatic cells (body cells)
How is gender determined in humans? Females have XX as last set of chromosomes (sex chromosomes) All eggs are X Males have XY as last set of chromosomes Half of sperm are X sperm; half are Y sperm Males determine gender of offspring
Activity: Chromosome Worksheet: Chromosome Number practice
What is the cell cycle? Sequence of growth and division in the cell 1. Interphase is the growth period where replication occurs 2. Mitosis
What is mitosis? division of cells producing two cells with the same number of chromosomes Ex: 46 chromosomes in human body cells, so ALL body cells should have 46
What is involved in Prophase? Chromatin (normal form of DNA) coils into chromosomes The nucleus disappears Centrioles form and move to opposite poles of cell Spindle fibers form from centrioles and begins to cross cell
What is involved in Metaphase? Chromosomes line up in the middle of the cell Spindle forms across the cell from centrioles
What is involved in Anaphase? Spindle fibers begin to shorten Chromosomes pulled apart Move to opposite poles
What is involved in Telophase? Chromosomes unwind into chromatin Spindle fibers break down Nucleolus and nuclei reform Plasma membrane begins to pinch in
What is Cytokinesis? Division of cytoplasm In animal cells: cell membrane continues to pinch in until two cells are formed In plant cells: cell plate forms in center of cell and eventually splits cells At the end of mitosis, two new cells are produced; called daughter cells
Thurs: 10/10 Quick Quiz 1 1. Which part of the cell cycle involves the copying of the DNA? a. interphase b. mitosis 2. What is the division of the cytoplasm called? a. cytolysis b. cytofission c. cytokinesis A.Prophase B. Metaphase C. Anaphase D. Telophase 3. Which phase involves the splitting of the chromosomes? 4. Which phase involves the chromosomes lining up in the center of the cell? 5. Which phase involves the formation of chromosomes? 6. In which phase does a cell plate form in a plant cell? 7. The nucleus begins to disappear and spindle fibers begin to form across the cell?
Review of The Cell Cycle: Mitosis Chromosome Structure/Number Gender Interphase Mitosis- P-M-A-T-Cyto Review Mitosis and Cancer Reading
Activity 1: Cell Cycle Using supplies available in class, create a Cell Cycle Flipbook: MUST INCLUDE: 1)ALL steps of the cell cycle: Interphase- Cytokinesis 2)Show LABELED diagrams and a description of what is happening in each stage
Activity 2: Mitosis Lab Onion Root Tip Lab 1)Complete lab in lab area; 2)Use caution with microscope slides and the microscope
Asexual vs. Sexual Repoduction Asexual Reproduction –No sperm or egg are used –Newly produced cells are genetically identical to parent cell- clones –If it occurs in… human body cells (like the skin)- called mitosis single-celled organisms like bacteria or protists- called binary fission simple animals (like sponge)- called budding Sexual Reproduction –Sperm and egg are produced & fused –Newly produced cells are genetically different from each other and the parent cell. –This creates genetic diversity –If it occurs in human body cells- called meiosis Single-celled organisms like bacteria or protists- called conjugation.
Homework: Thurs 10/10 HW: Why Sex is Good Case Study- ALL **If needed: Mitosis matching WS for practice with stages