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Presentation on theme: "THE ANSWER TO YOUR QUESTION IS: YES!"— Presentation transcript:

Biology 101: Unit 5 First few days: Cell Cycle, Asexual vs Sexual Reproduction, Chromosome Number

2 GENETICS II: Cell Cycle Asexual vs Sexual Reproduction
Meiosis (friday) Mon- finish meiosis- Reebops Lab DNA Mutations Genetics Disorders

Benchmark: USA TEST PREP: Thurs 10/17 MIDTERM: 10/18: will include all information up to this point on this test

4 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?

5 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

6 Compare internal/external fertilization
Fertilization- joining of sex cells External fertilization- gametes are released into the environment Internal fertilization- sperm are deposited inside female’s body

7 What are chromosomes? Carriers of genetic material found in nucleus
Made up of DNA

8 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

9 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)

10 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

11 Activity: Chromosome Worksheet: Chromosome Number practice

12 What is the cell cycle? Sequence of growth and division in the cell
1. Interphase is the growth period where replication occurs 2. Mitosis

13 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

14 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

15 What is involved in Metaphase?
Chromosomes line up in the middle of the cell Spindle forms across the cell from centrioles

16 What is involved in Anaphase?
Spindle fibers begin to shorten Chromosomes pulled apart Move to opposite poles

17 What is involved in Telophase?
Chromosomes unwind into chromatin Spindle fibers break down Nucleolus and nuclei reform Plasma membrane begins to pinch in

18 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

19 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 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?

20 Review of The Cell Cycle: Mitosis
Chromosome Structure/Number Gender Interphase Mitosis- P-M-A-T-Cyto Review Mitosis and Cancer Reading

21 Activity 1: Cell Cycle Using supplies available in class, create a Cell Cycle Flipbook: MUST INCLUDE: ALL steps of the cell cycle: Interphase-Cytokinesis Show LABELED diagrams and a description of what is happening in each stage

22 Activity 2: Mitosis Lab Onion Root Tip Lab Complete lab in lab area;
Use caution with microscope slides and the microscope

23 Asexual vs. Sexual Repoduction
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. 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

24 Homework: Thurs 10/10 HW: Why Sex is Good Case Study- ALL **If needed: Mitosis matching WS for practice with stages


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