Presentation on theme: "Chapter 10 The Cellular Basis of Inheritance"— Presentation transcript:
1 Chapter 10 The Cellular Basis of Inheritance Cells have distinct phases of growth, reproduction, and normal functions.
2 Objectives Describe the purpose of cell reproduction Contrast two ways that organisms reproduce
3 All Cells Come From Cells Where have you heard that before?It is part of the Cell Theory!!Why do organisms need cellular reproduction to occur?Allows living things to repair damageAllows organisms to growAllows organisms to produce offspring
4 Repair and GrowthDid you know that the outer layer of your skin is all dead cells?New cells are continually reproducing underneath and the new cells gradually move upwards to replace dead ones.
6 2 Types of Reproduction Sexual Reproduction: Asexual Reproduction: 2 parentsInvolve gametes (egg & sperm)Genetic material combinesOffspring are genetically different from parentsAsexual Reproduction:1 parentThe process by which a single cell duplicates its genetic materialOffspring identical to parentsExamples- Budding & regeneration
8 Warm Up Match the type of asexual reproduction with its description. _____ buddingA. Small reproductive cells2. _____ binary fissionB. Splitting of cells to make more (bacteria)3. _____ vegetative propagationC. Re-growing lost parts to form a new organism such as in lizards, starfish, and worms.4. _____ regenerationD. “runners”/stems of plants that form identical plants.5. SporesE. A identical organism growing off the side of another until it is able to live on its own.
9 Cell Cycle Objectives Describe the structure of a chromosome (9.2) Name and Describe the stages of the cell cycle (9.2)
10 The Cell CycleThe cell cycle is a regular pattern of growth, DNA replication, and cell division.
11 Interphase (preparation) Gap 1 (G1) – cell growth and normal functionsSynthesis (S) – DNA Replication = a 2nd copy of the genetic material is madeGap 2 (G2) – additional last minute growth & doubling of organellesNote: Mitosis can ONLY occur if the cell is large enough and the DNA is not damaged by the end of interphase!
12 Mitotic Phase (Mitosis or Meiosis) Mitosis is the actual nuclear division of the cell. It is composed of 4 major stages:ProphaseMetaphaseAnaphaseTelophase**Cytokinesis = the final splitting of the cytoplasm and “pinching” of the cell membranes.
13 Cells divide at different rates. The rate of cell division varies with the need for those types of cells.
14 Cell size is limited…Eventually they MUST divide! S.A / Volume Ratio needs to be high…or diffusion (essential for cell life) suffers!
15 WARM-UP What part of the cell cycle is the “preparation” part? What part of the cell cycle is the actual splitting of the nucleus?
16 Surface area must allow for adequate exchange of materials.! Therefore…..Cells that must be large have unique shapes.With a crazy shape, their surface area/volume ratio remains HIGH and diffusion of materials into/out of them is fast enough to survive!
17 Surface Area vs. Volume of Cells (Relay) GAME How the game works:There will be 4 teams. Each team will get a chance to work with each shaped cell.Your team must get the provided molecules (beads) into the nucleus in the shortest amount of time!Only 1 team member can go into the cell at a time and all team members must participate…..so its a relay!!!Be strategic!!!!Remember your times for the data table!Cell BCell A
18 DATA TABLE (write time & a team member’s name) Cell A (long cell in hallway)Cell B (round one in room)AVERAGE TIME
19 WRAP UPWhat process was represented by the transferring of beads (molecules) into the center (nucleus) of the cells?Which cell went faster? (round or long?)WHY did the above cell go faster?This activity represented that a cells Surface Area/Volume Ratio must be ___________ (high or low) in order for it to be efficient and survive.
22 9The Cell Cycle in body cells: Mitosis and cytokinesis produce two genetically identical daughter cells.
23 Events that occur During Interphase (G1) - The cell grows and performs normal functions(S) The DNA is duplicated (via DNA Replication)(G2) The cell undergoes last minute growth & organelle duplicationParent cellcentriolesspindle fiberscentrosomenucleus withchromatinInterphaseNuclear Envelope
24 Chromatin condenses at the start of mitosis into chromosomes!. …By having the DNA wrap around proteins.…The end product is chromosomes!!
25 Remember: DNA + proteins is called chromatin. chromatidtelomerecentromereCondensed, duplicated chromosomeOne half of a duplicated chromosome is a chromatid.Sister chromatids are held together at the centromere.
26 Events that occur during Prophase Chromatin (DNA) condensesand chromosomesare visiblespindle fibers formNuclear envelopedisappearsNuclear envelopeBreaking apartSister ChromatidsSpindles Forming
27 Events that occur during Metaphase chromosomes line up in the middle of the cellSpindle fibers attach to centromeres (between sister chromatids)Sister ChromatidsCentromere
28 Events that occur during Anaphase Sister chromatids separate (at the centromere)Spindle fibers pull identicalchromosomes to oppositesides of the cell.ChromosomeSpindle FiberCentromere
29 Events that occur during Telophase & Cytokinesis The new nuclei formChromosomes begin touncoilNuclear envelope reappearsCytokinesis:Cell splits into twoTwo identical daughtercells formIdentical ChromosomesNuclear EnvelopeTwo Identical Daughter Cells Form (Cytokinesis)
30 Two Identical Daughter Cells form After Cytokinesis In animal cells, the membrane pinches closed (cleavage furrow)In plant cells, a cell plate forms.nucleus withchromatin
31 Animal Cells = Cleavage Furrow (pinches the 2 daughter cells apart) Plant Cells = cell plate forms (to divide the 2 daughter cells)
32 Crash Course – Mitosis Mitosis: Splitting Up is Complicated - Crash Course Biology #12 - YouTube
36 Find a cell in the following stages: Interphase, Prophase, Metaphase, Anaphase, and Telophase of mitosis.
37 CancerDo you know anyone (or of anyone) who has been diagnosed with cancer?If so, what cancer did they have? And what types of things did they go through?What type of cancers do you think are most prevalent?
38 Cancer … Mitosis Out of Control!!!! Cancer results from out-of-control cell production.Abnormal masses of cells are called tumors.
39 Two Types of Tumors Tumors can either be: Benign – abnormal mass of normal cellsMalignant – mass of cells resulting from the reproduction of cancer cells.Brain Tumor (MRI)
40 MetastasisWhen cancer cells break off tumors and travel/spread to other places in the body, the cancer is said to have metastasized.Video: How cancer spreads - MayoClinic.com
41 Cancer Treatment Surgery Radiation Therapy Chemotherapy Unwanted Side Effects – nausea, damage to organs, sterility, hair loss, etc.
42 Common Cancers Melanoma (type of skin cancer) Leukemia (cancer of the circulatory system – blood)Lung CancerColon CancerBreast CancerBladder Cancer
44 Warm - upName the 3 reasons cell reproduction is necessary for organisms?
45 Meiosis Objectives Contrast haploid and diploid cells Summarize the process of meiosisCompare mitosis & meiosisExplain how genetic variation occurs in offspring of populations
46 9KEY CONCEPT Gametes (sex cells) have half the number of chromosomes that body cells have and they reproduce via meiosis (not mitosis)
47 4 haploid (n) gametes/sex cells Mitosis vs. MeiosisMitosis and meiosis are types of nuclear divisionthat make different types of cells.Occurs in testes & ovariesMitosis occurs in body cellsMitosis makes2 diploid (2n) cellsMeiosis makes4 haploid (n) gametes/sex cells
48 Sexual Reproduction relies on Meiosis Meiosis – a type of cell division that produces gametes/sex cells (egg & sperm)Meiosis occurs in sex organs (testes & ovaries)Still part of cell cycle (simply replace mitosis with meiosis)
49 You have somatic cells and germ cells. (body cells) (sex cells)Germ cells develop into gametes (sperm & eggs)Germ cells are located in the reproductive organs.Gametes have DNA that can be passed to offspring.body cells (muscle cells)sex cells (sperm)sex cells (egg)
50 Each of your cells have:. 1. autosomes (regular ones). 2 Each of your cells have: 1. autosomes (regular ones) 2. sex chromosomesYour body cells have a total of 23 pairs of chromosomes.That is ___ total chromosomes.Chromosome pairs # 1-22 are autosomes. (=44 chromosomes)Pair # 23 are the Sex chromosomes, X and Y, (determine gender)Girl = X XBoy = X Y
51 Quick Check / ReviewMeiosis is a type of cell division that makes ______ cells in the ______ & _______ (organs) of our bodies.Somatic (body) Cells reproduce through ____________ (mitosis or meiosis).Sex Cells reproduce through __________ (mitosis or meiosis)How many total chromosomes are in your body cells???? _______ (hint: 23 pairs)
53 Body cells are diploid Gametes (sperm & eggs) are haploid Fertilization joining of egg and sperm; occurs in sexual reproduction, results in a diploid zygoteDiploid (2n) cells have two copies of every chromosome. = 46 chromosomesBody cells are diploid*Total = 46 Chromosomes(A set of chromosomes (23) come from each parent)
54 Haploid (n) cells have only one copy of every chromosome (or ½ the normal amount) Gametes (sperm & eggs) are haploid.Total = 23 chromosomes (that’s ½ of 46!!)
55 Diploid (2n) vs. Haploid (n) Cells Body CellsContain 2 copies of each chromosomeTotal = 46 chromosomes(44 autosomes & 2 sex)Reproduce through mitosisSex CellsContain 1 copy of each chromosomeTotal = 23 chromosomes(22 autosomes & 1 sex)Reproduce through meiosis
57 Final product: 2 diploid Final product: 4 gametes Mitosis vs. MeiosisMitosis and meiosis are types of nuclear divisionthat make different types of cells.Mitosis occurs in body cellsOccurs in testes & ovariesFinal product: 2 diploid(2n) cellsFinal product: 4 gametes(haploid (n) cells)
59 How do we get genetic variation? During Prophase 1 (of Meiosis 1)…homologous chromosomes, while paired in “tetrads” undergo “Crossing Over” and swap genes for traits.This creates genetic variation in populations!!!
60 Crash Course - MeiosisMeiosis: Where the Sex Starts - Crash Course Biology #13 - YouTube