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Cell Reproduction Intro

Delve into the fascinating world of DNA, genes, and chromosomes in this comprehensive introduction. Explore the structure and function of chromosomes, genes, and DNA replication, and dive into the intricate realm of homologous chromosomes and genetic traits.

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Cell Reproduction Intro

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  1. Cell Reproduction Intro 1) What do you know about DNA, Genes and Chromosomes? 2) What do you want to learn about DNA, Genes and Chromosomes?

  2. 1/29/14 • Find your new seats! • Bellringer: Cell Reproduction Intro • Chromosome Notes • HW: Karyotype Worksheet due Tomorrow

  3. Chromosomes!!!

  4. Introduction to Chromosomes • All of a cell’s DNA is called its “genome” • This genome contains all of the instructions for cell/organism survival and function • A typical human cell has about 3 meters of DNA • DNA is packaged into chromosomes

  5. Chromosomes • PROKARYOTIC Chromosomes are simple circles/clumps of DNA

  6. Chromosomes • EUKARYOITC Chromosomes are very complex • The whole chromosome is made of DNA coiled around proteins called histones

  7. Chromosomes • Homologous Chromosomes: The pairs of chromosomes that exist in sexually reproducing species • In each pair of h. chromosomes one chromosome comes from each parent • They are each called autosomes, and are identical (except X and Y, the sex chromosomes)

  8. Homologous Chromosomes • Homologous chromosomes contain genes for the same traits • Gene: A section of DNA that codes for a specific trait • Ex: Hair color

  9. Homologous Chromosomes • Before a cell divides, the chromosomes copy themselves • The two copies are called chromatids (or sister chromatids), and are attached to one another by a centromere

  10. a a A A replication A a Alleles are different forms of the same gene

  11. 1 chromosome

  12. Karyotype • A picture of all the chromosomes. • It is used to look for abnormalities

  13. Revisit Goals • Find 1-2 goals that you did not meet (or are off-track) …Explain why you didn’t reach these goals • Find 1-2 goals that you didmeet(or are on-track) …Explain why you did reach these goals • Make at least 6 second semester goals on your goal sheet (measurable) 2+ Academic 2+ Personal Improvement 2+ Work/Family/Relationships/Clubs

  14. 1/30/14 • Bellringer: Goals • HW: New Goals • Chromosome Notes (Chromosomal Disorders) • Go over karytype WS • Introduce Chromosomal Disorders Brochure Straight to the Library tomorrow

  15. Chromosome Number • Number varies by species • The number of chromosomes in a SOMATIC CELL (normal body cells) in an organism is known as the DIPLOID/2N number • GAMETES (sex cells, sperm/eggs)contain only half the number of chromosomes and are known as the HAPLOID/N number

  16. Complexity Rankings Rank the below organisms from least to most complex • Humans, Crabs, Potato, Camels, Squirrels, Chickens, Fruit flies, Tomato • Explain the reason behind your rankings.

  17. DIPLOID # OF CHROMOSOMES BY SPECIES: CAMEL = 70 SQUIRREL = 40 CHICKEN = 78 KING CRAB = 208 FRUIT FLY = 8 TOMATO = 24 POTATO = 48 HUMAN = 46

  18. Human Chromosome Number • Human Haploid (N) Number: 23 • Human Diploid (2N) Number: 46 • A human must have all 46 chromosomes to function “properly” • In most cases, humans missing even one chromosome don’t survive development • Monosomy: missing a chromosome • Trisomy: having an extra chromosome

  19. Nondisjunction: when homologous pairs or sister chromatids fail to separate

  20. Down’s syndrome: (trisomy 21) 3 copies of the 21’st chromosome

  21. Cri-du-chat: deletion at the 5th pair • Klinefelter:Extra X chromosome

  22. Goals: • Review Goals and Make new ones…

  23. 1/31/14 • Bellringer: Goals • Go Straight to LIBRARY • Work on Karyotype Worksheet and Brochure…

  24. Bellringer • Define the word “cycle”. • What is the cell cycle? If you don’t know, what would you guess it includes? • Are all cell cycles the same?

  25. 2/3/14 • Objective: To introduce the cell cycle • Bellringer: “Cycle” • Cell Cycle Notes • Homework: • Chromosome WS

  26. Cell Division

  27. Cell Division • Cells divide in order to repair or replace cells that die • Also create new cells in development of a multicellular organism that begins as a zygote

  28. Cell Cycle • Cell Cycle: The life cycle of the cell, from division to division of a cell 5 Stages of the Cell Cycle: • G1: Growth phase of the cell • S: DNA is copied • G2: Prep for mitosis, and organelles are copied • M: Mitosis occurs, nucleus divides • C: Cytokinesis, cell/cytoplasm divides Interphase

  29. MOST OF A CELLS LIFE IS SPENT IN INTERPHASE

  30. What Triggers Cell Division? • Size: If a cell grows so large that there is too much volume for its surface area, it will divide • Growth factors: Chemicals released by cells that encourage other cells to divide

  31. Cell Division • There are 2 types of cell division MITOSIS: • Produces identical cells • Occurs in body cells • Makes diploid cells

  32. 2 Types of Cell Division MEIOSIS: • Produces sex cells (gametes) • Occurs in cells of the sex organs • Makes haploid cells

  33. Bellringer • Define cell cycle • We know cellular division is part of the cell cycle. Name one thing that you think happens during cell division.

  34. 2/4/14 • Bellringer: Cell Cycle • Turn in Chromosome Worksheet • Onion Cell Pre-lab (due Friday)

  35. Bellringer….

  36. 2/5/14 • Bellringer: ????? • Computer Lab Activity

  37. B C A • These are the stages of mitosis. Put them in order, and have a rational for why (you don’t need to write it, but I will ask.) D E

  38. 2/6/14 • Bellringer: Stages of Mitosis • MITOSIS NOTES • Homework: Finish Pre-Lab (I’ll explain later)

  39. Stages of Mitosis Stage 1:Prophase • Chromosomes appear • Nuclear envelope breaks down • Spindle fibers appear • Spindle fibers are protein ropes that help pull chromosomes apart

  40. Late prophase – you can see the spindle fibers

  41. Stages of Mitosis Stage 2: Metaphase • Meta means “middle” • Spindle fibers line up chromosomes on the equator • They attach to the centromeres

  42. Metaphase

  43. Stages of Mitosis Stage 3: Anaphase • Sister chromatids are pulled apart by spindle fibers • Each chromatid (now a chromosome) moves to opposite poles (centrioles)

  44. Stages of Mitosis Stage 4: Telophase • Chromosomes uncoil on separate sides of the cell • New nuclear envelope appears

  45. Cytokinesis: After Mitosis Cytokinesis: • Cell membrane grows in to enclose both cells; cytoplasm divides • In plants, a new cell wall must form

  46. Mitosis produces two identical daughter cells which are diploid

  47. Mitosis in Onion Root

  48. B C A • These are the stages of mitosis. Put them in order, and have a rational for why (you don’t need to write it, but I will ask.) D E

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