Mitosis Lab DO NOW On loose-leaf Identify how many cells are in: Interphase - _____ Prophase - _____ Metaphase - _____ Anaphase - _____ Telophase/Cytokinesis - _____

Diagram 1 – On Lab

Number of cells in phase Obtain Your Data Table 1. - Results of counting cells in each phase of mitosis and interphase PHASE Number of cells in phase Time in minutes Interphase   Prophase Metaphase Anaphase Telophase Total Number  Time for a phase = 𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒄𝒆𝒍𝒍𝒔 𝒊𝒏 𝒂 𝒑𝒉𝒂𝒔𝒆 𝑻𝒐𝒕𝒂𝒍 𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒄𝒆𝒍𝒍𝒔 𝒄𝒐𝒖𝒏𝒕𝒆𝒅 x 720  

DO NOW - on loose-leaf What do multicellular organisms use mitosis for? Describe the offspring produced during mitosis Complete the Mitosis diagrams showing amount of DNA: 46 4 2n

Reproduction What is reproduction? Organisms make more of themselves Necessary for the continuation of a species Not necessary for the survival of an individual organisms What are the TWO types of Reproduction? Asexual Sexual

Asexual Reproduction Why is asexual reproduction necessary? Unicellular Organisms Cell division / reproduction One organism makes an EXACT copy of itself Multicellular Organisms Tissue repair Skin cells make more skin cells (EXACT copy) Liver cells make more… Liver cells (Exact Copy)

Asexual Reproduction How do organisms produce exact copies of themselves? Process called MITOSIS What is Mitosis? Type of cell division Produces TWO daughter cells Daughter cells are EXACTLY like each other and the Parent Cell DNA information and amount are all the SAME

Complete the Diagrams for Mitosis   46 2n Pony Describe the relationship between each daughter cell and the relationship between the daughter cells and parent cell.

Do Now 20 Complete Questions: 1 2a, 2b 3

Do Now - On loose-leaf What phase of the cell life cycle does each letter show: What happens during “Letter D?” What happens during “Letter B” A - ____________ B - ____________ C - ____________ D - ____________ E - ____________

Mitosis So does every cell use Mitosis? What cells DO NOT use Mitosis? Sperm Cells Egg Cells

Sperm and Egg are DIFFERENT Then how are sperm and egg cells made? Process known as Meiosis Sperm and Egg Cells are the only TWO cells that USE Meiosis DO NOT use Mitosis Sperm & Egg cells, along with Meiosis, are only USED IN Sexual Reproduction

Type 2 - Sexual Reproduction Two parents Specialized sex cells & sex organs Creates VARIATION Offspring different than parents Do you look like the person sitting next to you? Do you look exactly like your brother, sister, mother, father or cousin? So, how do humans reproduce? Note: Sperm and egg are specialized sex cells called gametes All other cells in the body are body or somatic cells

Sexual Reproduction & Meiosis Sperm & Egg (gametes) Formed by process called Meiosis Are HAPLOID – only have half the Chromosomes (DNA) of a body cell Human Body cells have 46 chromosomes… egg and sperm only have Sperm and Egg fuse This is called fertilization Meiosis & Fertilization guarantee VARIATION No variation in asexual reproduction (Mitosis) 23 Explain the sex cells and sex organs… what are they

What is Meiosis? Only makes TWO types of cells in our bodies: Sperm Egg Occurs only in our Our Testes & Ovaries Gametes Gonads Explain the sex cells and sex organs… what are they

What is Meiosis? Meiosis Starts with one diploid Cell (2n) Meiosis has 2 divisions Produces four UNIQUE haploid cells (n) (gametes) Explain the sex cells and sex organs… what are they Look at the chromosomes. They are different for each cell!

What is Meiosis? Meiosis Starts with one diploid Cell (2n) Meiosis has 2 divisions Produces four UNIQUE haploid cells (n) (gametes) Complete the diagrams Explain the sex cells and sex organs… what are they

Do Now 20 Complete Do Now 20

What is Diploid? Diploid Cells (2n) – Cells that have two chromosomes that code for the same thing (eye color, height, hair color etc…) One chromosome comes from the mother and one from the father A B How many chromosomes in cell A and B? Explain the sex cells and sex organs… what are they Are both cells diploid(2n)? Why? From Father From Mother Codes for hair color & eye color Codes for hair color & eye color

What is Haploid? Haploid Cells (n) – Cells that have one chromosome that codes for certain traits Sperm only has fathers DNA set Egg only has mothers DNA set Explain the sex cells and sex organs… what are they From Father From Mother One codes for Hair color and one codes for Eye color One codes for height and one codes for insulin hormone

How many chromosomes? Cell A - Cell B - A B From Father From Mother Explain the sex cells and sex organs… what are they From Father From Mother One codes for Hair color and one codes for Eye color One codes for height and one codes for insulin hormone

Do Now 22 Complete Questions: # 1, 2, 3, 4, 5, 13

Complete the Diagram on Meiosis Use 2n Explain the sex cells and sex organs… what are they

What is Meiosis? Compare and contrast Mitosis and Meiosis? Mitosis Explain the sex cells and sex organs… what are they

Process of Meiosis P-M-A-T How many cell divisions in Meiosis? 2 Describe the cells produced from Meiosis: Different from one another and the parent cell 4 Unique, Haploid (n) cells are produced from one Diploid Cell Create gametes (sperm and eggs) Gametogenesis = creation of Sperm & Egg What creates or guarantees genetic variation in sexual reproduction? Meiosis Fertilization

Do Now 22 Complete Questions: # 6 – 12 (finish sheet)

First Division of Meiosis

Process of Meiosis: Creating Variation P-M-A-T Interphase I Haploid or Diploid? Chromosomes (DNA) duplicates and makes sister chromatids Just like during Mitosis Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T Prophase I Homologous chromosomes pair up Homologous Chromosomes Same size Code for same traits Hair color, eye color etc… Haploid or Diploid? Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T Prophase I Crossing Over occurs!!!!!!! Physical transfer of genetic material Creates VARIATION Haploid or Diploid? How is this different than Mitosis? Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T Metaphase I Haploid or Diploid? Homologous Chromosomes line up in the middle How is this different than Mitosis? Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T Haploid or Diploid? Anaphase I Homologous chromosomes separate into Two Different Haploid cells Disjunction – equal separation of homologous chromosomes How is this different than Mitosis? Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T Anaphase I Haploid or Diploid? Non-Disjunction Unequal separation of homologous chromosomes Can happen during: Anaphase I Anaphase II Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

2n+1 Body Cell Non-disjunction Extra chromosome from unequal division of chromosomes Trisomy 21 – down syndrome Normal 2n Body Cell DNA Normal Disjunction

Process of Meiosis: Creating Variation P-M-A-T Haploid or Diploid? Telophase I and Cytokinesis TWO (2) Unique Haploid cells are created Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Second Division of Meiosis

Process of Meiosis: Creating Variation Second Division P-M-A-T II Just like mitosis Chromosomes line up at middle Sister chromatids split Difference = 4 Haploid Cells form at the end (gametes) Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color Father’s chromosomes: Blue – codes for eye color Red – codes for hair color

Process of Meiosis: Creating Variation P-M-A-T II Second Division Haploid or Diploid? Why? Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

Process of Meiosis: Creating Variation Non-Disjunction P-M-A-T Father’s chromosomes: Blue – codes for eye color Red – codes for hair color Mother’s chromosomes: Yellow – codes for eye color White – codes for hair color

So, meiosis makes our gametes? Yes!

Spermatogenesis Spermatogenesis Formation of male gametes (sperm) All four haploid cells are functional sperm Haploid (n) (23 chromosomes)

Oogenesis Oogenesis Formation of female gametes (eggs) One functional egg & three nonfunctional polar bodies Haploid (n) (23 chromosomes)

Sperm and eggs are formed! Now what? Sexual Reproduction & Fertilization can take place!

Meiosis Video https://www.youtube.com/watch?v=35ncSrJOwME (9 min)

Complete these definitions on back of note packet or loose-leaf Gamete Gonad Diploid Haploid Gametogenesis Zygote Fertilization Chromosome Gene Nucleus

Explain the differences between the process of mitosis and the process of meiosis

Meiosis Worksheet

Meiosis Worksheet