MEIOSIS Compare & Contrast Mitosis & Meiosis

Journal Week 19- Mon 1/19 MLK Jr Day- NO SCHOOL

Journal Week 19- Tues 1/20 J- Briefly describe the process of mitosis in 5 sentences (what types of cells does it happen in, what is the product, how many cells are made, why does it occur, etc…) TI- Mutations wkst CW- Human Traits Survey, Set up folder, Mendel Worksheet HW- finish Mendel worksheet, Interactive reader pgs (highlight & answer) DUE Fri 1/23

Update your table of contents AND title & number all pages Left side, pg #Right Side, pg # Gregor Mendel, 23Meiosis Vocab, 24 Chromosome Reinforcement, 25 Meiosis Guided Notes, 26 Meiosis I, 27Meiosis II, 28 Meiosis Reinforcement, 29 Genetic Variation Reinforcement, 30

Journal Week 19- Wed 1/21 J- 1.Through what process, (Mitosis or Meiosis) do we create gametes ex. sex cells, egg & sperm? 2.Most cells in the body are produced by _________. 3.Only gametes are produced by _________. TI- checking Mendel worksheet (10 pts) CW- Meiosis Guided Notes, Chromosome Power Notes & Reinforcement HW- Interactive reader pgs (highlight & answer) DUE Fri 1/23

What is it? Sperm and egg.

Meiosis -the production of haploid cells with unpaired chromosomes - word means "to diminish".Meiosis -the production of haploid cells with unpaired chromosomes - word means "to diminish". ◦ Key points of Meiosis The process results in 4 daughter cellsThe process results in 4 daughter cells Daughter cells are haploid (N)Daughter cells are haploid (N) Daughter cells have unique combinations of chromosomesDaughter cells have unique combinations of chromosomes Produces Gametes (sperm & eggs)Produces Gametes (sperm & eggs)

Meiosis ensures variability in offspring Why do you think this is important? Gametes combine to create a zygote which is diploid (2N) - process of sexual reproduction Which is haploid? Which is diploid? -IDENTIFY EACH LEVEL ON YOUR NOTES!

Haploid Vs. Diploid Haploid: gamete cells that have only 1 set of the chromosomes, represented as “N” Haploid: gamete cells that have only 1 set of the chromosomes, represented as “N” Diploid: cell that has both sets (2) of chromosomes, represented as “2N” Diploid: cell that has both sets (2) of chromosomes, represented as “2N” Which karyotype is diploid? Haploid? What sex are they?

Chromosome Structure Chromosomes also have banding patterns unique to each one. These bands are caused by certain dyes. Chromosome banding can help to determine homologs on a karyotype. Each chromosome has mane alleles, or alternate forms of genes

Figure 10.1b How many of these terms did you recognize?!

Homologous Chromosomes - each chromosome has a match, called a homolog. This is why normal organisms always have an even number of chromosomes. One homolog you received from your mother, the other you received from your father. They are not exactly alike, but they are the same size, shape, and have the same banding pattern. Chromosomes are numbered according to their size. Karyotype showing homologous pairs.

Sex Chromosomes The last set of chromosomes are the sex chromosomes. In humans... XX = female XY = male

How do you become Diploid? At fertilization, 23 chromosomes are donated by each parent. (total = 46 or 23 pairs). Gametes (sperm/ova): ◦ Contain 22 autosomes (non sexual) and 1 sex chromosome. ◦ Are haploid (haploid number “n” = 23 in humans). Fertilization results in diploid zygote. ◦ Diploid cell; 2n = 46. (n = 23 in humans)

Meiosis 1 & 2 + Mitosis Vocabulary Mitosis: cell division in eukaryotes Meiosis: process of reduction division (cutting the number in half) that separates homologous chromosomes from a diploid cell. ◦Meiosis 1 & 2 divisions Chromosome: tightly coiled genetic material found in the nucleus Chromatid: one of the 2 identical “sister” parts of a duplicated chromosome Crossing Over: homologous chromosomes pair up in tetrads and exchange portions of their chromatids Tetrad: homologous chromosomes paired together, 4 sister chromatids

Meiosis 1 & 2 Vocabulary Words Somatic: body cells Gametes (germ cells): sex cells Autosomes: chromosomes that contain genes for characteristics not directly related to the sex of an organism Sex Chromosomes: chromosomes that directly control sexual characteristics, X & Y (23 rd pair) XX = Girl XY = Boy Homologous: chromosomes that have a pair chromosome from the other parent Homologous: chromosomes that have a pair chromosome from the other parent ◦“homo” means same

Figure 10.3b Exchange of DNA during prophase I increases genetic variability. Chromatids are no longer exact duplicates. What is this called?!  Include a picture next to the definition!!

Journal Week 19- Thurs 1/22 J-copy the question and the complete correct answer ◦Crossing over contributes to the recombination of genetic material in offspring. When does crossing over happen during meiosis? ◦(a) when the DNA of the diploid cell is copied ◦(b) when homologous chromosomes move to opposite ends of the dividing cell ◦(c) when spindle fibers move the chromosomes toward the midline of the dividing cell ◦(d) When homologous chromosome pair and portions of chromatids break off and are exchanged TI- none CW- Phases of Meiosis, Meiosis Power Notes & Reinforcement HW- Interactive reader pgs (highlight & answer) DUE Fri 1/23, Meiosis Quiz Mon 1/26

Meiosis 1: Division of Diploid Cell & Homologous Chromosomes, 2 “N” Cells Steps Steps: ◦Interphase I  DNA Replicates, Cell Grows ◦Prophase I  Chromosomes pair (Tetrad)  Spindles & Centrioles form  Nucleus dissolves  Crossing Over ◦Metaphase I  Homologous pairs line up in middle of cell  Spindles attach to centromeres ◦Anaphase I  Homologous pairs separate ◦Telophase & Cytokinesis I  New nuclei form around chromosomes  Cytoplasm divides

Meiosis I: Homologous Chromosomes Separate What is this process called? Color as show and these on the bottom of the page

Meiosis 2: Separating the Sister Chromatids, 4 “N” unique cells Steps of Meiosis II: ◦Prophase II  2 haploid (N) daughter cells  No DNA Replication ◦Metaphase II  Chromosomes line up in the middle of the cell ◦Anaphase II  Sister chromatids separate ◦Telophase & Cytokinesis II  Results in 4 haploid (N) unique daughter cells

Meiosis II: Sister Chromatids Separate Color as show and these on the bottom of the page

Meiosis I & II

Check for understanding 1. What phase directly follows metaphase I? 2. How many cells are present at the end of meiosis I ? 3. A cell has a diploid number of 60, what is the organism's haploid number? 4. Meiosis occurs in what type of cells? 5. In what phase do homologous chromosomes pair up and crossing-over can occur? 6. In what phase do the CHROMATIDS separate? anaphase I 2 30 gametes prophase 1 anaphase 2

7. Identify the phase:8. Identify the phase: anaphase 1 anaphase 2

Pg 180 Which of these pictures is metaphase I of MEIOSIS and which is metaphase of MITOSIS? Mitosis Meiosis

Week 19 Journal- Fri 1/23 Compare & Contrast Mitosis & Meiosis: Create this chart in journal Mitosis Meiosis Phrases to Compare: 1) Reproduction for sex cells 2) Contain “full” chromosome number (EX: 46) 3) Reproduction for body cells 4) Found only in reproductive organs 5) Examples of sex cells: (sperm & egg) 6) Asexual 7) Found in every cells of the body except sex cells 8) Sexual 9) Examples of Body Cells (muscle cells skin cells, bone cells) 10) Number of stages? (Interphase, PMAT, Cytokinesis) 11) Number of divisions (1 or 2) 12) 4 Haploid Cells Made 13) 2 Diploid Cells Made 14) Identical Daughter Cells Made 15) Unique Cells Made

Check Your Answers & make corrections! Mitosis ◦Contain “full” chromosome number (EX: 46) ◦Reproduction for body cells ◦Asexual ◦Found in every cells of the body except sex cells ◦Examples of Body Cells (muscle cells skin cells, bone cells) ◦6 Stages ◦1 Division ◦2 Diploid Cells Made ◦Identical Daughter Cells Made Meiosis I & II ◦Reproduction for sex cells ◦Found only in reproductive organs ◦Examples of sex cells: (sperm & egg) ◦Sexual ◦6 Stages ◦2 Divisions ◦4 Haploid Cells Made ◦Unique Cells Made

Journal Week 19- Fri 1/23 J- Compare & Contrast Meiosis & Mitosis T Chart TI- Interactive reader pgs (highlight & answer) CW- Genetic Variation, Meiosis Animation & Review Questions, Concept Check HW- Meiosis Quiz Mon 1/26, Mitosis Vs Meiosis Wkst DUE Mon 1/26

Concept Check Meiosis results in _____ a.2 haploid daughter cells b.4 haploid daughter cells c.2 diploid daughter cells d.4 diploid daughter cells 2. Which of the following cells undergo meiosis? a. sperm cells b.liver cells c.unicellular organisms d.all of these 3. The picture depicts what phase of meiosis a.prophase 1 b.prophase 2 c.anaphase 1 d.anaphase 2

Concept Check 1. Crossing-over occurs during: a.anaphase 1 b.metaphase 1 c.prophase 1 d.prophase 2 2. A cell with a diploid number of 24 undergoes meiosis, how many chromosomes are in each daughter cell? a.6 b.12 c.24 d.48

Concept Check

Journal Week 20- Mon 1/26 J- Identify the missing name of phases TI- Mitosis Vs Meiosis Wkst CW- Phases of Meiosis Pieces Sorting Activity, Meiosis Quiz (50 pts) HW-none Name of PhaseDescription 1.Homologous chromosomes pair up and form tetrad 2.Spindle fibers move homologous chromosomes to opposite sides 3. Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed 4.Chromosomes line up along equator, not in homologous pairs 5.Crossing-over occurs 6.Chromatids separate 7.Homologs line up alone equator 8.Cytoplasm divides, 2 daughter cells are formed