Build a STRUCTURAL concept map of has part starting with cell cycle and using all of the following: Metaphase Prophase Interphase Cell division phase Telophase S phase G1 phase G2 phase Anaphase Cytokinesis Mitosis
Cell Differentiation and Meiosis Study guide Compare the processes and products of meiosis I and meiosis II. Compare the overall processes and products of meiosis and mitosis. Explain how independent assortment of chromosomes during meiosis, and crossing over contribute to genetic diversity in offspring. Explain what makes the many types of adult human cells different. Explain how every cell has the potential to act like every other cell. Compare the properties of embryonic and adult stem cells. Explain the advantages and disadvantages of using adult stem cells to produce replacement tissues.
A pancreas cell, eye cell and nerve cell in your body: Are these cells duplicates of the original cell (zygote)? Are these cells genetically identically to each other (same number and type of chromosomes)? Does a eye cell have the gene to make insulin? Why are they different in form and function?
Most cells in an adult body are differentiated Differentiated cells are specialized in form and function Differentiated cells have a particular pattern of genes that are expressed and not expressed How do cells become specialized?
Cell differentiation occurs during the embryo development Early cells are not differentiated (Stem Cells) during development cells become more specialized (differentiated) by getting some genes activated and some others inactivated NOTE: Not all stem cells have the same level of stemness
Stem cells are found in the embryo and adult but vary in their stemness
Totipotent cells can give rise to an entire human
Why is studying stem cells useful?
Stem Cell Therapy: embryonic stem cells vs. adults stem cells How does their potential as therapy vary? What are the ethical considerations? Special considerations of both?
Generating stem cells that are genetically identical to a patient through therapeutic cloning
Generating stem cells that are genetically identical to a patient through ips cells ips cells are much less expensive to create than ES cells generated through therapeutic cloning However, because the "reprogramming" process introduces genetic modifications, the safety of using ips cells in patients is uncertain.
Human Life Cycle: mitosis for development and meiosis for reproduction
Humans have chromosomes in each cell What pattern do you notice in the human karyotype (a technique that organizes chromosomes by type and size)?
Two chromosomes that carry the same genes are called homologous chromosomes In a homologous pair : One of the chromosomes was inherited from father One of the chromosomes was inherited from mother In a homologous pair: both chromosomes have the same genes, but are not necessarily identical (they might be different versions, different sequence of bases)
Pretend Cell How many chromosomes does this cell have? How many types of chromosomes does this cell have? (note size of chromosomes) Does this cell have homologous pairs of chromosomes? How many pairs? Has this cell been through the S phase?
Diploid cells and Haploid cells Diploid cell: symbol (2n) has two sets of chromosomes has PAIRS of HOMOLOGOUS chromosomes all somatic cells are diploid HAPLOID cells: symbol (n) has one set of chromosomes has only one of each kind Gametes are haploid
Is this cell haploid or diploid?
What about this cell? Chromosome Homologous pair of chromosomes
Gametes are produced by a different type of cell division called meiosis # of cells produced # of chromosomes in daughter cells vs. parent cell One (diploid) mother cell 4 (haploid) daughter cells
Meiosis I produces cells, each of which is. 1. two... identical to the other 2. two... haploid 3. two... diploid 4. four... haploid 5. four... diploid Meiosis II produces cells, each of which is. 1. two... diploid 2. two... haploid 3. four... identical to the other 4. four... haploid 5. four... diploid
Table comparing the stages of meiosis STAGES OF MEIOSIS HOW ARE THE CHROMOSOMES ARRANGED DURING METAPHASE? WHAT SEPARATES DURING ANAPHASE? DOES CROSSING OVER TAKE PLACE? DOES INDEPENDENT ARRANGEMENT TAKE PLACE? ARE CELLs HAPLOID OR DIPLOID ATH THE END OF THIS STAGE? Meiosis I Meiosis II
Meiosis 1: homologous chromosomes separate Prophase 1: homologous chromosomes pair up (crossing over can occur) Metaphase 1: homologous pairs line up in the middle (randomly) note: double file Anaphase 1: homologous chromosomes separate Result of meiosis 1: two haploid cells, each chromosome has two chromatids
Meiosis II: sister chromatids separate Metaphase 2: chromosomes line up in the middle Anaphase 2: Chromatids separate (note: single file) Result of Meiosis II: four haploid daughter cells
I.D. each one of these phases Homologous chromosomes migrate to opposite poles during. 1. prophase II 2. telophase II and cytokinesis 3. anaphase I 4. metaphase II 5. metaphase I
Accidents during meiosis can alter chromosome number in gametes Cause: Non disjunction the chromosomes in a pair of chromosomes or sister chromatids fail to move apart properly Result: gametes have an extra or a one less chromosome
An extra copy of chromosome 21 causes Down Syndrome
Mitosis vs Meiosis Mitosis Meiosis Number of DNA replication events before division Number of cytokinesis events Number of daughter cell produced Number of sets of chromosomes in daughter cells Compared to original cell Purpose in humans