BIOL 1201 Learning Objectives Exam 4 Fall 2013 Chapter 12 Cell Cycle Know how daughter cells produced by mitosis are different than daughter cells produced by meiosis Mitosis produces 2 daughter cells that are identical to each other as well as the parent cell Meiosis I and II will produce 4 daughter cells that are NOT identical to each other or the parent cell Understand how somatic cells are different than gametes Somatic cells are normal body cells They are DIPLOID 46 in humans Gametes are your sex cells sperm and egg They are HAPLOID 23 in humans Know what process produces sister chromatids where they are attached to other and what role they play in mitosis DNA replication during the S phase of interphase produces them They are attached to each other at the centromere And one chromatid from each pair of sister chromatids ends up in each of the daughter cells produced by mitosis Be able to list what happens during the different stages of the cell cycle Interphase o G1 phase cell grows o S phase DNA replicates o G2 phase cell grows some more M phase o Mitosis division of nucleus o Cytokinesis division of cytoplasm Have a general understanding of what occurs during the 5 stages of mitosis Prophase prometaphase nuclear envelope breaks down Chromosomes condense Mitotic spindle begins to form Metaphase sister chromatids line up att the metaphase plate equator of cell facing opposite directions Anaphase sister chromatids separate and get pulled to opposite poles of the cell Cell elongates Telophase Cytokinesis Cleavage furrow forms in animal cells cell plate forms in plant cells Cytoplasm splits Nuclear envelope re forms And daughter cells are produced Understand the role of the mitotic spindle microtubules and kinetochores during mitosis Mitotic spindle similar to a spool of a kite string Physically separates chromosomes Microtubules similar to the actual string Attach to the chromosomes and the spindle and separates the chromosomes Kinetochores like handles on the chromosomes Located next to the centromeres and this is the attachment point for the microtubules Understand what type of offspring are produced by binary fission Form of asexual reproduction in some prokaryotes Produces offspring that genetically identical to the parent cell Produces very little variation in offspring Know where each checkpoint occurs during the cell cycle and what types of proteins control each checkpoint G1 checkpoint occurs just before the S phase of interphase G2 checkpoint occurs after S phase before the M phase of interphase M checkpoint occurs just before cytokinesis in the M phase of the cell cycle Cyclins and Cyclin Dependent Kinases CDKs control each checkpoint Chapter 13 Meiosis and Sexual Life Cycles Understand how sexual and asexual reproduction differ from each other Sexual reproduction produces offspring that are genetically different from the parent cell Asexual reproduction produces offspring that are genetically identical to the parent cell Understand what a karyotype would look like in both somatic cells and gametes In somatic cells there would be 22 pairs of autosomes and one pair of sex chromosomes XX in females XY in males In gametes there would be 22 autosomes and one sex chromosome always an X in female gametes eggs could be X or a Y in males sperm Understand the relationship between homologous chromosomes and how they differ from sister chromatids Homologous chromosomes are the same length and contain the same genes that control the same characteristics Within each pair of homologous chromosomes one chromosome came from mom and one came from dad While these chromosomes contain the same genes they are NOT identical Sister chromatids are IDENTICAL copes of individual chromosomes they are produced during the S phase of the cell cycle in which chromosomes are replicated Know how many autosomes and sex chromosomes are present in human somatic cells and gametes Somatic cells 44 autosomes 2 sex chromosomes Gametes 22 autosomes 1 sex chromosomes Understand diploid and haploid chromosome numbers Diploid 2 VERSIONS of each chromosome mom s version and dad s version So you have homologous chromosome PAIRS Haploid only have 1 VERSION of each chromosome either mom s or dad s version but not both No homologous chromosome pairs Understand what happens at each stage of Meiosis I and Meiosis II including which chromosomes separate and what type of daughters cells are present at the end of each division Meiosis I o Prophase 1 homologous chromosome pairs and their sister chromatids begin to associate with each other Forms a TETRAD Sister chromatids are attached at the centromere Homologous chromosomes make contact with each other at the CHIASMATA This is called crossing over o Metaphase 1 homologous chromosomes pairs line up at the metaphase plate o Anaphase 1 homologous chromosome in pairs separate while sister chromatids remain attached o Telephase Cytokinesis parent cell divides to produce 2 HAPLOID daughter cells that each contain ONE chromosome from each homologous pair as well as copy sister chromatid still attached Meiosis II o Identical to mitosis o Sister chromatids separate during anaphase just like in mitosis and both daughter cells divide to produce FOUR daughter cells that are all HAPLOID And because of crossing over all of these daughter cells are genetically unique Understand the process of crossing over when it occurs and what it results in Happens during prophase I and meiosis I NON SISTER chromatids make contact with each other forming the CHIASMATA and exchanging genetic information Produces entirely unique chromosomes resulting in more variation in the offspring during sexual reproduction Understand which division is reductional and which division is equational and why Reductional means that the number of chromosomes is reduced This is meiosis I because cell divides to produce 2 haploid cells Equational means the number of chromosomes doesn t change This is meiosis II because 2 haploid parent cells divide to produce 4 haploid daughter cells Chapter 11 Cell Communication Understand the different mechanisms for long distance and short distance signaling Long distance signaling will involves hormones entering the blood stream Short distance signaling can involve cell to cell junctions gap junctions in animal cells plasmodesmata in plant cells cell to cell contact Paracrine signaling chemical signaling between cells very close to each other Synaptic signaling paracrine signaling
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