Cell Division, cell cycle, meiosis, mitosis
Order by
39 terms
Terms | Definitions |
|---|---|
 Cell Division | -Growth in most multi-cellular organisms, increase in cell number -Specialized cells have limited life spans, must be replaced. -Proliferation of cells through cell division |
| Mitosis | the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei. It is generally followed immediately by cytokinesis. |
| Types of cells for mitosis | Somatic or body cells |
| Karyokinesis | process of nuclear division. aka mitosis |
| Cytokinesis | Division of cytoplasm where a single eukaryotic cell is divided to form two daughter cells. |
| Interphase- Mitosis | -Not resting phase -Process of synthesizing DNA -Structures during interphase Nuclear envelope, nucleolus, dispersed chromatin material, cytoplasm, centrioles, -chromosomes during interphase are too uncoiled to be visible. Before prophase the chromosomes replicate |
| Prophase-Mitosis | -Chromosomes become visible (short and thick). -Nucleolus will diminish in size and disappear. -Centrioles undergo reduplication then migrate to opposite poles of nucleus -nuclear membrane begins to break down and disappear |
| Metaphase-Mitosis | -Begins with the appearance of spindle fibers -Chromosomes gather in center along equatorial plate *Two types of fibers occur Continuous and Chromosomal |
| Continuous vs Chromosomal Fiber | Seen in Metaphase of Mitosis -Continuous runs pole to pole -Chromosomal runs from the pole to the centromere (1) of the chromosome |
| Centromere AKA ? | Kinetochore -Side note- centromeres usually contain DNA |
| Anaphase-Mitosis | 1. doubling of the centromere (initial step) 2. separation of chromatids from each chromosome 3. Cleavage furrow starts to appear |
| Whats the initial step of anaphase in mitosis | Centromere doubles |
| Telophase- Mitosis | 1. Cleavage furrows continue 2. Nuclear membrane reforms 3.Chromosome again uncoils and becomes indistinct 4. Nucleolus reforms 5. At the end of telophase there are two daughter cells with identical chromosomes of the parents |
| Mitosis Phases in order | Interphase, Prophase, Metaphase, Anaphase, Telephase IPMAT |
| Cell Cycle | Tissues culture---Cells undergo rapid growth and division. -Constant doubling time is cell cycle -Biochemical and morphological events repeat |
| Biochemical Events | -Separation of the double helix of chromosomes and replication of each. -Known as a semi conservative replication. -Must keep constant number of chromosomes -Parent chromosome goes to two new chromosomes consisting of the parent and a new synthesized chromosome. |
| S Phase | 1.Period of active DNA synthesis 2. Lasts 6-8 hours 3. 30-40% of cycle |
| G1 Phase | 1. Period of active RNA and protein synthesis 2. Both the nucleus and cytoplasm of daughter cells enlarge 3. 30-40% of cycle |
| G2 Phase | 1. Period in which there is no DNA synthesis 2. Both other preparations for division take place 3. 10-20% cycle |
| M Phase | 1. Consists of those structural events which occur during mitosis.* 2. P/M/A/T g1 S and G2 all occur during INTERPHASE (NOT RESTING AT ALL) M Phase 2 divisions 1. Karyoknesis 2.Cytokinesis |
| Meiosis- Def | -Development of male and female reproductive cells. -Form of cell division |
| Meiosis- What happens in general | Two successive nuclear divisions with only one replication of the chromosomes, resulting in four daughter cells with 1/2 the chromosome numbers of the mother/father cell (haploid) |
| Meiosis first mitotic division | Reductional Division- Chromosome Number is reduced |
| Meiosis Second division | Equational division. |
| Importance of meiosis | -Constant chromosome number from generation to generation. Meiosis is characterized bu a very long prophase I which can be divided into 5 stages. |
| Lepotene | 1st of prophase I of meiosis -chromosomes are thin and threadlike -have beadlike structures- chromomeres function unknown |
| Zygotene | 2nd Part of prophase I meiosis -homologous chromosomes begin to pair (synapse) CROSSING OVER OCCURS PROPHASE 1 -paring continues throughout this phase** |
| Pachytene | 3rd part of prophase I meiosis -Shortening of the chromosomes- 1/4 the length -Theory- Precursors (DNA) are added -Pairing of chromosomes is completed |
| Diplotene | 4th and last part of prophase I meiosis -intimately paired chromosomes begin to repel each other and sererate. -During this stage, chromosomes do not completely seperate, they remain joined at a certain points where two of the 4 chromatids form an x crossing over one another -X points referred to as chiasmata (crossing over) exchange material** -nucleolus breaks down |
| Diakinesis | Chromosomes at max condensation Nuclear membrane breaks down |
| Metaphase I Meiosis | 1. Tetrads- chromosomes that have duplicated, therefore 4 tetrads (chromatids) line up along equator 2. Nuclear envelop disappears |
| Anaphase I Meiosis | Homologues seperate |
| Telophase I Meiosis | in some cells cytokinesis does not occur, so you end up with two nuclei in one cell- --does not happen in mammals |
| Interphase II | Interkinesis (no dna replication) |
| Prophase II | Spindles appear as nuclear membrane breaks down |
| Metaphase | Chromatids pairs of chromosome line up on the equator |
| Anaphase II | Centromeres duplicate and divide Chromatids of chromosomes separate and move to opposite poles |
| Telophase II | Spindles disappear nuclear membrane reappears cell membrane furrow forms four cells result in haploid* |
| Mitosis VS Miosis | Mitosis- 2C-4C-2C Meosis 2C-4C-2C-1C |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.