November 13 Lecture Notes

November 13 Lecture Notes - Lecture(3 for class(Material...

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Lecture (3) for class November 13, 2006 (Material that will be on the final exam) Lecture review- Tuesday 3 30, 500 Office hours – Tuesday 1 40- 300 Thursday 3 30- 500 Dr. Martin’s Lectures…. Man…. Just remember that this week you will have a quiz on both of the labs. Not just one. We are going to talk about Genetics But first we have to get into Meiosis. Transmission genetics (Patterns by which genes are transmitted from one generation to the next) Karyotype- is just a representation of any individual’s genetics composition (chromosomes) First thing that is done is that the homologous chromosomes are paired together… the way we know that they are homologous chromosomes is by looking at the size, the centromeres, or the pattern of bands that show up with the staining solution. Humans have 46 chromosomes; this means there are 23 pairs… For each pair, there are Maternal and Paternal chromosome. One from the father and the other form the mother. However, there are 22 pairs of chromosomes that are known as autosomes. These 22 are not sex-linked. There is one pair that is. .. they are known as the X and Y chromosomes. X Y means a Male… Now during meiosis you start off with a diploid cell and end up with 4 haploid cells. An individual with N=5 means that there are 10 chromosomes and 5 pairs. There are two cell divisions. The 4 cells that are produced have only one representative form each homologous pair and it is unduplicated. It does it in such a way that you only get either the paternal or the maternal part of original chromosomes. In a sexual lifecycle… the fusion of gametes is what makes it sexual. The gametes have to be haploid so that they can make a diploid zygote or cells. Just remember that But remember that meiosis in plants only makes spores, not directly into gametes. In humans, however, the product of meiosis is Gametes along with many other animals. Phases of Meiosis- Before mitosis starts there is interphase…
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Phases in interphase are… G1 and then S and the G2. This is known as Premeiotic Interphase. 1. S-phase is known as the premeiotic interphase. = the chromosomes are being duplicated. Meiosis I- (Prophase is the first phase of mitosis ) but also in Meiosis there is Prophase I … (must indicate with the roman numerals which phase it is in meiosis) Prophase I Metaphase I Anaphase I Telophase I What happens here before the next stage, the chromosomes happen to go into a state where they look as though they are in a interphase state. A true interphase has an S-phase, but this one doesn’t have an s-phase. .. so this stage that is between Meiosis I and meiosis II is Interkinesis (no s-phase and also some organisms skip this)
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This note was uploaded on 04/04/2008 for the course BIO 101 taught by Professor Martin during the Fall '08 term at Rutgers.

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November 13 Lecture Notes - Lecture(3 for class(Material...

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