Module+6+Review


 * For this Module Exam, please use the cognitive objectives for your review guide. **

** COGNITIVE OBJECTIVES: ** Upon completion of this module the student will be able to:

LYNNE = __Chapter 9__: = 1. Distinguish between somatic cells and germ cells. // Somatic cells: // Body cells -Diploid // Germ cells: // animal cell that can undergo meiosis and give rise to gametes- haploid

2. Define the terms //chromatin, chromosome, sister chromatids// and //centromere.//

**Chromatin**: All the DNA molecules unwound and mixed with their associated protein molecules **Sister Chromatids**: The two attached DNA molecules of a duplicated chromosome **Centromere**: A small region on a chromosome where a DNA remains connected to an identical copy 3. Describe the cell cycle. Name the stages and describe the key events that occur in each stage.
 * Chromosome: ** One DNA molecule with attached proteins


 * Interphase** is the part of the cell cycle when the cell is carrying out the normal functions of the cell and prior to cell division it increases in size, forms additional organelles and copies the DNA.

=
// How much of the cell cycle is devoted to mitosis? //** I don't really understand what this is asking... I think it depends on what type of cell and how often it divides. But, I would say that it is mostly in Interphase until it is ready to divide, then it just does it quickly and goes on being a cell (not a very scientific answer). ** =====

4. Explain briefly the significance of mitosis in the life of a cell. List its four main stages and describe in detail the key events and structures involved in each stage. // Use this space to draw out the phases of mitosis and DESCRIBE in words what is going on, using as many vocabulary words as possible. Try to avoid using "plain English” and try and stick to the biological vocabulary you have learned as much as possible. // Mitosis is divided into four stages: (PMAT) **Prophase:** The DNA (chromatin) condenses into distinct, “threadlike”strands clearly visible under a light microscope **Metaphase**: Some of the spindle microtubules pull some of the chromosomes toward one side of the cell while others pull some of the chromosomes toward the other side of the cell until they all line up in the middle of the cell. **Anaphase:** The spidle microtubles pull the sister chromatids apart and bring to the edge of the cell toward the centrioles. **Telaphase:** The spindle microtubules dissolve, the nuclear membrane reforms around each cluster of chromosomes so two nuclei are forming, Chromatids begin to uncoil and become more diffuse.

5. Briefly compare the process of cytokinesis (cytoplasmic division) in plant and animal cells.

===Cytokenisis or the splitting of the cytoplasm begins as the nuclear membrane is forming. In animal cells, the cell membrane begins to pull inward forming an hour glass or figure 8 appearance. In plant cells a dark line begins to form between the two nuclei that are forming. In plant cells, they multiply in one direction which makes the plant grow in that direction. ===

=-- Melissa=

__Chapter 10__:
1. Distinguish between //asexual// and //sexual// reproduction. Explain the major biological advantages of sexual reproduction. // asexual : // Any reproductive mode by which offspring arise from one parent and inherit that parent's genes only.

// sexual: // Production of genetically variable offspring by gamete formation and fertilization. The advantages of sexual reproduction are increasing the genetic diversity and the rate of evolution.

2. Distinguish between the terms //gene// and //allele.// __Gene__: Heritable unit of information in DNA. __Allele__: One of two or more forms of a gene; alleles arise by mutation and encode slightly different versions of the same gene product.

3. Describe homologous chromosomes. Where do they come from? <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">They come from body cells of diploid organisms. They are members of a pair of chromosomes with the same length, size, and genes.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">4. State the //diploid number// and //haploid number// for humans. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; tab-stops: .25in;">n=23. Having one of each type of chromosome. A human gamete is haploid. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; tab-stops: .25in;">2n=42. Having two of each type of chromosome characteristics of the species.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">// 5. //Describe the key events and stages of Meiosis I and Meiosis II. // Please use your biological vocabulary! // <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">Meiosis I: <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">Each duplicated chromosome lines up with its partner. Then the two move apart, toward opposite spindle poles. <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">During __Prophase I,__ chromosomes condense and align with their homologues which undergo crossing over. The bipolar spindle forms, while one of two pairs of centrioloes is moved to the other side of the nucleus. The envelope breaks up, and microtubles attach to one of the chromosome pairs. <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">During __Metaphase I__, All pairs of chromosomes are at the spindle. <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">During __Anaphase I__, a bunch of duplicated chromosomes are nearing each spindle pole. <span style="font-family: times new roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; msoaddspace: auto; msobidifontstyle: normal; msolist: l2 level1 lfo2; tab-stops: .25in; tabstops: .25in; text-indent: -0.25in;">During __Telophase I,__ two nuclei form, all the chromosomes are still duplicated, and each still has two sister chromatids. Meiosis II: The chromosomes condense in prophase II and align in metaphase II. Sister chromatids of each chromosome are pulled away from each other in anaphase II, so that each becomes an individual chromosome. By the end of telophase II, there are four haploid nuclei, each with one set of chromosomes. The chromosomes are unduplicatred at this time. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">6. Explain what is meant by “crossing over” and when does it occur during the process of Meiosis. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">The non-sister chromatids undergo //crossing over// during prophase I: They trade segments at the same location along their length, so that each gets new alleles that were not present before in either parental chromosome.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">7. Explain how random fertilization, independent assortment, and crossing over contribute to genetic diversity. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.5in; mso-add-space: auto; mso-list: l2 level1 lfo2; tab-stops: .25in; text-indent: -0.25in;">These processes contribute to genetic diversity by contributing to the variation that we see among offspring of sexual reproducers.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">8. Compare and contrast the overall process of mitosis and meiosis in terms of the type of cells each occurs in, the number of chromosomes present at the beginning and end of each process, the number of daughter cells produced, and are the daughters identical to each other or not. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Mitosis: <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Occurs in all eukaryotic cells, <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Number of chromosomes present at beginning: 1 At end: 2 <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Number of daughter cells produced: 2 <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Are daughters identical or not?: Theay are identical because they are diploid and somatic. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Meiosis: <span style="font-family: "Times New Roman",Times,serif;">Occurs in all eukaryotes (including single-celled organisms) that reproduce sexually. <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Number chromosomes present at beginning: 46 At end: 23 <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Number of daughter cells produced: 23 <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">Are daughters identical or not?: They are genetically different, so not identical.

=--- Martha=

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in list .5in; text-indent: -0.25in;">__Chapter 11__:
<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">1. Briefly discuss the significance of Mendel’s work to the field of genetics. through cross pollination he studied traits that appear in pea plants <span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">2. Define the term // gene.heritable unit of information in DNA, occupies a particular location on a chromosome. //

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">3. Define and distinguish between these groups of terms: //“true-breeding” organisms// and //hybrids; P, F1,// and //F2 generations; genotype// and //phenotype; dominant// and //recessive; heterozygous// and //homozygous.// // What is a true breeding organism?excluding rare mutations, all offspring have the same form of the trait as the parent(s), generation after generation. //

// P generation:parent(s) // // F1 first generation of offspring (children) // // F2 second generation of offspring (grandchildren) // // genotype the particular type of alleles that an individual carries // // phenotype the individuals traits // // dominant genotype: (let’s say for pea plants PP, Pp) considered dominant if its effect masks the effect of a recessive allele paired with it // // recessive genotype: (let’s say for pea plants pp) able to have its' effects masked by, or hidden, by a dominant // // heterozygous:An individual with nonidentical alleles of a gene // // homozygous:an individual with identical alleles of a gene //

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 31.5pt; mso-add-space: auto; mso-list: l0 level1 lfo3; tab-stops: .25in; text-indent: -0.25in;">4. Predict the phenotypic and genotypic outcome of a simple monohybrid cross. // Do all the combinations you can think of with a monohybrid cross to the F2 generation to make sure you see all the patterns. //

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">5. Describe the process of running a “//testcross//” to determine an unknown genotype. a method of determining genotype. An individual of unknown genotype is crossed with one that is known to be homozygous (having identical alleles )recessive. The traits of the offspring may indicated that the individual is heterozygous(non identical alleles) or homozygous(identical alleles) for a dominant trait.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 31.5pt; mso-add-space: auto; mso-list: l0 level1 lfo3; tab-stops: .25in; text-indent: -0.25in;">5. Explain Mendel’s theories of “//segregation//” and “//independent assortment//”. // I discussed this on Elluminate, watch the recording to hear about it in detail. diploid cells have pairs of genes, on pairs of homologous (identical alleles) chromosomes. The two genes or each pair are separated from each other during meiosis ( the nuclear division process that halves the chromosome number, in the haploid // (having one of each type of chromosome characteristic of the species) number. This is the basis of sexual reproduction.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 31.5pt; mso-list: l0 level1 lfo3; tab-stops: 0in .25in; text-indent: -0.25in;">6. Explain the concepts of //incomplete dominance// and //codominance// as they relate to gene expression. // Cite the examples from your text of each of these phenomena. // // Incomplete dominance:one allele of a pair is not fully dominant over its partner, so the heterozygote's phenotype is somewhere between the two homoaygotes //

// Codominance:two nonidentical alleles of a gene are both fully expressed in hererozygotes, so neither is dominant or recessive. //

// __ Also, epistasis:typically one gene product suppresses the effect of another __ //

// __ Pleiotropy: when one gene influences multiple traits __ //

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">__Chapter 12__:
<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">**Lynne** 1. Distinguish between //autosomes// and //sex chromosomes//. State the sex chromosome difference for human males and females.

<span style="font-family: Times New Roman; margin: 6pt 0in 0pt 0.25in; tab-stops: .25in; text-indent: -0.25in;">**Melissa** 2. Describe the process of karyotyping. // Don’t forget to do the lab on this and hand it in on Tuesday. // **Martha** 3. Describe the changes in chromosome structure that result due to duplication, inversion, translocation, deletion, and non-disjunction “errors” that occur in meiosis. Duplication: normal chromosomes that have DNA sequences that are repeated two or more times. Deletion: the loss of some portion of a chromosome. Inversion: Part of the sequence of DNA within the chromosome becomes oriented in the reverse direction, with no molecular loss Translocation: If a chromosome breaks, the broken part may bet attached to a different chromosome, or to a different part of the same one. Non-disjunction: in which one or more pairs of chromosomes do not separate properly during mitosis or meiosis. Nondisjunction affects the chromosome number at fertilization.