PPT-CHROMOSOMES &

CELL DIVISION TOPIC 2 2015 CHROMOSOMES amp CELL DIVISION Things to cover Chromosomes Karyotypes inc chromosomal disorders Cell division Mitosis Meiosis amp fertilisation. Essential idea: Chromosomes carry genes in a linear sequence that is shared by members of a species.. The . asian. rice (. Oryza. sativa. ) genome can be seen illustrated . above. . Rice possesses up 63,000 genes divided up between 12 chromosomes. Chromosomes carry genes in a linear sequence that is shared by members of a species.. Understandings:. Prokaryotes have one chromosome consisting of a circular DNA molecule. . Some prokaryotes also have plasmids but eukaryotes do not. .. The Chromosome Theory of Heredity. Mutations. Regulation of Gene Expression. Objectives. State the chromosome theory of heredity. Explain how gene linkage affects inherited traits. Describe the process of crossing-over and explain how it increases genetic variety. diploid. Sex cells (gametes/germ cells) have only one set of chromosomes . . = . haploid. . That means when fertilization . occurs, the new individual will. have the correct number of chromosomes.. 1. 2 . 4. 8 . How many chromosomes are in the middle cell?. 1. 2 . 4. 8 . At what part of the cell cycle would you see a chromosome that looks like this. ?. G. 1. G. 2. . M. S . At what part of the cell cycle would you see a chromosome that looks like this? . Chromosomes carry genetic information. Chromosomes are wound up DNA. Diploid – Every body cell has 2 sets of chromosomes . n = number of chromosomes. Normal body cells have 2n (2 x n) chromosomes. Chromosomes carry genetic information. Chromosomes are wound up DNA. Diploid – Every body cell has 2 sets of chromosomes . n = number of chromosomes. Normal body cells have 2n (2 x n) chromosomes. Human Inheritance. Disorders caused by individual genes - dominant. Individuals with the disorder only need 1 allele to have the disorder. Huntington’s Disease. Caused by a repeat of the sequence CAG . 3.2.1. . Bacterial Chromosomes (prokaryotes). Most only have 1 chromosome.. Which means, it only contains a single copy of each gene (except during cell division when chromosomes are replicated).. Has circular DNA that contains all genes needed for basic life processes of the cell.. 22 pairs of autosomes. 1 pair of sex chromosomes. XX = Female, XY = Male. Karyotype - chromosomes are arranged according to shape and size. AN EXTRA COPY OF CHROMOSOME 21 CAUSES DOWN SYNDROME. This condition is called . Associate Professor and Head. Department of Sericulture. Yuvaraja’s College, . University of Mysore, Mysore, India. 11-Sep-20. 1. www.hbmahesh.weebly.com. CHROMOSOMES. The chromosomes are nuclear components of special organization, individuality and function. They are capable of self reproduction and play a vital role in heredity, mutation and evolution.. They are also called as mega chromosomes. . These chromosomes are very long and thick in appearance during metaphase than normal chromosomes.. Hence they are called as Giant chromosomes.. The Giant chromosomes are of two types-. Problems arose however regarding the following question:. Why are the number of alleles which undergo independent assortment greater than the number of chromosomes of an organism?. This was . explained by the . 1. What is contained within the nucleus?. 2. What is the job of the nucleus?. 3. What does our DNA control?. 4. What may happen if the DNA within a cell is disrupted?. Key Words. Nucleus. DNA. Chromosomes.