PPT-Sex Chromosomes

Chapter 5 1 Outline Sex chromosomes Sex determination 2 3 Role of Y Chromosome Klinefelter and Turner Syndromes XXY XO 47 XXX Syndrome Also called triploidX or . Chromosome theory of inheritance. Genes located on chromosomes = gene locus. Thomas Hunt Morgan, Columbia Univ. “Fly room”. Drosophila. 100s of offspring. 2n = 8. 3 . prs. autosomes. X and Y sex chromosomes. 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. .. Genes. for these . traits. are located . only. on the . X. chromosome (NOT on the Y chromosome). X linked alleles . always. show up in . males. whether . dominant. or . recessive. because males have only . 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.. Boa. and . Python. Gamble et al. 2017. Boa imperator. AKA the Central American Boa Constrictor. AKA the Colombian Boa Constrictor. Actually spans Central and South America. Stunning really. Known to produce offspring via facultative parthenogenesis. Environmental Influence,. Sex-Linked Traits. In this presentation. Slides 3-4: . Punnett. Square. Slide 5-7: Co-Dominance and Blood-typing. Slide 8: Incomplete Dominance. Slide 9: Sex Linked Traits (X-Linked Traits). 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. Advanced Higher Biology. Miss A Aitken. How do we become male or female?. Genes (most common). Sex can be determined by genetic factors. Environment (less common). Sex can be determined by things going on in the environment. Human Genes and Chromosomes. Chromosomes 21 and 22 are the smallest human autosomes. Chromosome 22 has about 43 million DNA base pairs. Chromosome 21 has about 32 million base pairs. . Chromosome 22 has about 545 different genes. Genetic disorders tat occur on chromosome 22 are leukemia and neurofibromatosis (a tumor causing disease). There is also a long stretch of repeating DNA that does not code for proteins. . 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 . 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 . Sex Determination. Xy =. . XX= . female. male. Female . karyotype. Male . karyotype. X and Y chromosomes. Who decides. ?. Mom can give X . Dad can give X or Y.