Week 6 DNA RNA Chromosomes September 23 2013 DNA Deoxyribonucleic Acid o Major component of chromosomes o DNA is found in nucleus in every cell o Two complimentary strands of DNA form a double helix o Sugar phosphate and a nucleotide ATGC over and over again o Nucleotides Base unit that makes up all DNA Consists of Sugar Deoxyribose Phosphate Phosphate Base 1 of 4 DNA bases o Adenine o Cytosine o Guanine o Thymine ine is nitrogen base Normally o A with T has 2 hydrogen bonds o C with G has 3 hydrogen bonds RNA Ribonucleic Acid o Has 1 more oxygen in it than DNA o Not a permanent molecule and only exists for the time it is needed then broken apart o RNA is found as a single strand and the strand is generally in a straight or linear configuration o RNA is found ALL throughout the cell o Three basic classes mRNA Messenger RNA tRNA Transfer RNA rRNA Ribosomal RNA Each has a specific function 1 Sends messages to and from 2 Transfers things 3 Forms a Ribosome o RNA is made of individual nucleotides Sugar Ribose Phosphate Phosphate Base 1 of 4 RNA bases o Adenine o Cytosine o Guanine o Uracil Normally A with U C with G Chromosomes o Composed of DNA and protein o Located in nucleus and contains genetic material Proteins Histones DNA wraps around the Histones September 25 2013 Maternal Chromosome parent Paternal Chromosome parent o Any chromosome that was contributed to the offspring by the female o Any chromosome that was contributed to the offspring by the male o Paternity Test looks at one cell s chromosomes and exposes it to a restriction enzyme It chops the DNA and spread them out Check mother s DNA with child s and then see which parts the mom contributed to the child Then check father s set of DNA and see if it matches the child s Diploid o 2 sets of chromosomes o One maternal and one paternal o Diploid occurs in ALL cells except the gametes o Human diploid number is 46 Haploid o 1 set of chromosomes o Only occurs in GAMETES o Human haploid number is 23 Polyploidy o Many sets of chromosomes Tetraploid 4 sets of chromosomes wheat o An onion has 5 times more DNA than a human does Homologous chromosomes o Chromosomes that carry the same genes and are a matched pair One maternal and one paternal They are always the same size and same shape Except one pair in males Genes o Stretch of DNA that encodes for a specific trait o Generally One gene One protein Gene Locus o The physical location of a gene on a chromosome Gene location o Human Genome Project Dominant Genes o A gene that when present will be expressed in an individual o Brown eyes o Sickle cell anemia o A gene that will only be expressed if it occurs on BOTH of the homologous chromosomes Recessive Genes o Blue eyes Alleles o The DNA code which may be different for the same gene o Gene hair color o Allele brown black white red blonde o Gene eye color o Allele blue brown hazel green September 27 2013 Inheritance o Autosomal Chromosomes o Sex Chromosomes o Homozygous autosomal when two alleles on homologous chromosomes are the same RR or rr o Heterozygous sex when two alleles on homologous chromosomes are different Rr o Punnett Square simple grid used to record possible genetic makeup Genotype Phenotype traits the individual has actual alleles an individual carries expression of the alleles an individual carries the o Incomplete Dominance Occurs when heterozygous genes are both expressed Red and white flowers make PINKISH flowers