Genetics

• Deoxyribonucleic acid is a chemical that determines the physical characteristics of an organism. It is a code. DNA occurs in a long strand known as chromosomes.
• When the cell are not dividing, the DNA are in a from known as chromatin.
• Chromatin is a condensed form made up of DNA and proteins. The primary protein components are histones, which help organise the DNA into a bead-like structure known as a nucleosome, by providing a base for the DNA to wrap around.
• Chromatins are the least visible form of DNA found in the interphase stage
• DNA is found in a nucleus of a cell
• the observable characteristics of an organism are known as its phenotype.
• the phenotype is determined by the genotype and a mix of the environment
• Normal human cells are somatic cells
• somatic cells have 46 chromosomes.
• Gametes are sex cells
• gametes are for reproduction
• there are 23 chromosomes in Gamates
• Genotype is the allele combination of an organsim that determines the phenotype of an organism
• two alleles will give 3 different possible genotype outcome
• two alleles will give 2 possible phenotype outcome
• when the cells are dividing. the cells are in a form known as a chromatid.
• Chromatid is each copy of chromosomes resulting from DNA replication. Or just one half of a duplicated chromosome.
• The genetic code is a set of rules that dictates how information encoded in DNA or RNA is translated into proteins
• Each cell has its own jobs. Each cell type different roles in the body. There are over 200 different jobs
• The spiral side or backbone is made up of sugar molecules and phosephate group.
• The rungs are made up of nitrogenous bases.
• The rungs which are the sequences of bases are connected to the backbone through its bond with the sugar molecules
• At the lenght of DNA there are 4 letters sentences. In these sentences are 3 letter words known as codons. These words makeup a sentence that only the cell understand, these are known as your genes.
• Each sentence tells a cell to make a special molecule known as protein.
• Passing on characteristic from generation from generation is known as inheritance.
• The study of inheritance is a branch of biology known as genetics
• DNA replication is the process of which the DNA make another copy of itself by splitting and pairing up with their complimentary pair and making new strand of DNA
• Red blood cells are the only cells that dont have a nuclei so they dont go through DNA replication
• Mitosis is a nuclear division in which one nuclei undergoes cell division to form 2 identical daughter cells.
• Mitosis is for the growth and repairing of cells
• Mitosis occurs in somatic cells or body cells
• Meiosis is a nuclear division in which one nuclei undergoes cell division to form 4 daigher cells who are all unique from eachother
• Miesos is for reproduction
• Meiosis occurs in sex cells or gamates
• Variations are the difference combination in individuals due to the environment and their genotype
• Crossing over is the process in which the homologous chromosomes exchange genetic information during cell division of prophase in meiosis
• Trait is the genetically determined characteristics of an organism
• Karyotype is the organism complete set of chromosomes. It is a map showing the organisms number of and structure of chromosomes
• Karyotype can help determine an individual potential disease or any possible sickness
• Homologous are chromosomes that codes for the same thing, they are found in the same location on chromosomes and are the same length. However, they are not identical