Genetics

• DNA (deoxyribonucleic acid) contains genetic information that determines an organism's characteristics.
• Heredity: the passing on of physical or mental characteristics genetically from one generation to another
• Traits are inherited characteristics that are passed from parents to offspring and are expressed in the phenotype which is a genetic code.
• Genetic code is written in a molecule called deoxyribonucleic acid which is located in the nucleus of a cell.
• Natural Variation means no two living things are ever completly identical. The differences are called variations.
• Chromosomes - long strands of DNA that carry genes and are found in the nucleus of a cell
• Each cell contains about two meters of DNA. DNA condences, coils and shortens to form chromosomes.
• DNA molecule = many units of heredity (genes). A gene is the basic unit of heredity; these are passed from one generation to the next.
• Cell Division is the process by which a cell divides to produce two identical daughter cells. There are two types of cell division: Mitosis and Meiosis.
• Mitosis is a process where a single cell divides into two identical daughter cells.
• Cell Division helps to maintain the genetic information of the cell and to replace cells that have been damaged. It also helps the body to grow, repair and reproduce.
• The difference between mitosis and meiosis is that mitosis produces two identical daughter cells while meiosis produces four haploid daughter cells.
• A cell contains chromosomes which is inside DNA
• There are 46 chromosomes in a human cell, 23 pairs of chromosomes. 44 chromosomes (or 22 pairs) are non-sex called Autosomes. The 23rd pair is the sex chromosome pair. XX - Female, XY - Male
• Genetics is the study of heredity and natural variation in organisms.
• DNA has a double helix, which is a structure of two strands of DNA held together by hydrogen bonds. Its scientific name is deoxyribonucleic acid and its role is to store genetic information and order nitrogen bases about how to make protein. It controls cell activities such as division and heredity.
• DNA is a large molecule made up of smaller blocks called nucleotides.
• Nucleotides are the monomers of DNA and RNA. Monomers are the building blocks of nucleic acids.
• Each base is attached to a sugar molecule and phosphate group to form a nucleotide.
• In DNA, Adenine always binds with Thymine and Cytosine always binds with Guanine.
• The four types of nucleotide bases found in DNA are adenine, thymine, cytosine and guanine.
• Each nucleotide consists of a phosphate group, a pentose sugar (deoxyribose), and a nitrogenous base.
• Two types of sugar are used in nucleotides; deoxyribose sugar, which is used in DNA, and ribase, which is used in RNA.
• Mitosis's first stage is called interface, and before a cell divides it makes a copy of its DNA and replicates it.
• The second stage of mitosis is prophase which is where chromosomes become visible, the nuclear membrane disappears and spindle fibers appear.
• After prophase, metaphase happens and the chromosom.es line up along the equator of the cell
• After metaphase, anaphase occurs and the chromosomes split in half and are pulled to opposite sides of poles.
• After anaphase, the final phase occurs and this is called telophase. THis is where two new cells ready to be formed, the nucleus starts to reform and then two identical daughter cells are formed and separated.
• What does DNA contain and what does it determine?

  Contains genetic information, determines an organisms characteristics