Sperm is the male sex cell. Egg is the female sex cell. How many chromosomes are in each of the above? 23 Somatic cells have 46 chromosomes. Another term for a sex cell is a germ cell. A zygote is an egg that has been fertilized by one sperm that contains half of the DNA (23 chromosomes) from mother and half from father (23 chromosomes). Mitosis is the second stage of the cell cycle. (PMAT) Somatic cells undergo mitosis. Meiosis is the process by which the number of chromosomes is reduced by half to form sex cells (sperm and egg). So one cell will undergo meiosis and produce four cells. If a cell has forty chromosomes then after meiosis how many will each cell have? 20 body (somatic) cells germ (sex) cells two cells foursame number of chromosomes half of the original number identical cells unique cells Mitosis occurs in body (somatic) cells while meiosis occurs in germ (sex) cells. Mitosis produces two cells while meiosis produces four. Mitosis produces the same number of chromosomes in the resulting cell while meiosis produces half of the original number. Mitosis produces identical cells while meiosis produces unique cells. This gives way to genetic variation. all living thingsone cell equal amounts of chromosomes from both parents. new ones are made They both occur in all living things. Both begin with one cell. In order for both mitosis and meiosis to occur, the cell must have equal amounts of chromosomes from both parents. It is essential for all living things to undergo both mitosis and meiosis because as cells die, new ones are made. Interphase- cell makes a copy of its DNA and centrioles are copied PMAT- The stages of mitosis when the cells nucleus divides into new nuclei. Cytokinesis- The cell membrane pinches in around the middle of the cell and it splits into two. A- Interphase B- Prophase C- Metaphase D- Anaphase E- Telophase F- Cytokinesis nitrogen basessugars (deoxyribose phosphates nitrogen bases, sugars (deoxyribose) and phosphates. The sugar and phosphates make up the sides of the ladder while the nitrogen bases make up the rungs. They are molecules that contain the element nitrogen and they are adenine, cytosine, guanine and thymine. They are the rungs of the DNA ladder. T-C-C-A-G-T-T-G-A Heredity- passing of physical characteristics from parents to offspring Genetics- the scientific study of heredity Traits- a different form of a characteristic Allele- different forms of a gene Dominant- one whose trait ALWAYS show up in the organism when the allele is present. Recessive- one whose trait is HIDDEN whenever the dominant allele is present. Homozygous- two identical alleles for a trait (DD or dd) Heterozygous- two different alleles for a trait (Dd) A purebred is a homozygous individual. A hybrid is a heterozygous individual. Genotype- genetic makeup or allele combination (AA) Phenotype- organisms physical makeup or visible traits. (blonde hair) Gene- A section of DNA that controls a trait. Chromosome- made up of many genes joined together. You have twenty three pairs of chromosomes yet each cell contains tens of thousands of genes. Mendelian traits refer to traits such as dimples, freckles, etc. and NOT sex-linked Think Paper Pets Ww W W w w Genotype- 100% Ww Phenotype- 100% widows peak A dominant allele always shows up in the organism when the allele is present. A recessive allele is hidden when the dominant allele is present. Since males only have one X chromosome, they will not be able to mask the normal allele like females can with their second X. In females, a dominant allele on one X will mask a recessive on the other X. Males only have one X, so that is not a possible scenario. False The X chromosome carries many genes such as certain sex related disorders. Hemophilia Colorblindness If a man who has colorblindness marries a woman who is normal, what is the outcome that their sons will be colorblind? Their daughters? X E X e X E Y X E XeXe Y None of their sons will be colorblind. Their daughters will both be carriers but will not be colorblind. X E X E X e X E YX e Y X E X e XEXE Y There is a 25% chance that their child will have the disorder and a 50% chance among the males. Normal woman marries colorblind man, two female carriers, two normal males Sons marry carriers and have normal son, normal daughter and carrier daughter and colorblind son Hybridization Inbreeding Genetic Engineering Inbreeding involves the breeding of organisms so as to keep the BEST traits Hybridization involves the breeding of organisms to create something NEW Its purpose would be to create new organisms to enhance our lifestyle. Production of insulin for diabetes Genetically engineered plants Genetically modified salmon (fast growing) Medicinal Eggs innovations/photos/12-bizarre-examples-of- genetic-engineering/glow-in-the-darkinnovations/photos/12-bizarre-examples-of- genetic-engineering/glow-in-the-dark