290 likes | 312 Views
Chapter 4 Notes. Cell Reproduction. Mitosis clip. Mitosis – when the nucleus of a cell divides to form 2 identical cells. Chromosome – Structure in the nucleus that contains DNA. Centromere – holds chromosomes together. 5 Phases in Mitosis.
E N D
Chapter 4 Notes Cell Reproduction
Mitosis clip Mitosis – when the nucleus of a cell divides to form 2 identical cells.
Chromosome– Structure in the nucleus that contains DNA.Centromere – holds chromosomes together.
5 Phases in Mitosis 1. Interphase – nucleus can be seen, chromosomes duplicating themselves.
2. Prophase – chromosome pairs are visible, centrioles move to opposite ends.
3. Metaphase – chromosome pairs line up across center and attach to spindle fibers.
4. Anaphase – strands of chromosomes pulled apart and move to opposite ends of each other.
5. Telophase – The cytoplasm of both cells begins to separate. • Mitosis clip
Diploid – cell that has 46 chromosomes (body cells) Haploid – cell that has 23 chromosomes (sex cells) Zygote – when egg and sperm combine (start of life) Zygote Development Stages of embryo Zygote
Meiosis clip Meiosis – When the nucleus divides to make sex cells.
4 Phases in Meiosis I • Prophase I • Metaphase I • Anaphase I • Telophase I
4 Phases in Meiosis II • Prophase II • Metaphase II • Anaphase II • Telophase II
Asexual Reproduction – new organisms are produced by one parent. Video asexual reproduction
3 Kinds of Asexual Reproduction 1. Fission – division of organism into 2 equal parts.
2. Budding – new organism grows from the parent. Hydra Budding
Video :23 3. Regeneration- making new body parts. Starfish
Video stop at 2:37 • Rosalind Franklin was the first person to discover DNA. • The 1st DNA model was made by Watson and Crick. DNA is made up of 4 nitrogen bases • Adenine • Guanine • Cytosine • Thymine
Genes A section of DNA on chromosomes.
How DNA Copies Itself Step 1: enzyme breaks the nitrogen bases. 2 strands separate Step 2: bases pair up with new bases Step 3: sugar and phosphate form the sides of DNA.
Unusual Bad Mutations Bad Mutation
Brain Pop: DNA Mutation – any permanent change in the DNA sequence of a gene or chromosome of a cell.