Science Notes PDF

# SCIENCE NOTES ## Parts of a cell - **Cell Membrane:** Separates cell from the outer environment. - **Golgi Complex:** Packages proteins into membrane-bound vesicles before it gets transported. - **Membrane Receptor:** Binds to ligands and generates intracellular signaling to impose acute or tran...

# SCIENCE NOTES ## Parts of a cell - **Cell Membrane:** Separates cell from the outer environment. - **Golgi Complex:** Packages proteins into membrane-bound vesicles before it gets transported. - **Membrane Receptor:** Binds to ligands and generates intracellular signaling to impose acute or transcriptional changes. - **Mitochondria:** Uses aerobic respiration to generate adenosine triphosphate for chemical energy. - **Nucleolus:** Produces and assembles ribosomes. - **Endoplasmic Reticulum:** The transport system for the cell which also folds protein. - **Chromatin:** Chromatin is a complex of DNA and proteins within the nucleus of eukaryotic cells. Nuclear DNA does not appear in free linear strands, it is highly condensed, and wrapped around nuclear proteins in order to fit inside the nucleus. - **Two Forms:** - **Euchromatin:** Is less condensed and can be transcribed. - **Heterochromatin:** More condensed and typically can't be transcribed. - **Chromosome:** Chromosomes are thread-like structures made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell. In plants and animals, chromosomes reside in the nucleus of cells. Humans have 23 chromosomes for a total of 46. - **Interphase:** - **G1:** Rest - **S:** DNA Replication - **G2:** Preparation - **Mitosis:** Genetically identical - **Meiosis:** Genetically unique, contains half as much DNA. - **Prophase:** - The first stage. - DNA has been replicated. - The condensation of the chromatin reticulum and disappearance of the nucleolus. - **Metaphase:** - Aligns the center. - Dissolves the nucleus. - Chromosomes are aligned in a single file. - **Anaphase:** - Splits chromosomes. - Moves them to opposite sides. - **Telophase:** When almost finished, it re-establishes its normal structure in cytokinesis. - **Cytokinesis:** - Last phase. - Makes two daughter cells. ## Parts of a microscope 1. Eyepiece tube or body tube 2. Nosepiece 3. Objective lenses 4. Stage clips 5. Stage 6. Diaphragm 7. Illuminator 8. Eyepiece/Ocular lens 9. Arm 10. Course focus 11. Fine focus 12. Base ## Asexual vs. Sexual Reproduction - **Asexual:** - Uniparental. - Faster. - Gametes aren't formed. - No fertilization. - More offspring. - **Sexual:** - Bi-parental. - Takes longer. - Gametes are formed. - Fertile. - Less offspring.