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# Cell Structure and Cell Theory ## Cell Components **Plant Cell:** * **Cell Wall:** Barrier outside the cell membrane, found in plant and bacterial cells. Large in plant cells, small in animal cells. * **Vacuoles:** Storage for water, food, and enzymes. * **Chloroplast:** Found only in plan...

# Cell Structure and Cell Theory ## Cell Components **Plant Cell:** * **Cell Wall:** Barrier outside the cell membrane, found in plant and bacterial cells. Large in plant cells, small in animal cells. * **Vacuoles:** Storage for water, food, and enzymes. * **Chloroplast:** Found only in plant cells. * **Centriole:** Aids in cell division, made of microtubules. * **Flagella:** Present only in gametes (reproductive cells) of plants. **Animal Cell:** * **No Cell Wall:** Does not have a cell wall. * **Small/No Vacuole:** Vacuoles present, but smaller than in plant cells. * **No Chloroplast:** Chloroplasts are not present in animal cells. * **Flagella:** Present in some animal cells (not always). ## Cell Theory **3 Contributors to Cell Theory:** 1. **Robert Hooke:** Used a crude microscope to observe cork, coined the term "cells." 2. **Anton van Leeuwenhoek:** Improved the microscope, observed living cells. 3. **Matthias Schleiden:** Proposed plants are made of cells. 4. **Theodor Schwann:** First statement of cell theory: "All plants are made of cells." 5. **Rudolf Virchow:** Second statement of cell theory: "All cells come from pre-existing cells." ## Sexual/Asexual Reproduction **Life Cycle:** * Fertilization * Zygote * Embryogenesis * Embryo * Organogenesis * Young * Maturation * Adult * Gametogenesis * Gametes **Metamorphosis:** * A feature in some organisms that leads to rapid change from immature to adult stages. * Ex: Beetles, mosquitoes, butterflies (complete metamorphosis), Dragonflies, Grasshoppers (incomplete metamorphosis). **Type:** * Complete metamorphosis: Distinct larval and pupal stages (ex. Butterflies). * Incomplete metamorphosis: Aquatic juvenile stage, no pupa stage (ex. Dragonflies, grasshoppers).