6-Interphase-and-Mitostic-Phases-STUDENT-COPY
CELL CYCLE AND CELL DIVISION
Introduces the concept of the cell cycle, including interphase, mitosis, and meiosis.
Importance of Cell Division in Embryonic Development
Cell division is crucial for embryonic development as it allows the organism to grow and develop from a single cell into a larger, multicellular organism.
Facilitates differentiation and the formation of various tissues and organs.
Definition of Cell Division
Cell division is the process by which a parent cell divides into two or more daughter cells.
Page 4: Overview of the Cell Cycle
The cell cycle consists of phases that prepare the cell for division and the actual division process.
Page 5: Types of Cell Division
Mitosis: Produces two identical cells, each with the same number of chromosomes as the parent cell.
Meiosis: Produces four daughter cells, each with half the number of chromosomes of the parent cell.
Page 6: Key Terminology Related to DNA and Chromosomes
DNA: Deoxyribonucleic acid, the genetic material in eukaryotic cells.
Histones: Proteins that condense DNA into chromatin.
Chromatin: Complex of DNA and histones found in eukaryotic cells during interphase.
Chromatid: One of the two identical halves of a replicated chromosome.
Chromosome: Consists of two sister chromatids connected at the centromere.
Homologous Chromosome: A pair of chromosomes containing the same gene sequence.
Tetrad: Four chromatids of a homologous pair.
Page 7: Parts of Chromosomes
Centromere: Joins sister chromatids and attaches spindle fibers during division.
Centrioles: Organelles that organize the spindle fibers during cell division.
Kinetochore: Protein complex at the centromere where spindle fibers attach.
Page 8: Chromosome Structure
Illustrates key features such as sister chromatids, arms, centromere, and telomeres.
Page 9: Diploid vs. Haploid
Diploid: Cells with pairs of chromosomes, expressed as 2(n).
Haploid: Cells with a single set of chromosomes, expressed as (n).
Page 10: Overview of Cell Cycle
Cells undergo cycles of growth, development, and division to facilitate organism growth and repair.
Page 11: Interphase
This phase is the longest period of the cell cycle during which cells grow and carry out metabolic functions while preparing for division.
Page 12: Gap 1 (G1) Phase
First growth phase where the cell increases in size and replicates materials, excluding genetic material.
Length of G1 varies based on nutrient availability. Insufficient nutrients cause entry into G0 phase.
Page 13: Gap 0 (G0) Phase
Known as the resting phase; cells are quiescent and cannot enter the S phase to replicate DNA.
Some cells remain in this phase due to genetic programming (e.g., neurons, heart muscle).
Page 14: Synthesis Phase (S Phase)
The DNA replication occurs during S phase, providing equal genetic material to daughter cells.
Page 15: Gap 2 (G2) Phase
The second growth phase where the cell continues to grow and synthesizes proteins essential for cell division.
Page 16: Chromatin Types
Heterochromatin: Tightly packed, less accessible.
Euchromatin: Loosely packed, making DNA more accessible for transcription.
Page 17: Start of Cell Division
Chromosomes begin to condense and become visible at the end of interphase.
Page 18: Replication in S Phase
Depicts chromosome replication into sister chromatids ready for mitosis.
Page 19: Overview of Mitosis Phases
Mitosis includes Prophase, Metaphase, Anaphase, and Telophase.
Page 21: Prophase
Chromosomes condense after DNA replication; nuclear envelope disappears, and spindle fibers form.
Centrosomes duplicate and begin to move apart.
Page 22: Supercoiling of Chromosomes
Chromosomes must supercoil for compact storage in the nucleus, especially during mitosis.
Page 23: Prophase Details
DNA condenses further into visible chromosomes with two sister chromatids.
Page 24: Centrosomes in Prophase
Centrosomes organize microtubules essential for mitotic spindle formation.
Page 25: Spindle Formation in Prophase
Microtubules grow between centrosomes, forming the mitotic spindle.
Page 26: Centrioles
Centrioles help organize and anchor microtubules during cell division.
Page 27: Prometaphase
Nuclear envelope breakdown occurs, allowing spindle fibers to attach to chromosomes.
Page 28: Kinetochore Formation
Kinetochore forms at each centromere, binding spindle microtubules and facilitating chromosome movement.
Page 29: Metaphase
Chromosomes align at the metaphase plate, equidistant from the poles.
Page 30: Alignment of Chromosomes
Spindle fibers tug on sister chromatids to ensure proper alignment.
Page 31: Anaphase
Shortest phase where sister chromatids are pulled apart to opposite sides, elongating the cell.
Page 32: Anaphase Details
Highlights the mechanism of chromatid separation by spindle fibers.
Page 33: Telophase
Final mitotic phase; chromosomes de-condense and new nuclear membranes form around each set.
Page 34: Telophase Details
Cleavage furrow forms, leading toward cytoplasmic division.
Page 35: Cytokinesis Overview
Last phase of cell division; cytoplasm divides, creating two identical daughter cells.
Page 36: Cytokinesis in Plant Cells
New cell wall formation via vesicles forming a cell plate that expands outward.
Page 37: Cell Plate Formation
Details the process of cell plate formation during cytokinesis in plant cells.
Page 38: Cytokinesis in Animal Cells
The membrane contracts, creating a cleavage furrow that deepens until the cell divides.
Page 39: Cytokinesis Details
Description of contraction and final separation in animal cells during cytokinesis.
Page 40: Results of Mitosis - Reproduction
Mitosis in unicellular organisms results in identical offspring.
Example of paramecium reproduction process.
Page 41: Results of Mitosis - Growth
Essential for increasing cell number during organism growth; significant during human development post-fertilization.
Page 42: Results of Mitosis - Repair
Cell division is critical for repairing damaged cells, as detailed in bone healing processes.
Page 43: Results of Mitosis - Replacement
Damaged cells need replacement; stem cells can differentiate into various cell types.
Page 44: Types of Cell Division
Comparison of mitosis and meiosis in terms of chromosome number and outcome.
Page 45: Comparison of Mitosis vs. Meiosis
Mitosis: Somatic cells, diploid, 1 cell division creates 2 diploid cells.
Meiosis: Gametes, haploid, 2 cell divisions create 4 haploid cells.
Page 46: Observation Section
Encourages observation of cell structures or processes.
Page 47: Cell Abnormalities
Discussion questions regarding diseases/disorders related to cell abnormalities and addressing them as a future practitioner.
Page 48: Genetic Notation
Illustration of genetic notation or codification.
Page 49: Additional Genetic Notation
More genetic notation examples or patterns.
Page 50: Cancer Cells vs. Normal Cells
Differences in growth factors and division behavior between cancer and normal cells.
Page 51: Causes of Cancer Cells
Hypothetical series of mutations leading to cancer:
Initial mutation inactivates negative regulators.
Subsequent mutations affect positive regulators and genome stability.
Page 52: Dyskeratosis Congenita
A rare genetic disorder affecting telomeres, leading to bone marrow failure and lung disease.