Cell cycle and cell division 45 MCQ 💥nee 2026🔥 ncert line by line MCQ practice score booster series скачать в хорошем качестве

Cell cycle and cell division 45 MCQ 💥nee 2026🔥 ncert line by line MCQ practice score booster series

Cell Cycle and Cell Division (For NEET Level) 🔬 Cell Cycle The cell cycle is the sequence of events by which a cell grows and divides to form two daughter cells. It is divided into two main phases: 1️⃣ Interphase (Longest Phase – ~95% of cycle) Interphase has three stages: G₁ phase (Gap 1) Cell grows in size, synthesizes RNA and proteins. S phase (Synthesis phase) DNA replication occurs. Each chromosome duplicates to form sister chromatids. G₂ phase (Gap 2) Further growth and preparation for mitosis (spindle protein synthesis). 👉 Cells that do not divide enter G₀ phase (inactive stage). 2️⃣ M Phase (Mitotic Phase) Includes: Karyokinesis (division of nucleus) Cytokinesis (division of cytoplasm) 🔬 Cell Division Cell division occurs by two main types: 1️⃣ Mitosis (Equational Division) Occurs in somatic cells. Maintains chromosome number. Stages of Mitosis: Prophase Chromosomes condense Nuclear membrane disappears Spindle fibers form Metaphase Chromosomes align at equatorial plate Best stage to study chromosome morphology Anaphase Sister chromatids separate Move towards opposite poles Telophase Nuclear membrane reappears Chromosomes decondense 👉 Followed by Cytokinesis In plants: Cell plate formation In animals: Cleavage furrow Significance of Mitosis: Growth Repair Asexual reproduction 2️⃣ Meiosis (Reduction Division) Occurs in germ cells. Reduces chromosome number to half. Meiosis I (Reductional Division) Prophase I has 5 stages: Leptotene Zygotene (Synapsis) Pachytene (Crossing over) Diplotene Diakinesis Then: Metaphase I Anaphase I (Homologous chromosomes separate) Telophase I Meiosis II (Equational Division) Similar to mitosis. Significance of Meiosis: Formation of gametes Genetic variation Maintains chromosome number across generations 📚 45 MCQs – Cell Cycle & Cell Division (NEET Level) 1. DNA replication occurs in: A) G₁ B) S phase ✅ C) G₂ D) M phase 2. Longest phase of cell cycle is: A) M phase B) G₂ C) Interphase ✅ D) Prophase 3. Equational division occurs in: A) Meiosis I B) Meiosis II C) Mitosis ✅ D) Both B & C ✅ 4. Crossing over occurs during: A) Leptotene B) Zygotene C) Pachytene ✅ D) Diplotene 5. Chromosomes align at equatorial plate during: A) Prophase B) Metaphase ✅ C) Anaphase D) Telophase 6. Synapsis occurs in: A) Leptotene B) Zygotene ✅ C) Pachytene D) Diplotene 7. Best stage to study chromosome morphology: A) Prophase B) Metaphase ✅ C) Anaphase D) Telophase 8. Separation of sister chromatids occurs in: A) Anaphase of mitosis ✅ B) Anaphase I C) Metaphase I D) Telophase I 9. Reduction in chromosome number occurs in: A) Mitosis B) Meiosis I ✅ C) Meiosis II D) Cytokinesis 10. Cell plate formation is seen in: A) Animal cells B) Plant cells ✅ C) Bacteria D) Fungi (Continuing in same NEET pattern) 11–45 (Answer Key Included Below) G₀ phase is — Resting phase ✅ Homologous chromosomes separate in — Anaphase I ✅ Spindle fibers attach at — Centromere ✅ Tetrad formation occurs in — Pachytene ✅ Karyokinesis means — Nuclear division ✅ Cytokinesis in animals by — Cleavage furrow ✅ Number of daughter cells in meiosis — 4 ✅ Genetic variation mainly due to — Crossing over ✅ Mitosis maintains — Chromosome number ✅ S phase occurs in — Interphase ✅ Chromatin condenses in — Prophase ✅ Recombination nodules appear in — Pachytene ✅ Chiasmata visible in — Diplotene ✅ DNA content doubles in — S phase ✅ Haploid cells formed by — Meiosis ✅ Two divisions occur in — Meiosis ✅ Equatorial plate forms in — Metaphase ✅ Spindle disappears in — Telophase ✅ Reduction division term used for — Meiosis I ✅ Centrioles present in — Animal cells ✅ Mitosis discovered by — Walther Flemming ✅ Meiosis term given by — Farmer and Moore ✅ Crossing over leads to — Variation ✅ Daughter cells identical in — Mitosis ✅ Homologous pairing occurs in — Zygotene ✅ Chromosome movement toward poles — Anaphase ✅ Nuclear membrane disappears in — Prophase ✅ Cytoplasm divides in — Cytokinesis ✅ Chromosome number halves in — Meiosis I ✅ Spindle made of — Microtubules ✅ Meiosis occurs in — Germ cells ✅ Cell cycle regulated by — Cyclins ✅ DNA synthesis stops in — M phase ✅ Checkpoint present in — G₁ phase ✅ Genetic stability maintained by — Mitosis ✅