Quiz & Worksheets - Cell Division and Growth

Cell division and growth are fundamental biological processes that allow organisms to develop, repair tissues, reproduce, and maintain life. Every living organism, from single-celled bacteria to multicellular humans, relies on precise control of cell division to function correctly.

This lesson is specially designed for students in Grades 9–11 studying GCSE, IGCSE, AP, and CBSE curricula. It includes interactive activity sheets, flashcards, revision tasks, and engaging learning activities to help you understand mitosis, meiosis, and the importance of cell division in living organisms.

🔬 Importance of Cell Division

Cells divide for several key reasons:

Growth: Multicellular organisms start as a single fertilized cell and grow by producing more cells.
Repair and Replacement: Damaged or worn-out cells, like skin or blood cells, are replaced through division.
Reproduction: In unicellular organisms, division allows reproduction, while in multicellular organisms, it contributes to gamete production.

Example: Human skin cells divide constantly to replace dead cells, maintaining the integrity of the skin barrier.

Mitosis Phases Learning Video

Animated explanation of the phases of mitosis showing chromosome movement and cell division.

Microscopic Real Video of Mitosis

Real microscopic footage showing actual cells undergoing mitosis in real-time.

Mitosis Explained with Diagrams

Detailed explanation of mitosis phases with clear diagrams and annotations.

Mitosis

Mitosis produces two genetically identical daughter cells with the same number of chromosomes as the parent cell. It occurs in somatic (body) cells.

Example: Skin cell repair, liver regeneration.

Phases of Mitosis:

Prophase: Chromosomes condense, spindle fibers form, nuclear envelope breaks down.
Metaphase: Chromosomes align at the cell's equator.
Anaphase: Sister chromatids separate and move to opposite poles.
Telophase: Nuclear membranes form around each set of chromosomes.
Cytokinesis: Cytoplasm divides, forming two daughter cells.

Meiosis

Meiosis produces four genetically unique daughter cells, each with half the number of chromosomes (haploid). It occurs in gamete-producing cells. (Produces sperm and eggs in humans)

Importance: Genetic diversity, sexual reproduction.

Key Features:

Two rounds of division: Meiosis I and II
Crossing over occurs → genetic variation

Meiosis I

Prophase I: Chromosomes condense and become visible. Homologous chromosomes pair up (synapsis). Crossing over occurs, exchanging genetic material. Spindle fibers begin to form.
Metaphase I: Homologous chromosome pairs line up along the equator of the cell. Spindle fibers attach to each chromosome.
Anaphase I: Homologous chromosomes separate and move to opposite poles. Sister chromatids remain attached.
Telophase I: Chromosomes arrive at the poles. The cell divides into two haploid cells (cytokinesis).

Meiosis II

Prophase II: Chromosomes condense again in each new cell. Spindle fibers form.
Metaphase II: Chromosomes line up single file along the equator.
Anaphase II: Sister chromatids separate and move to opposite poles.
Telophase II: Chromatids reach the poles. Nuclei reform, and four genetically unique haploid cells are produced after cytokinesis.

What is mitosis?

Mitosis is a type of cell division that produces two genetically identical daughter cells with the same number of chromosomes as the parent cell. It's used for growth and repair.

What happens during Prophase?

During prophase, chromosomes condense and become visible, the nuclear envelope breaks down, and spindle fibers begin to form.

What is the purpose of meiosis?

Meiosis produces four genetically unique daughter cells with half the chromosome number (haploid). It's essential for sexual reproduction and genetic variation.

What is crossing over?

Crossing over occurs during Prophase I of meiosis when homologous chromosomes exchange genetic material, creating genetic variation in offspring.

What happens during Metaphase?

During metaphase, chromosomes align at the cell's equator (metaphase plate), and spindle fibers attach to the centromeres.

What is cytokinesis?

Cytokinesis is the division of the cytoplasm that occurs at the end of mitosis or meiosis, resulting in two separate daughter cells.

What are sister chromatids?

Sister chromatids are two identical copies of a chromosome joined together at the centromere, formed after DNA replication.

What happens during Anaphase?

During anaphase, sister chromatids (or homologous chromosomes in meiosis I) separate and move to opposite poles of the cell.

Difference between diploid and haploid?

Diploid cells (2n) have two complete sets of chromosomes, while haploid cells (n) have one set. Meiosis produces haploid cells; mitosis maintains diploid.

What is Telophase?

During telophase, chromosomes reach the poles, nuclear membranes reform around each set of chromosomes, and chromosomes begin to decondense.

How many cells result from mitosis vs meiosis?

Mitosis produces 2 identical daughter cells. Meiosis produces 4 genetically unique daughter cells with half the chromosome number.

What are homologous chromosomes?

Homologous chromosomes are pairs of chromosomes (one from each parent) that have the same genes at the same locations but may have different alleles.