Mitosis
Karyokinesis stages and cytokinesis, and equational division of chromosomes. (Biology › Cell Cycle and Cell Division, NEET UG syllabus.)
What is Mitosis?
The division of the nucleus during cell division.
Key formula / rule: Chromosome Number during Mitosis
Key points
- Describe the different phases of mitosis (Prophase, Metaphase, Anaphase, Telophase).
- Explain the key events occurring in each phase of karyokinesis.
- Differentiate between cytokinesis in plant and animal cells.
- State the significance of mitosis for living organisms.
Common exam trap
Confusing mitosis with meiosis (equational vs. reductional division).
Definitions
- Term
Karyokinesis
- Meaning
The division of the nucleus during cell division.
- Term
Cytokinesis
- Meaning
The division of the cytoplasm following nuclear division.
- Term
Metaphase Plate
- Meaning
The imaginary plane equidistant from the two poles of a cell where chromosomes align during metaphase.
- Term
Sister Chromatids
- Meaning
Two identical copies of a chromosome joined together by a centromere, formed during DNA replication.
- Term
Spindle Fibres
- Meaning
Microtubule structures that form during cell division and are involved in separating chromosomes.
Learning objectives
Describe the different phases of mitosis (Prophase, Metaphase, Anaphase, Telophase).
Explain the key events occurring in each phase of karyokinesis.
Differentiate between cytokinesis in plant and animal cells.
State the significance of mitosis for living organisms.
Identify the stage of mitosis from diagrams or micrographs.
Formulae
- Name
Chromosome Number during Mitosis
- Note
If a diploid parent cell (2n) undergoes mitosis, it produces two diploid daughter cells (2n). The number of chromosomes remains constant.
- Expression
2n → 2n
- Name
DNA Content during Mitosis
- Note
If the DNA content of a diploid cell is 2C, after S-phase it becomes 4C. After mitosis, each daughter cell will have 2C DNA content.
- Expression
2C → 4C (after S-phase) → 2C (per daughter cell)
Prerequisites
Basic understanding of cell structure (nucleus, chromosomes, cytoplasm, cell wall/membrane).
Knowledge of the cell cycle (Interphase: G1, S, G2 phases).
Concept of DNA and chromosomes (chromatids, centromere).
Common mistakes
Confusing mitosis with meiosis (equational vs. reductional division).
Incorrectly identifying the stage based on chromosome arrangement.
Forgetting the role of the centromere in chromosome movement.
Not understanding the difference in cytokinesis between plant and animal cells.
Assuming DNA replication occurs during mitosis itself (it occurs in S-phase of interphase).
Keywords
Mitosis
Karyokinesis
Cytokinesis
Prophase
Metaphase
Anaphase
Telophase
Equational Division
Somatic Cells
Cell Cycle
Chromosomes
Spindle Fibres
Metaphase Plate
Centromere
Cleavage Furrow
Cell Plate
Practice preview
A cell has 2n=4 chromosomes. After mitotic anaphase, how many chromatids and chromosomes will be present in the cell, respectively, before cytokinesis is complete?…
hard
During metaphase, the chromosomes are attached to the spindle fibres by their:…
hard
How does cytokinesis in an animal cell differ from that in a plant cell?…
medium