Most Important Diagrams For NEET UG 2026 (Day 14): Diagrams serve as indispensable tools in mastering the NEET UG syllabus, enabling precise visualization and recall of complex concepts in Biology. This is Day 14 of our series, “Most Important Diagrams for NEET UG 2026,” where we highlight essential diagrams that frequently appear in exams. Students are encouraged to practice these diagrams and related questions diligently to enhance accuracy and speed during the test.
MITOSIS
What is Mitosis?
Mitosis is an equational division where one parent cell divides to form two genetically identical daughter cells, maintaining the same chromosome number.
- Occurs in somatic cells
- Responsible for growth, repair, and regeneration
Stage-Wise Explanation
1. Early Prophase
- Chromatin fibres start condensing into visible chromosomes.
- Each chromosome has two sister chromatids joined by a centromere.
- Nuclear membrane and nucleolus are still present (beginning to disappear).
- Centrioles start moving towards opposite poles (in animal cells).
2. Late Prophase (Prometaphase)
- Nuclear membrane completely disintegrates.
- Spindle fibres begin to form.
- Chromosomes become shorter and thicker.
- Kinetochores develop at centromere.
3. Transition to Metaphase
- Spindle fibres attach to kinetochores of chromosomes.
- Chromosomes begin moving toward the equatorial plane.
4. Metaphase
- Chromosomes align at the equatorial plane (Metaphase plate).
- Each chromosome’s sister chromatids are attached to spindle fibres from opposite poles.
Easy Mnemonic to Remember Order
P – M – A – T “Please Make A Tea”
(Prophase → Metaphase → Anaphase → Telophase)
Key Points to Remember for NEET
- Chromosome condensation starts in Prophase.
- Nuclear membrane disappears in Late Prophase.
- Spindle fibres attach during Prometaphase.
- Chromosomes align at equator in Metaphase.
- Metaphase is ideal for karyotyping.
- Sister chromatids are joined by centromere until Anaphase.
PRACTICE QUESTIONS
Q.1. Assertion (A): In metaphase of mitosis, all chromosomes align at the cell’s equatorial plane forming the metaphase plate.
Reason (R): Spindle fibres attach to kinetochores located on the centromeres of each chromosome during metaphase.
A. A is true but R is false
B. Both A and R are true, and R is the correct explanation of A
C. Both A and R are true, but R is not the correct explanation of A
D. A is false but R is true
Q.2. Assertion (A): Anaphase of mitosis begins when the centromeres of each chromosome split and sister chromatids start moving toward opposite poles.
Reason (R): The separation of sister chromatids in anaphase is driven by shortening of kinetochore microtubules and elongation of polar microtubules.
A. Both A and R are true, but R is not the correct explanation of A
B. Both A and R are true, and R is the correct explanation of A
C. A is true but R is false
D. A is false but R is true
Q.3. Assertion (A): During prophase of mitosis, the nucleolus gradually disappears and chromatin condenses into distinct chromosomes.
Reason (R): Condensation of chromatin into chromosomes during prophase facilitates the equal distribution of genetic material during cell division.
A. Both A and R are true, but R is not the correct explanation of A
B. A is true but R is false
C. A is false but R is true
D. Both A and R are true, and R is the correct explanation of A
Q.4. Assertion (A): In telophase of mitosis, nuclear envelopes reappear around each set of chromosomes at the poles.
Reason (R): Reformation of nuclear envelopes in telophase helps restore normal nuclear functions such as transcription and RNA processing in daughter cells.
A. A is true but R is false
B. Both A and R are true, and R is the correct explanation of A
C. A is false but R is true
D. Both A and R are true, but R is not the correct explanation of A
Q.5. Assertion (A): Spindle fibre formation and disintegration of the nuclear envelope are characteristic features of prometaphase.
Reason (R): Disintegration of the nuclear envelope during prometaphase allows spindle microtubules to access and attach to chromosomes.
A. A is true but R is false
B. Both A and R are true, but R is not the correct explanation of A
C. A is false but R is true
D. Both A and R are true, and R is the correct explanation of A
Regular practice will solidify your understanding and boost performance. Proceed to Day 15 tomorrow for additional key visuals, and continue your consistent preparation toward achieving your medical aspirations.
Answers & Explanations
Ans.1. C. Both A and R are true, but R is not the correct explanation of A. The assertion correctly states that in metaphase, duplicated chromosomes line up on the metaphase plate, an imaginary plane equidistant from the two spindle poles. This alignment ensures each daughter cell will receive one chromatid from each chromosome. The reason correctly states that spindle fibres attach to kinetochores on the centromeres, but this attachment actually begins in prometaphase and continues.
Ans.2. B. Both A and R are true, and R is the correct explanation of A. In anaphase, the key event is splitting of centromeres followed by movement of sister chromatids toward opposite poles. This movement is powered largely by microtubule dynamics: kinetochore microtubules depolymerize (shorten) at the kinetochore or pole, pulling chromatids in, while polar microtubules extend and slide past each other to push poles apart.
Ans.3. D. Both A and R are true, and R is the correct explanation of A. During prophase, chromatin fibres supercoil into visible chromosomes, each made of two sister chromatids joined at a centromere. This condensed structure is crucial because the mitotic spindle must attach and move entire chromosomes efficiently.
Ans.4. B. Both A and R are true, and R is the correct explanation of A. During telophase, nuclear envelopes reappear, separating the genetic material into two distinct nuclei. This re-establishment of nuclear boundaries allows the resumption of transcription and RNA processing in each daughter nucleus, which had been largely paused during mitosis. Hence, R correctly explains the importance of A in functional terms.
Ans.5. D. Both A and R are true, and R is the correct explanation of A. The nuclear envelope’s disassembly allows the spindle apparatus to physically access condensed chromosomes. This direct contact is essential for proper kinetochore attachment and subsequent mitotic events, making R a valid explanation for A.
Share Your Scores In Comments Below!!
All The Best..
Read Also: Important Practice Questions For NEET UG 2026 (Day 32)
