Key Concepts Covered in Meiosis Multiple Choice Questions
Meiosis is a mechanism in which a single cell divides twice to produce four cells that contain half of the original amount of genetic data. Those cells are our sex cells-male sperm, female eggs.
One cell divides up twice during meiosis to create four daughter cells. These four daughter cells are only half as numerous as chromosomes of the parent cell-haploid.
Meiosis is divisible into nine stages. These are divided between the first division of the cell (meiosis I) and the second division thereof (meiosis II).
Solved MCQs on Meiosis
1. The RNA and protein synthesis occurs in______
M phase
S phase
G1 Phase
G2 phase
Answer: c
Explanation: The first phase of the cell cycle is phase G1. It is an integral part of the Interphase. RNA and protein synthesis occurs in Phase G1.
2. When does synapsis occur at Meiosis?
Zygotene
Leptotene
Diplotene
Pachytene
Answer: a
Explanation: Zygotene is the second stage of the Meiosis prophase. Bivalents are seen as shaping the synaptonemal complexes. Synapsis facilitates the exchange of genetic material between the chromosomes.
3. Spindle fibers are formed by___________
Spindles
Tubulin
Flagella
Humulin
Answer: b
Explanation: Spindle fibers are made up of microtubules. Microtubules are polymers of alpha- and beta-tubulin dimers. Tubulin is a Globular Protein It helps in dividing cells.
4. Chromosomes break during?
Prophase
Anaphase
Metaphase
Telophase
Answer: b
Explanation: The 3rd stage of cell division is anaphase. During this point, chromosomes move away from each other towards opposite spindle poles.
5. Replication of centriole occurs in ______________
Interphase
Prophase
Metaphase
Anaphase
Answer: a
Explanation: Interphase is the longest phase of the cell cycle in which typical cells submit most of their lives. It is divided into the G1, S phase, and G2 phase. The S phase is characterized by biosynthetic activity such as duplication of DNA and centrioles.
6. Colchicine arrests which of the following stages of cell division?
Anaphase
Telophase
Interphase
Metaphase
Answer: d
Explanation: Colchicine is an alkaloid in its natural state. It is used to treat acute gout attacks. Colchicine arrests metaphase for the stage of the division of cells.
7. Cell Plate is laid during __________
Cytokinesis
Karyokinesis
Interphase
Metaphase
Answer: a
Explanation: Cytokinesis is a process of cell division that divides the cytoplasm of a parental cell into two daughter cells.
8. Polyploidy may be induced artificially by__________
Self-pollination
Linebreeding
Inbreeding
Colchicine
Answer: d
Explanation: Polyploidy’s condition where diploid cells normally get one or more extra sets of chromosomes. Colchicine can cause polyploidy, artificially.
9. There are chromosomes arranged along the equator ___________
Prophase
Metaphase
Anaphase
Telophase
Answer: b
Explanation: Metaphase is the 2nd level of cell division. During metaphase, the chromosome organizes itself in the middle of the cell.
10. Chiasmata formation takes place during __________
Prophase I
Metaphase I
Anaphase I
Telophase I
Answer: a
Explanation: The formation of chiasmata takes place during prophase I, and chromosomes are duplicated during this period. Chiasmata is a spot where paired chromosomes stay in contact during the first meiosis metaphase.
Test Your Knowledge
1. The word meiosis had been coined by?
Robertson
Blackmann
Flemming
Farmer and Moore
2. During meiosis, chromatids of individual chromosomes separate during ___?
Metaphase I
Anaphase I
Anaphase II
Metaphase II
3. Meiosis is of evolutionary significance as it produces ___?
Gametes
generally similar daughter cells
recommendations
four daughter cells
4. In metaphase I, the centromeres undergo division.
do not divide
divide but do not separate
are not similar
undergo division
5. Call the step of prophase I when synaptonemal complex dissolves when chromatids are transparent and tetrads are considered bivalents?
Pachytene
Diakinesis
Diplotene
Zygotene
The above article provides solved MCQs on Meiosis. The explanations of the MCQs are also given. Students can refer to this article for practicing questions. It will help them to revise the concept of Meiosis.
FAQs on Meiosis MCQs: Practice Questions & Answers
1. What are the high-weightage topics within Meiosis for NEET MCQs?
For NEET and other competitive exams, the most frequently tested topics in Meiosis include:
- The five sub-stages of Prophase I (Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis) and the key events in each.
- The process of crossing over in the Pachytene stage and the formation of chiasmata.
- The fundamental difference between Meiosis I (reductional division) and Meiosis II (equational division).
- Changes in chromosome number (n) and DNA content (C) through each stage.
- The events of Anaphase I (separation of homologous chromosomes) versus Anaphase II (separation of sister chromatids).
2. If a parent cell has 2n=20 chromosomes, what is the chromosome and chromatid count per cell after Meiosis I and Meiosis II?
This is a common numerical problem in MCQs.
- After Meiosis I: The cell becomes haploid. It will have n=10 chromosomes. Since each chromosome still consists of two sister chromatids, the chromatid count will be 10 x 2 = 20 chromatids.
- After Meiosis II: The sister chromatids separate. Each of the four daughter cells will have n=10 chromosomes, and each chromosome will have only one chromatid, resulting in 10 chromatids per cell.
3. What is the key difference between Anaphase I and Anaphase II, a common point of confusion in MCQs?
The primary distinction, which is a frequent trap in MCQs, lies in what separates:
- In Anaphase I, homologous chromosomes separate and move to opposite poles. The centromere does not split, and sister chromatids remain attached.
- In Anaphase II, the centromere splits, and the sister chromatids separate, moving to opposite poles. This event is similar to Anaphase in mitosis.
4. How is DNA replication in meiosis different from mitosis, and why is this crucial for sexual reproduction?
The critical difference is that in meiosis, DNA replication occurs only once during the S-phase of Interphase, but the cell divides twice (Meiosis I and Meiosis II). In mitosis, DNA replication is followed by a single cell division. This 'one replication, two divisions' mechanism is crucial because it ensures the resulting gametes are haploid (n). This halving of chromosome number is essential to restore the normal diploid (2n) state of the species during fertilisation.
5. What are the genetic consequences if a germ cell fails to undergo meiosis correctly, for instance, through non-disjunction?
Failure of chromosomes to separate correctly during meiosis, known as non-disjunction, has severe genetic consequences. It leads to the formation of gametes with an abnormal number of chromosomes (a condition called aneuploidy). If such a gamete participates in fertilisation, the resulting zygote will have a chromosomal disorder, such as Trisomy (e.g., Down syndrome, Trisomy 21) or Monosomy, which are often associated with serious developmental issues or are non-viable.
6. Why is Prophase I of meiosis considered more complex and significant than Prophase of mitosis?
Prophase I is far more complex because it is the stage where the most significant events for genetic diversity occur. It is subdivided into five distinct stages where key processes happen that are absent in mitotic prophase. The most important of these is synapsis (pairing of homologous chromosomes) and crossing over (exchange of genetic material between non-sister chromatids). These events create new gene combinations, which is the primary source of variation in sexually reproducing organisms.
7. How does meiosis contribute to both the continuity of a species and its evolution?
Meiosis serves two dual purposes:
- Continuity: By producing haploid (n) gametes, meiosis ensures that when fertilisation occurs, the diploid (2n) chromosome number of the species is restored and maintained across generations. This preserves the genetic identity of the species.
- Evolution: Through crossing over and the independent assortment of homologous chromosomes, meiosis generates immense genetic variation in the offspring. This variation is the raw material upon which natural selection acts, allowing populations to adapt and evolve over time.
