Important Questions Class 11 Biology Chapter 10 Cell Cycle and Cell Division for CBSE

Important Questions for Class 11 Biology 10th Chapter Cell Cycle and Cell Division MCQ, Very Short, Short Type, Long Type

CBSE Class 11 Important Questions for Class 11 Biology Chapter 10 Cell Cycle and Cell Division all MCQ Type, Very Short Type, Assertion Reason Type, Case Study, Short Type and Long Type Questions with Answers by Expert. Important Questions for Section A, B, C, D Class 11 Biology Chapter 10.

  • MCQs

(1) The quiescent phase refers to the

(a) G0 phase 

(b) G1 phase

(c) G2 phase

(d) S phase

(2) Assertion: The amount of DNA per cell doubles in S- Phase

Reason: this is due to increase in the chromosome number

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(3) Assertion: In animal cells, during the S phase, DNA replication begins in the nucleus, and the centriole duplicates in the cytoplasm.

Reason: During the G2phase, proteins are synthesized in preparation for mitosis while cell growth continues.

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(4) Centromeres split and chromatids separate and Chromatids move to opposite poles in

(a) Prophase

(b) Metaphase

(c) Anaphase

(d) Telophase

(5) Nucleolus, Golgi complex and ER reform in

(a) Prophase

(b) Metaphase

(c) Anaphase

(d) Telophase

(6) Assertion: Mitosis is also called equational division

Reason: Mitosis is usually restricted to the diploid cellsonly

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(7) Assertion: The synthesis of DNA occurs only in a restricted portion of the interphase during S period.

Reason: M phase is preceded and followed by two “gap” periods of interphase (G1 and G2).

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(8) Assertion: Cell growth is a continuous process in plants

Reason: meristematic tissue is the ever-growing tissue in tips of roots and plants

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(9) Assertion: Mitosis involves replication and equitable distribution of all the chromosomes 

Reason: the cells of a multicellular organism have the same number and type of chromosomes.

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

(10) Assertion: Mitosis and meiosis are two same processes

Reason: Both processes are responsible for somatic cell division

a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.

c.) If assertion is true but the reason is false.

d.) If both assertion and reason are false.

  • Answer in one sentence

Q.1) What is equational division?

Ans. Mitosis is also known as equational division since the number of chromosomes in the parent and progeny cells is the same.

Q.2) State the 4 stages of karyokinesis in mitosis.

Ans. Prophase, Metaphase, Anaphase, and Telophase are the four stages of karyokinesis.

Q.3) How is the syncytium formed?

Ans. In some organisms, karyokinesis is not followed by cytokinesis, resulting in a multinucleate state and the production of syncytium (for example, liquid endosperm in coconut).

Q.4) Why is meiosis important?

Ans. In the life cycle of sexually reproducing organisms, meiosis ensures the generation of the haploid phase, whereas fertilization restores the diploid phase.

Q.5) What is tetrad?

Ans. The complex formed by a pair of synapsed homologous chromosomes is called a bivalent or a tetrad.

Q.6) What is interkinesis?

Ans. Interkinesis is a short-lived stage that occurs between the two meiotic divisions.

During interkinesis, there is no DNA replication.

Q.7) Give the 5 phases of prophase I.

Ans. Based on chromosomal behaviors, prophase I is classified into five phases: Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.

  • Answer in short

Q.1) Describe the events to identify end of prophase?

Ans. The following events can be used to identify the end of prophase:

  1. Mitotic chromosomes are formed when chromosomal material condenses to produce compact mitotic chromosomes. Chromosomes are made up of two chromatids that are connected at the centromere.
  2. The centrosome, which had been duplicated during interphase, begins to move towards the cell’s opposite poles. Asters are microtubules that sprout from each centrosome. Mitotic apparatus is formed of the two asters and spindle fibers.

Q.2) Describe the process of cytokinesis in plant cell.

Ans. 1.) Wall production in plant cells begins in the cell’s center and spreads outward to meet the cell’s existing lateral walls.

2) The creation of the new cell wall starts with the formation of a basic precursor known as the cell-plate, which symbolizes the middle lamella between two adjacent cells’ walls.

Q.3) Give the significance of Meiosis.

Ans. 1.) Meiosis is the technique through which sexually reproducing organisms maintain their specific chromosomal number over generations, despite the fact that the process itself paradoxically results in half in chromosome number.

2.) It also enhances the genetic variety of an organism’s population from generation to generation.

3.) Variations play a crucial role in the evolution process.

  • Answer in brief

Q.1) State the significance of mitosis.

Ans. 1.) Mitosis is almost always limited to diploid cells but haploid cells also divide through mitosis in some lower plants and social insects.

2.) Mitosis normally produces diploid daughter cells with the same genetic complement as the mother cell.

3.) Mitosis is the process by which multicellular organisms grow.

4.) The ratio between the nucleus and the cytoplasm is disrupted as a result of cell expansion. As a result, the cell must divide in order to restore the nucleo-cytoplasmic ratio.

5.) Mitosis makes a substantial contribution to cell repair. The cells of the epidermis’ upper layer, the cells of the stomach lining, and blood cells are all regularly replaced.

6.) Plants grow continuously throughout their lives due to mitotic divisions in the meristematic tissues – the apical and lateral cambium.

Q.2) describe in detail the phases of prophases I.

Ans. 1.) Chromosomes continue to compress throughout leptotene.

2.) Synapsis occurs when chromosomes begin to link together during the zygotene stage.

3.) During pachytene, each bivalent chromosome’s four chromatids become distinct and appear as tetrads. The emergence of recombination nodes, which are locations where non-sister chromatids of homologous chromosomes cross across, characterizes this stage. The disintegration of the synaptonemal complex and the tendency of the bivalents’ recombined homologous chromosomes to segregate from one other, except at crossover locations, signal the start of diplotene. Chiasmata are X-shaped formations in the body.

4.) The terminalization of chiasmata is a sign of diakinesis. The chromosomes are fully condensed during this phase, and the meiotic spindle is put together to prepare the homologous chromosomes for separation. The nucleolus and nuclear envelope both break down at the end of diakinesis. Diakinesis is the shift from prophase to metaphase.

Updated: February 3, 2022 — 10:34 pm

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  1. All question are very amazing

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