Class 10 Biology Chapter 1
Structure of Chromosome, Cell Cycle and Cell division Important Questions

Here, you'll find important questions related to Chapter 1: Structure of Chromosome, Cell Cycle, and Cell Division for ICSE Class 10 Biology. These questions have been crafted to assist students in their preparation for the ICSE Class 10 Biology Examination in 2023–24. By practising various question types, students can clarify their doubts, enhance their exam readiness, boost their confidence, and refine their problem-solving skills.

Introduction

In the first chapter,Structure of Chromosome, Cell Cycle and Cell division of ICSE Class 10 Biology, you will explore fundamental aspects such as the underlying structure of chromosomes, key terminology associated with chromosomes, and the concepts of the cell cycle and cell division. Understanding these topics is essential, as they form the building blocks of biology. In this introductory chapter, we will delve into the intricate world of chromosomes, where we will uncover the mysteries of their structure, unravel the complexities of the cell cycle, and explore the intricate processes of cell division. As you progress through this chapter, you'll encounter a variety of biology questions for Class 10 ICSE, providing you with the opportunity to deepen your understanding of these crucial biological concepts. We will also touch upon some ICSE Class 10 biology questions and answers to help you prepare effectively for your examinations. So, let's embark on this journey to unravel the secrets of life at the cellular level.

What are the Structure of Chromosomes, Cell Cycle, and Cell Division ?

The structure of chromosomes, the cell cycle, and cell division are fundamental concepts in biology, particularly for Class 10 ICSE students studying for their exams. Let's break down each of these concepts:

• Structure of Chromosomes: Chromosomes are thread-like structures found in the nucleus of eukaryotic cells. They consist of DNA and associated proteins, and their primary function is to carry and transmit genetic information. Chromosomes have a distinctive X-shape when a cell is about to divide, consisting of two sister chromatids joined by a centromere. Understanding the structure of chromosomes is crucial for comprehending how genetic information is organised and passed on during cell division.
• Cell Cycle: The cell cycle is a series of stages that a cell goes through as it grows and divides. It consists of three main phases: interphase, mitosis (or meiosis in specialised cases), and cytokinesis. Interphase is the phase when the cell prepares for division, while mitosis is the actual process of cell division, leading to the formation of two identical daughter cells. Cytokinesis is the final step, where the cell's cytoplasm divides, completing the cell division process.
• Cell Division: Cell division is the process by which a single cell divides into two or more daughter cells. There are two primary types of cell division: mitosis and meiosis. Mitosis is responsible for the growth, repair, and maintenance of multicellular organisms, as it produces genetically identical daughter cells. In contrast, meiosis is a specialised form of cell division that occurs in the reproductive organs, resulting in the formation of gametes (sperm and egg cells) with half the number of chromosomes. This process ensures genetic diversity in offspring.

These concepts are crucial for students preparing for ICSE Class 10 biology exams, as they form the basis of genetics and cell biology. Practising ICSE Class 10 biology questions and answers related to these topics is essential for a comprehensive understanding and successful examination preparation. Explore further with Oswal.io for ICSE Class 10 biology important questions to strengthen your knowledge in these fundamental areas of biology.

Class 10 Biology Structure of Chromosome, Cell Cycle and Cell division Important Questions and Answers

Q1. The term Meiosis was coined by :

Options

(a) Farmer and Moore
(b) Winiwarter
(c) Flemming
(d) Strasburger

Ans. (a) Farmer and Moore

Explanation:
The term meiosis was coined by J. B. Farmer and J. E. Moore in 1905. It is derived from the Greek word meaning 'reduction'.

Q2. Meiosis __________ the parental chromosome number.

Options

(a) Doubles
(b) Reduces
(c) Maintains
(d) Stabilises

Ans. (b) Reduces
Explanation:
Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells.

Q3. Differentiate between Mitosis and Meiosis.

Explanation:‍

Q4. Write the name of various steps of the cell cycle.

Explanation:‍

Q5. Give a labelled diagram to illustrate amitosis.

Explanation:‍

ICSE Class 10 Biology Chapter wise Important Questions

Conclusion

The concepts of the structure of chromosomes, the cell cycle, and cell division are pivotal in the field of biology, particularly for ICSE Class 10 students. Understanding the intricacies of chromosome organisation, the phases of the cell cycle, and the mechanisms behind cell division is essential for grasping the fundamentals of genetics and cellular biology. To excel in these topics and prepare effectively for examinations, students are encouraged to delve deeper into their studies by exploring ICSE Class 10 biology questions and answers. Additionally, for those seeking extra practice and a more comprehensive learning experience, oswal.io offers a rich collection of questions and resources that can further enhance your grasp of this chapter's content.

Frequently Asked Questions

Q1 : What are the rungs of the “DNA ladder” made of?

Ans: The rungs of the DNA ladder are made of four types of nitrogenous bases. These are Adenine (A), Guanine (G), Cytosine (C) and Thymine (T).

Q2 : “First meiotic division is the reduction division”. What does the word ‘reduction’ refer to in this statement?

Ans:  In the above statement, reduction means that the number of chromosomes in the sex cells is halved. For example, out of the 23 pairs of chromosomes in humans, only single chromosomes i.e. one number of each pair are passed on to the sex cells.

Q3 : “Gametes must be produced by meiosis for sexual reproduction”. Why is it so?

Ans: Gametes must be produced by meiosis for sexual reproduction because, when the male and female gametes fuse during fertilisation, the normal double number of chromosomes is reacquired.

Q4 : What are chromosomes?

Ans:  When a normal unstained living cell is observed under a light microscope, its nucleus may not appear to contain any particular thing inside. But when the same cell is stained with suitable dyes, several structures become noticeable in the nucleus.The nucleus contains most of the cell’s DNA which is organised into discrete units called chromosomes. Each chromosome contains one long DNA molecule associated with many proteins. This complex of DNA and Proteins is called the chromatin. When a cell is not dividing, the chromatin under an electron microscope appears to be in the form of very long and extremely thin darkly stained fibre.

Q5 : What are genes?

Ans: Genes are specific sequences of nucleotides on a chromosome that encode particular proteins which express in the form of some particular feature of the body. They are the units of heredity which are transferred from parents to offspring and are responsible for some specific characteristics of the offspring.Lots of regions in between genes are just nonfunctional. Such areas (about 99 per cent of the total DNA) show tremendous variations from person to person and help in identification of the individual by what is popularly known as DNA fingerprinting.