Revision Notes for ICSE Class 10 Biology Chapter 2 - Free PDF Download
FAQs on ICSE Class 10 Biology Revision Notes Chapter 2 - Cell Cycle, Cell Division, organizations, and Structure Of Chromosomes
1.What is cell division? Why is cell division necessary?
The process by which a parent parent cell divides itself into two or more daughter cells is called cell division. The Cell division is usually a part of a large cell cycle.
The cell division is of two types:
Mitosis:
This is also called somatic division as it occurs during the formation of somatic cells or body cells.
Mitosis is also an equational division in which a parent cell divides itself into two identical daughter cells and each of the daughter cells contains the same number and kind of chromosomes as are present in the parent cell which divides itself.
The development of an individual from the zygote to the adult stage takes place through mitotic cell divisions.
Mitosis occurs in two steps:-
Karyokinesis (nuclear division)
Cytokinesis (a division of the cytoplasm)
Mitosis is further divided into four stages:-
Prophase,
Metaphase,
Anaphase and
Telophase.
While Cytokinesis is of two types:-
Cleavage cytokinesis (that occurs in animals and some lower plants).
Cell plate cytokinesis (occurs in plants)
Meiosis:
In this, the reduction division occurs only in the reproductive cells at the time of gamete formation.
By this process, four daughter cells are formed from a single parent cell and are genetically different from the parent.
The chromosome number in the daughter cell or gametes reduces to half (haploid).
Meiosis consist of two cell division:- Meiosis I and Meiosis II
Meiosis I | Meiosis II |
Prophase I | Prophase II |
Metaphase I | Metaphase II |
Anaphase I | Anaphase II |
Telophase I | Telophase II |
2. Cell division is necessary because of the following reasons:-
A cell is required to divide to maintain continuity from one generation to another generation.
In multicellular organisms, cell division plays an important role in the formation of gametes.
Old and worn-out cells are regularly repaired by the means of cell division.
In unicellular organisms like an amoeba, cell division is the means of reproduction whereas in multicellular organisms; it is the means of tissue growth and maintenance.
Mitosis helps maintain a similar number and type of chromosomes in all cells.
Meiosis helps produce lots of variation due to the independent assortment of chromosomes and crossing over.
2.What role do the chromosomes have in cell division?
The Function of Chromosomes is varied and important. The Chromosomes have a unique structure that keeps the DNA tightly wrapped around the proteins called histones. Chromosomes are the thread-like structure that is found in the nuclei of both animal and plant cells. During the process of cell division, the DNA needs to remain intact and keep its even distribution throughout the cells. So, each chromosome is one long single molecule of DNA. This DNA contains important genetic information in the chromosome.
3.How do I study for ICSE Class 10 biology?
For the students preparing for the ICSE class 10 biology examination, they are advised to read the ICSE Class 10 Biology textbook regularly and also cover as many sample papers as possible, along with giving mock tests, which will introduce them to a variety of questions. The students should also prepare the projects and activities along with the practical work as quickly as possible to concentrate on the theory part and complete the entire syllabus. This will help the candidates to understand their strong and weak areas and work on improving them. Moreover, they will be able to get an idea of the paper pattern and simultaneously revise the concepts.
4.What is the role of revision notes?
The revision notes play an important part in the preparation of the students as it performs the following functions:
Preparing front eh revision notes helps the student to improve their memory.
The Study notes increase the attention of the candidate as they will be able to learn from a single document rather than going through several textbooks.
It helps the students to have an organized study material which helps build focus and reduce the wastage of time for the students.
This builds separate key points from supporting material which is not available everywhere in the textbooks, references, etc.
5.What are the types of cell division?
The process of Cell division takes place when a parent cell divides itself into two or more cells known as daughter cells. The Cell division usually occurs as part of a larger cell cycle during the process.
Types of Cell Division- There are primarily three types of cell division and include the following.
Mitosis: The process with which cells make exact copies of themselves. In almost all the body’s cells, including skin, eyes, muscle and hair cells too Mitosis is observed.
Meiosis: It is a type of cell division in which sperm or egg cells are produced instead of identical daughter cells as in mitosis.
Binary Fission: In this Single-celled organisms like bacteria replicate themselves for reproduction.