Selina solutions for कन्साइस बायोलॉजी [इंग्रजी] इयत्ता १० आयसीएसई chapter 2 - Structure of chromosome, cell cycle and cell division [Latest edition]

Fill in the blank:
Chromatin fibre is made up of DNA and ______.

The two sister chromatids of a chromosome are attached to each other at ______.

The structure of DNA was first discovered by ______.

The three components of a nucleotide are ______, ______ and ______.

DNA strand wound around a histone octamer forms a complex called a ______.

A specific sequence of nucleotides on a chromosome constitutes a ______.

The Chromatin material is formed forms of ______.

The term “chromosomes” literally means ______.

The number of chromosomes in a certain type of cell division is halved. This kind of cell division occurs in ______.

Synthesis phase in the cell cycle is called so, because of the synthesis of more ______.

In which one of the following options the two stages of mitosis have been given in correct sequence?

The new cells are to be produced for all except:

The chromosomes are duplicated in ______.

Triple hydrogen bonds are present between ______.

In the cells of a human male body, the number of autosomes is ______.

The basis of genetic variation in the living organisms during mitosis occurs due to ______.

After a mitotic cell division, a human female cell will have ______.

The correct sequence of phases in interphase is ______.

The phase of karyokinesis which is almost the reverse of prophase is ______.

The lengthwise arrangement of DNA mainly consists of a phosphate group attached with ______.

The number of histone proteins associated with the DNA in a nucleosome is ______.

The pyrimidine bases of DNA are ______.

The female gamete/egg cell of a human cell will have ______.

The figure given alongside was shown to the students of class 10 in the laboratory under a compound microscope. They were told to observe the slide, identify the stage of mitotic cell division and mention the number of chromosomes which would be found in the daughter cells. Which of the following will be the correct response?

Assertion (A): Both centromere and centrosome are parts of a chromosome.

Reason (R): The centromere is the region where spindle fibres attach, while the centrosome helps in the formation of spindle fibres.

Assertion (A): The basic structural unit of DNA is nucleotide.

Reason (R): DNA is composed of repeating nucleosome which are made up of three components - pentose sugar, phosphate group and nitrogenous bases.

Assertion (A): Centrosome is the point of attachment of two chromatide of a chromosoms.

Reason (R): Centrosome initiates and regulates the process of cell division as it helps in the formation of spindle fibres.

Assertion (A): Meiosis is the kind of cell-division which occurs during gamete formation in the gonads.

Reason (R): During meiosis, chromosome number remains the same in parent cell and daughter cells which is very significant to maintain the identity of the organism.

Name the repeating components of each DNA strand lengthwise.

Name the complex consisting of DNA strand and a core of histones.

Name the type of bond which joins the complementary nitrogenous bases. 

Name the three components of a nucleotide.

Imagine one cell (A) has undergone one mitotic division and another cell (B) has completed its meiotic division. How many cells would the two produce?

Cell A: ______

Cell B: ______

Match the events given in column A with the phase in mitotic cell division in column B. 

DNA replicates in the ______ of the cell cycle.

Mitosis occurs in our ______ cells.

Meiosis occurs only in __________ cells.

Humans have 46 chromosomes. Their sperms and eggs will have ______ chromosomes each.

During the pairing of chromosomes in meiosis, the ________ chromosomes come to lie side by side.

The two non-sister chromatids of a paired chromosome are attached to each other at ______ during the process of crossing over.

Name these:

Two main constituents of Chromatin

Name these:

Two kinds of Nucleic acids

Name the three components of a nucleotide.

Name these:

Four Nitrogenous bases

Name these:

Two kinds of Nitrogenous bases

Name these:

Two components of Nucleosome

Name the following:

The two kinds of cell division found in living organisms.

Name these:

Four main phases of Karyokinesis

Name these:

Two steps of the process Mitosis

Name these:

Two kinds of haploid cells of human body

Correct the following statement if there is any mistake.  

The four nitrogenous bases in the DNA are Guanine, Thiamine, Adrenaline and Cytosine. 

Correct the following statement if there is any mistake:

Genes are specific sequences of bases on a chromosome .

Correct the following statement if there is any mistake: 

A nucleotide is composed of a sulphate, a sugar (pentose) and a nitrogenous base .

Correct the following statement if there is any mistake:

Nucleosomes are groups of cysteine molecules surrounded by DNA strands.

Correct the following statement if there is any mistake: 

If there are 46 chromosomes in a cell, there will be 23 chromatin fibres inside the nucleus during interphase.

Define the following term:

Chromosome

Define the following term:

Gene

Define cell division.

Define the following term:

Chromatid

Define the following term:

Aster

Give a reason for the following:
Gametes must be produced by meiosis for sexual reproduction.

Give reason:

Why is meiosis referred to as 'reductional division'?

Give reason:

The children of the same parents, howsoever similar, are different from each other in certain aspects.

Differentiate between cytokinesis and karyokinesis.

Discuss with your teacher and find out how to distinguish between RNA and DNA.

Distinguish between the following:

Nucleosome and Nucleotide

Differentiate between Centrosome and centromere.

State the difference between:

Haploid and diploid

Write the full form of the following abbreviation:

DNA

Write the full form of the following abbreviation:

RNA

Given below is a set of four term. Choose the odd one and write the category of the remaining term:

Given below is a set of four term. Choose the odd one and write the category of the remaining term:

Given below is a set of four term. Choose the odd one and write the category of the remaining term:

Given below is a set of four term. Choose the odd one and write the category of the remaining term:

Given below is a schematic diagram of a portion of DNA.

1. How many strands are shown in the diagram?
2. How many nucleotides have been shown in each strand?
3. Name the parts numbered 1, 2, 3, 4 and 5 respectively.
4. Name the DNA unit constituted by the parts 1, 2, 3 collectively.

The three sketch (A, B and C) are intended to represent the replication of DNA.

What should be their correct sequence, starting with the first and ending with the last? …… 

The diagram below represents a stage during cell division. Study the same and then answer the questions that follow: 

1. Name the parts labelled 1, 2, and 3.
2. Identify the above stage and give a reason to support your answer.
3. Mention where in the body this type of cell division occurs.
4. Name the stage prior to this stage and draw a diagram to represent the same.

Draw a labelled diagram to show the metaphase stage of mitosis in an animal cell having ‘6’ chromosomes. 

The diagram given below represents a certain phenomenon which occurs during meiosis. Name and explain the phenomenon by using the terms homologous chromosomes, chromatids, crossing over. 

Given below is a diagram representing a stage during mitotic cell division in an animal cell Examine it carefully and answer the questions which follow.

1. Identify the stage. Give one reason in support of your answer.
2. Name the cell organelle that forms the ‘aster’.
3. Name the parts labelled 1, 2 and 3.
4. Name the stage that follows the one shown above; how is that stage identified?
5. Mention two differences between mitosis and meiosis with regards to:
   1. The number of daughter cells produced.
   2. The chromosome number in the daughter cells.

Given below are three diagrammatic sketches (A, B and C) of one and the same particular phase during mitotic type of cell division.

1. Identify the phase.
2. What is the diploid number of chromosomes shown in them?
3. Identify whether these are animal cells or plant cells? Give reasons.
4. Which of these is/are shown in the correct direction?
   1. Only A
   2. Only B
   3. Only A and C
   4. All the three

Shown below are four stages (A, B, C, D) (not in sequence) of a certain kind of cell division.

1. Is it a plant cell or an animal cell? Give two reasons.
2. Is it undergoing mitosis or meiosis?
3. What should be the correct sequence of these four stages among themselves?
4. Name the stage that should precede the earliest of these stages.
5. Draw the stage names above inside the blank space provided.