Metaphase

Q. In which of the following stages of cell cycle does both centromere splitting and separation of sister chromatids occur?

1. First Gap phase
2. Anaphase
3. Second Gap phase
4. Telophase

Q.

What is constitutive heterochromatin and facultative heterochromatin?

Q.

State whether the following statement is true or false

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

1. True
2. False

Q. Four different steps that occur during meiosis are given in the following list :
(i) Complete separation of chromatids
(ii) Pairing of homologous chromosome
(iii) Linning up of paired chromosome on the equatorial plane
(iv) Crossing over between chromatids

1. (i), (ii), (iii), (iv)
2. (iii), (ii), (iv), (i)
3. (iii), (ii), (i), (iv)
4. (ii), (iv), (iii), (i)

Q.

What is the difference between astral rays and spindle fibres?

Q.

The thread-like structures present in the nucleus are

1. nucleolus

2. chromosomes

3. genes

4. ribosomes

Q. The morphology of chromosomes is best understood during _______ stage of mitosis.

1. interphase
2. telophase
3. metaphase
4. prophase

Q.

How are chromatin, chromatid, and chromosomes related to each other?

Q. Meaning of Dyad of cells and chiasmata in meiosis

Q.

What forms the mitotic apparatus towards the completion of prophase?

Q.

Question 28

A cell has 32 chromosomes. It undergoes mitotic division. What will be the chromosome number (n) during metaphase? What would be the DNA content (C) during anaphase?

Q.

Sieve tube cell is:

1. Uninucleate

2. Multinucleate

3. Enucleate

4. Dead

Q. Select the correct option with respect to mitosis:

1. Chromatids start moving towards opposite poles in telophase
2. Chromosomes move to the spindle equator and get aligned along equatorial plate in metaphase
3. Chromatids separate but remain in the centre of the cell in anaphase
4. Golgi complex and endoplasmic reticulum are still visible at the end of prophase

Q.

Give any one key anaphase event that characterizes it.

Q.

Do polar bodies have chromosomes?

Q. Choose the incorrect statement with respect to chromosomal abnormality.

1. Aneuploidy refers to loss or gain of chromosome(s)
2. Triploidy is characterised by the presence of three sets of chromosomes
3. Polyploidy refers to having multiple sets of chromosomes in a cell
4. Triploidy is the presence of three copies of one particular chromosome in all the cells

Q.

Arrange the set of terms in the logical sequence.

Interphase, anaphase, prophase, telophase, metaphase.

Q.

Where is the centromere found in the acrocentric chromosome?

Q. The "cri-du-chat" syndrome in caused by change in chromosome structure involving:

1. Deletion
2. Duplication
3. Inversion
4. Translocation

Q.

Why is the size of chromosomes measured at mitotic metaphase?

Q. Balbiani rings are found in

1. polytene chromosomes
2. diplotene chromosomes
3. Z-DNA
4. Lampbrush chromosome

Q. At meristematic phase, the cells:
(a) Contain large nucleus
(b) Have dense cytoplasm
(c) Lack plasmodesmata
(d) Have high respiration rate
The correct ones are:

1. All a, b, c and d
2. a and b only
3. a, b and d only
4. b, c and d only

Q. Sister chromatids are

1. created when DNA is replicated
2. separated during mitosis
3. attached at the centromere prior to division
4. all of these

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

Column 'A'	Column 'B'
(a) Chromosomes get arranged in a horizontal plane at the equator.	1.Anaphase
(b) Daughter chromosomes move to the opposite poles of a spindle.	2. Prophase
(c) Chromosomes become visible as fine long threads.	3. Telophase
(d) Chromosomes lose their distinctiveness and gradually become transformed into a chromatin network	4. Metaphase

Q. i) Draw a well-labelled diagram to show the metaphase stage of mitosis in an animal cell having four chromosomes.
ii) Mention any two reasons for the population explosion in India.
iii) Give biological reasons for the following.
1) The pituitary gland is also known as the master gland.
2) Gametes have a haploid number of chromosomes.

Q.

Choose the incorrect statement(s) regarding Metaphase of Mitosis.

I. Each chromosome splits up to form 2 chromatids.

II. The newly formed chromatids remain united at centromere on two different

kinetochores.

III. Has only one of unit of DNA from each parent.

IV. Spindle fibres attach to centromere to pull the chromatids toward the poles.

1. I $\&$ II
2. II $\&$ III
3. III $\&$ I
4. IV only.

Q. Middle lamellae of the cell wall mainly contains

1. Ca
2. K
3. Na
4. Mg

Q. If cells in process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested?

1. Anaphase
2. Telophase
3. Metaphase
4. Prophase

Q. Number of chromatids at metaphase is?

1. One in mitosis and two in meiosis
2. Two in mitosis and one in meiosis
3. Two in mitosis and four in meiosis
4. Two each in mitosis and meiosis

Q. The diagram given represents a stage during cell division. Study the same and answer the question that follows.