Chapter 10 : Cell Cycle and Cell Division

Write briefly the significance of mitosis and meiosis in multicellular
organism.

Write brief note on the following
a. Synaptonemal complex
b. Metaphase plate

Differentiate between the events of mitosis and meiosis

What are the various stages of meiotic prophase-I? Enumerate the
chromosomal events during each stage?

Comment on the statement – Telophase is reverse of prophase.

How does cytokinesis in plant cells differ from that in animal cells?

Name a cell that is found arrested in diplotene stage for months and
years. Comment in 2-3 lines how it completes cell cycle?

Comment on the statement – Meiosis enables the conservation of specific
chromosome number of each species even though the process per se,
results in reduction of chromosome number.

Two key events take place, during S phase in animal cells, DNA replication
and duplication of centriole. In which parts of the cell do events occur?

Name the pathological condition when uncontrolled cell division occurs.

Both unicellular and multicellular organisms undergo mitosis. What
are the differences, if any, observed in the process between the two?

What would be the consequence if each of the following irregularities
occur during mitosis?
a. Nuclear membrane fails to disintegrate
b. Duplication of DNA does not occur
c. Centromeres do not divide
d. Cytokinesis does not occur.

The following events occur during the various phases of the cell cycle,
Name the phase against each of the events.
a. Disintegration of nuclear membrane _________________________
b. Appearance of nucleolus _________________________
c. Division of centromere _________________________
d. Replication of DNA _________________________

While examining the mitotic stage in a tissue, one finds some cells with
16 chromosomes and some with 32 chromosomes. What possible reasons
could you assign to this difference in chromosome number. Do you think
cells with 16 chromosomes could have arisen from cells with 32
chromosomes or vice versa?

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?

Mitochondria and plastids have their own DNA (genetic material). What
is known about their fate during nuclear division like mitosis?

State the role of centrioles other than spindle formation.

In which phase of meiosis are the following formed? Choose the answers
from hint points given below.
a. Synaptonemal complex ____________________________
b. Recombination nodules ____________________________
c. Appearance/activation of ____________________________
enzyme recombinase
d. Termination of chiasmata ____________________________
e. Interkinesis ____________________________
f. Formation of dyad of cells ____________________________

It is observed that heart cells do not exhibit cell division. Such cells do
not divide further and exit ___________ phase to enter an inactive stage
called ___________ of cell cycle. Fill in the blanks.

It is said that the one cycle of cell division in human cells (eukaryotic
cells) takes 24 hours. Which phase of the cycle, do you think occupies
the maximum part of cell cycle?

At what stage of cell cycle does DNA synthesis take place?

An anther has 1200 pollen grains. How many pollen mother cells must
have been there to produce them?

If a tissue has at a given time 1024 cells, how many
cycles of mitosis had the original parental single cell undergone?

What attributes does a chromatid require to be classified as a
chromosome?

Which part of the human body should one use to demonstrate stages in
mitosis?

Given that the average duplication time of E.coli is 20 minutes, how
much time will two E.coli cells take to become 32 cells?

Which tissue of animals and plants exhibits meiosis?

Name a stain commonly used to colour chromosomes.

Which of the phases of cell cycle is of longest duration?

Between a prokaryote and a eukaryote, which cell has a shorter cell
division time?

What is mitosis? Give a brief account of mitosis in animal cell?

What are homologous chromosomes? What happens to homologous
chromosomes during meiosis ?

Write six differences between mitosis & meiosis?

Enumerate the significance of mitosis?

Write three processes which take place in interphase?

Why is meiosis called reductional division & mitosis called equational
division?

Name the cell division concerned with cancer?

What is G_o phase?

At which stage of meiosis crossing over of genetic material takes place?

Explain the various phases of meiosis II division?

Differentiate between animal cell mitosis & plant cell mitosis?

What is the significance of meiosis?

How does duration affect the cell cycle in organism?

Distinguish between metaphase of mitosis & metaphase I of meiosis?

What is the importance of chromosomes replication during interphase?

Name the cells in which meiosis occurs?

Which structure of animal cell forms the asters of spindle?

Name the stage of cell division in which paired homologous chromosomes
get shortened & thickened?

Analyse the events during every stage of cell cycle and notice how the following two parameters change (i) number of chromosomes (N) per cell (ii) amount of DNA content (C) per cell

Can there be DNA replication without cell division?

Can there be mitosis without DNA replication in ‘S’ phase?

. Discuss with your teacher about (i) haploid insects and lower plants where cell-division occurs, and (ii) some haploid cells in higher plants where cell-division does not occur.

What is the significance of meiosis?

List the main differences between mitosis and meiosis.

Distinguish anaphase of mitosis from anaphase I of meiosis.

Find examples where the four daughter cells from meiosis are equal in size and where they are found unequal in size.

How does cytokinesis in plant cells differ from that in animal cells?

Describe the following: (a) synapsis (b) bivalent (c) chiasmata Draw a diagram to illustrate your answer

Name the stage of cell cycle at which one of the following events occur: (i) Chromosomes are moved to spindle equator. (ii) Centromere splits and chromatids separate. (iii) Pairing between homologous chromosomes takes place. (iv) Crossing over between homologous chromosomes takes place.

Why is mitosis called equational division?

What is Go (quiescent phase) of cell cycle?

Distinguish cytokinesis from karyokinesis

What is the average cell cycle span for a mammalian cell?