Class 11 Biology - Chapter Cell cycle and Cell Division NCERT Solutions | Can there be DNA replication without cel
Welcome to the NCERT Solutions for Class 11th Biology - Chapter Cell cycle and Cell Division. This page offers a step-by-step solution to the specific question from Excercise ".$ex_no." , Question 15: can there be dna replication without cell division....
Question 15
Can there be DNA replication without cell division?
Answer
There can be DNA replication without cell division. During cell division, the parent cell gets divided into two daughter cells. However, if there is a repeated replication of DNA without any cell division, then this DNA will keep accumulating inside the cell. This would increase the volume of the cell nucleus, thereby causing cell expansion. An example of DNA duplication without cell division is commonly observed in the salivary glands of Drosophila. The chromosome undergoing repeated DNA duplication is known as polytene chromosome.
More Questions From Class 11 Biology - Chapter Cell cycle and Cell Division
- Q:- Describe the following:
(a) synapsis
(b) bivalent
(c) chiasmata
Draw a diagram to illustrate your answer. - Q:- How does cytokinesis in plant cells differ from that in animal cells?
- Q:- Describe the events taking place during interphase.
- Q:- Why is mitosis called equational division?
- Q:- What is G0 (quiescent phase) of cell cycle?
- Q:- Distinguish anaphase of mitosis from anaphase I of meiosis.
- Q:- 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 - Q:- 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 - Q:- Find examples where the four daughter cells from meiosis are equal in size and where they are found unequal in size.
- Q:- Can there be mitosis without DNA replication in S phase?
Popular Questions of Class 11 Biology
- Q:- Why are living organisms classified?
- Q:- Discuss how classification systems have undergone several changes over a period of time?
- Q:- What is the basis of classification of algae?
- Q:- What are the difficulties that you would face in classification of animals, if common fundamental features are not taken into account?
- Q:- What is meant by modification of root? What type of modification of root is found in the (a) Banyan tree (b) Turnip (c) Mangrove trees
- Q:- State the location and function of different types of meristem.
- Q:- Answer in one word or one line. (i) Give the common name of Periplaneta americana. (ii) How many spermathecae are found in earthworm? (iii) What is the position of ovaries in the cockroach? (iv) How many segments are present in the abdomen of cockroach? (v) Where do you find malphigian tubules?
- Q:-
Which of the following is not correct?
(a) Robert Brown discovered the cell.
(b) Schleiden and Schwann formulated the cell theory.
(c) Virchow explained that cells are formed from pre-existing cells.
(d) A unicellular organism carries out its life activities within a single cell. - Q:- What are macromolecules? Give examples.
- Q:- What are the factors affecting the rate of diffusion?
Recently Viewed Questions of Class 11 Biology
- Q:- Why is Abscisic acid also known as stress hormone?
- Q:- Fill in the gaps:
(a) Ascending limb of Henles loop is ____________to water whereas the descending limb is___________to it.
(b) Reabsorption of water from distal parts of the tubules is facilitated by hormone____________.
(c) Dialysis fluid contains all the constituents as in plasma except ________.
(d) A healthy adult human excretes (on an average) _______ gm of urea/day. - Q:- Draw labelled diagrams of the following:
(a) Neuron
(b) Brain
(c) Eye
(d) Ear - Q:- Give a comparative account of the classes of Kingdom Fungi under the following:
(i) Mode of nutrition
(ii) Mode of reproduction - Q:- What are the reasons that you can think of for the arthropods to constitute the largest group of the animal kingdom?
- Q:- Match the following:
(a) Operculum (i) Ctenophora
(b) Parapodia (ii) Mollusca
(c) Scales (iii) Porifera
(d) Comb plates (iv) Reptilia
(e) Radula (v) Annelida
(f) Hairs (vi) Cyclostomata and Chondrichthyes
(g) Choanocytes (vii) Mammalia
(h) Gill slits (viii) Osteichthyes - Q:- Fill in the blank spaces:
(a) All mammals (except a few) have __________ cervical vertebra.
(b) The number of phalanges in each limb of human is __________
(c) Thin filament of myofibril contains 2 F actins and two other proteins namely __________ and __________.
(d) In a muscle fibre Ca++ is stored in __________
(e) __________ and __________ pairs of ribs are called floating ribs.
(f) The human cranium is made of __________ bones. - Q:- Find out how much cellulose is made by all the plants in the biosphere and compare it with how much of paper is manufactured by man and hence what is the consumption of plant material by man annually. What a loss of vegetation!
- Q:- Why are the classification systems changing every now and then?
- Q:- Which hormone deficiency is responsible for the following?
(a) Diabetes mellitus
(b) Goitre
(c) Cretinism
6 Comment(s) on this Question
Saurabh
2019-07-19 18:42:45
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Saurabh
2019-07-19 18:41:28
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Mango
2019-05-31 14:23:17
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2018-11-11 23:16:44
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2018-09-25 16:18:01
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2017-10-28 01:38:38
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