Class 11 Biology - Chapter Biological Classification NCERT Solutions | What is the nature of cell-walls in diat
What is the nature of cell-walls in diatoms?
The cell walls construction of diatoms is known as Frustule which consists of two thin overlapping shells fitting into each other just as a soap-box. Their walls are made up of silica. When the diatoms die, the silica in their cell walls gets deposited in the form of diatomaceous earth. This diatomaceous earth is very soft and quite inert. It is used in filtration of oils, sugars, and for other industrial purposes.
More Questions From Class 11 Biology - Chapter Biological Classification
- Q:- Describe briefly the four major groups of Protozoa.
- Q:- State two economically important uses of: (a) Heterotrophic bacteria (b) Archaebacteria
- Q:- Discuss how classification systems have undergone several changes over a period of time?
- Q:- What are the characteristic features of Euglenoids?
- Q:- What do the terms phycobiont and mycobiont signify?
- Q:- Give a brief account of viruses with respect to their structure and nature of genetic material. Also name four common viral diseases.
- Q:- Give a comparative account of the classes of Kingdom Fungi under the following:
(i) Mode of nutrition
(ii) Mode of reproduction - Q:- Plants are autotrophic. Can you think of some plants that are partially heterotrophic?
- Q:-
How are viroids different from viruses?
- Q:- Find out what do the terms algal bloom and red-tides signify.
Popular Questions of Class 11 Biology
- Q:- Why are living organisms classified?
- 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 is the average cell cycle span for a mammalian cell?
- Q:- What are the factors affecting the rate of diffusion?
Recently Viewed Questions of Class 11 Biology
- Q:-
What are the characteristics of prokaryotic cells?
- Q:-
Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions. Comment.
- 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:-
Choose the correct answer among the following:
(a) Gastric juice contains
(i) pepsin, lipase and rennin
(ii) trypsin lipase and rennin
(iii) trypsin, pepsin and lipase
(iv) trypsin, pepsin and renin
(b) Succus entericus is the name given to
(i) a junction between ileum and large intestine
(ii) intestinal juice
(iii) swelling in the gut
(iv) appendix - Q:- What are the conditions necessary for fixation of atmospheric nitrogen by Rhizobium. What is their role in N2 -fixation?
- Q:-
Distinguish between
(a) IRV and ERV
(b) Inspiratory capacity and Expiratory capacity
(c) Vital capacity and Total lung capacity - Q:- When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?
- Q:- Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.
- Q:- What happens to the respiratory process in a man going up a hill?
- Q:- Match the following:
Column I Column II
A T4 i Hypothalamus
B PTH ii Thyroid
C GnRH iii Pituitary
D LH iv Parathyroid
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