Class 9 Science - Chapter The Fundamental Unit of Life NCERT Solutions | Who discovered cells, and how?
Who discovered cells, and how?
Robert Hooke found cells in 1665 while analyzing a flimsy cut of stopper through a self-planned magnifying lens. He saw that the plug looked like the design of a honeycomb consisting of numerous little compartments. These little boxes are called cells.
More Questions From Class 9 Science - Chapter The Fundamental Unit of Life
- Q:-
Carry out the following osmosis experiment:
Take four peeled potato halves and scoos each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D. - Q:-
How does an Amoeba obtain its food?
- Q:-
Why is the cell called the structural and functional unit of life?
- Q:-
Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.
Prokaryotic Cell Eukaryotic Cell 1. Size : generally small (1-10 μm)
1 μm = 10-6 m1. Size generally large (5-100 μm) 2. Nuclear region: ________________
and known as _________________2. Nuclear region: well defined
andsurrounded by a nuclear
membrane3. Chromosome: single
3. More than one chromosome 4. Membrane-bound cell organelles absent 4. _______________________
_______________________ - Q:-
Why are lysosomes known as suicide bags?
- Q:-
Where do the lipids and proteins constituting the cell membrane get synthesised?
- Q:-
How is a prokaryotic cell different from a eukaryotic cell?
- Q:-
How do substances like CO2 and water move in and out of the cell? Discuss.
- Q:-
Make a comparison and write down ways in which plant cells are different from animal cells.
- Q:-
What is osmosis?
Popular Questions of Class 9 Science
- Q:-
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
- Q:-
State the universal law of gravitation.
- Q:-
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
- Q:-
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
- Q:-
What is meant by a pure substance?
- Q:-
How does the sound produced by a vibrating object in a medium reach your ear?
- Q:-
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
- Q:-
What are canal rays?
- Q:-
State any two conditions essential for good health.
- Q:-
How is our atmosphere different from the atmospheres on Venus and Mars?
Recently Viewed Questions of Class 9 Science
- Q:-
On what bases are plants and animals put into different categories?
- Q:-
Give the names of the elements present in the following compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate. - Q:-
How do gymnosperms and Angiosperms differ from each other?
- Q:-
Why does an object float or sink when placed on the surface of water?
- Q:-
What are the methods of preventing or reducing soil erosion?
- Q:-
Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of a candle. - Q:-
A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 m/s2, find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?
- Q:-
How are the wavelength and frequency of a sound wave related to its speed?
- Q:-
What type of mixtures are separated by the technique of crystallisation?
- Q:-
Which tissue makes up the husk of coconut?
- All Chapters Of Class 9 Science
- All Subjects Of Class 9