Saturday, June 16, 2012


Fundamental Unit Of Life :  Class IX Biology : Fill in the Blanks
1. A -------------is the basic structural and functional unit of all life forms.
Ans: cell
2. Study of structure and composition of cell is called as ------------
Ans: “Cytology”.
3. Cell was first observed by “Robert Hooke” in a dead cork slice in the year 1665. He described about this in his book -----------------
Ans: “Micrographic”.
3. The word cell was derived from a Greek word  ----------  which means small room.
Ans: “Cellulae”
4. First living cell was discovered by -------------
Ans: A.V. Leeuwenhoek
5.  The term protoplasm was coined  ---------- in 1839.
Ans: by purkinje
6.  Protoplasm was discovered by     ------------ and named as sarcode.
Ans: “Felix Dujardin”
7.   --------- is an aggregate of various chemicals such as water, ions, salts and other organic
molecules like proteins, carbohydrates, fats, nucleic acids, vitamins etc.
Ans: Protoplasm
8. Two biologists, “Schleiden and Schwann” gave the “Cell theory” which was later on expanded by -------------
Ans: “Rudolf Virchow ”.
9.  ---------- are the exceptions of cell theory.
Ans: Viruses
10. --------------- cell are primitive and incomplete and have less developed nucleus without nuclear membrane and nucleolus. e.g. Bacteria
Ans. Prokaryotic cells:
2. What is the advantage of multicellularity over unicellularity?
Ans- Division of labor.
3. What are the chromosomes made up of?
Ans- DNA & proteins
4. A cell placed in a solution swells up. What kind of solution is it? Why does it happen?
Ans- It is a hypotonic sol ution & water enters the cell by endosmosis causing the cell to swell up.
5. Why are lysosomes known as “suicidal bags”?
Ans- They secrete powerful digestive enzymes to digest the worn out and damaged cell organelles as well as the cell itself when it loses its functional ability.
6.Why is the nucleus so significant in a cell?
Ans- Nucleus has the following important functions-
(i) It controls all cell activities
(ii) It contains hereditary material that transmits hereditary information from one generation to the next
(iii) It helps in cell division
7. Differentiate between plant and animal cells.
1- Surrounded by two membranes- cell wall & cell membrane.
2- Possess three types of plastids chloroplasts, chromoplasts, leucoplasts.
3- Do not possess lysosomes.
4- Nucleus is towards the periphery.
5- Centrioles are absent
1- Surrounded only by cell / plasma membrane.
2-Do not possess plastids.
3-Possess lysosomes
4 -Nucleus is in the center .. 
5-Centrioles present & help in cell division.
8. Give the major functions of the following cell organelles-
(a) Endoplasmic reticulum RER-- Synthesis of proteins as it has ribosomes attached to it
SER- Synthesis of lipids required for making cell membrane
(b) Golgi apparatus-----------Storage & packaging of various products.
(c) Mitochondria------Production of ATP(Adenosine Triphosphate) which is a source of energy.
(d) Ribosomes ---Protein synthesis
(e) Golgi ApparatusStorage & packaging of various products.
(f) LysosomesDigestion of worn out & damaged organelles

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1 comment:

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CBSE syllabus 

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