Class-9 Biology Important Questions are prepared from the perspective of brushing up the important concepts of Ch-5 “The Fundamental Unit of Life”. Students preparing for various competitive exams will find the questions very helpful .
Q 1 – Lysosome are reservoirs of (1 Marks)
(a) Fat
(b) RNA
(c) Secretory Glycoprotein
(d) Hydrolytic Enzymes
Ans- (d) Hydrolytic Enzymes
Q 2 – Chromatins consist of (1 Marks)
a) DNA
b) RNA
c) RNA and histones
d) DNA and histones
Ans- DNA and histones
Q 3 – Cell organelle that acts as supporting skeletal framework of the cell is – (1 Marks)
a) Golgi apparatus
b) Nucleus
c) Mitochondria
d) ER
Ans – d) ER
Q 4 – Cristae and Oxysomes are associated with- (1 Marks)
a) Mitochondria
b) Plastids
c) Golgi apparatus
d) Plasma membrane
Ans – a) Mitochondria
Q 5 – Cell inclusions are – (1 Marks)
a) Non- living materials present in the cytoplasm
b) Another name of cell organelle
c) Cytoskeletal framework of cell
d) Combined name for cell wall and plasma membrane
Ans- a) Non- living materials present in the cytoplasm
Q 6 – Who proposed the cell theory? (1 Marks)
a) Schleiden and Schwann
b) Watson and Crick
c) Darmin and Wallace
d) Mendel and Morgan
Ans – a) Schleiden and Schwann
Q 7 – Organisms lacking nucleus and membrane bound organelle are – (1 Marks)
a) Diploids
b) Prokaryotes
c) Haploids
d) Eukaryotes
Ans b) Prokaryotes
Q 8 – Animal cell is limited by- (1 Marks)
a) Plasma membrane
b) Shell membrane
c) Cell wall
d) Basement membrane
Ans – a) Plasma membrane
Q 9 – Cell secretion is done by – (1 Marks)
a) Plastids
b) ER
c) Golgi apparatus
d) Nucleolus
Ans- c) Golgi apparatus
Class-9 Biology Important Questions (MCQ) format
Q 10 – Plasmolysis occurs due to – (1 Marks)
a) Absorption
b) Endosmosis
c) Osmosis
d) Exosmosis
Ans – d) Exosmosis
Q 11 – A cell placed in hypertonic solution will – (1 Marks)
a) Shrink
b) Show Plasmolysis
c) Swell up
d) No change in shape or Size
Ans – a) Shrink
Q 12 – The radiant energy of sunlight is converted to chemical energy and is stored as – (1 Marks)
a) AMP
b) ADP
c) ATP
d) APP
Ans – c) ATP (Adenosine Tri Phosphate)
Q 13 – The history of the cell began in 1665 with the publication of Micrographia in London by – (1 Marks)
a) Robert Hooke
b) Robert Brown
c) Strasburger
d) Dujardin
Ans- a) Robert Hooke
Q 14 – Name two cell organelles that have their own genetic material. (1 Marks)
Ans – Mitochondria and Plastids are the two organelles that contain their own genetic material. Both these organelles have their own DNA and Ribosomes.
Q 15 – What are genes? (1 Marks)
Ans- Genes are the segment of DNA which acts as hereditary units which carries information from one generation to other.
Q 16 – What is dictyosome? (1 Marks)
Ans – In plant cells, there are many freely distributed subunits of golgi apparatus known as dictyosomes.
Q 17 – Which type of plastids help in photosynthesis? (1 Marks)
Ans – Chloroplast
Q 18 – Is there any animal cell that lacks lysosomes? (1 Marks)
Ans – Mammalian RBCs (Red Blood Corpuscles) lacks lysosomes.
Q 19 – Name the cell present in the body which is of greatest length. (1 Marks)
Ans – Nerve cell
Q 20 – Name the organelle which is called the kitchen of the cell and powerhouse of the cell (2 Marks)
Ans –
kitchen of the cell – Chloroplast
powerhouse of the cell – Mitochondria
Class-9 Biology Important Questions (Short Answer Types)
Q 21 – Write a short note on cell theory. (3 Marks)
Ans – The postulates of cell theory:
(a) All the organisms are made up of cell or group of cells.
(b) Cell is the structural and functional unit of life.
(c) All the cells arise from the pre-existing cells.
Q 22 – Define endosmosis and exosmosis? (3 Marks)
Ans – Endosmosis – The movement of water into a cell (low concentration) from the hypotonic solution (high concentration) in which the cell is placed through a selectively permeable membrane.
Exosmosis – The movement of water from the cell (high concentration) to the hypertonic solution(low concentration) in which it is placed through a selectively permeable membrane.
Q 23 – What function is provided to the cell by Golgi apparatus? (4 Marks)
Ans –
1) Packages synthesised material in cell and dispatches to the targeted sites.
2) Produces vacuoles, vesicles containing cellular secretions like enzymes, proteins.
3) Involved in the synthesis of cell wall, plasma membrane and lysosomes.
Q 24 – Give a brief account of structure of plasma membrane. (4 Marks)
Ans – Plasma membrane is a living, flexible, selectively permeable membrane. The structure is made up of phospholipids, proteins, cholesterol, and polysaccharides.
Fluid mosaic model for plasma membrane
Model suggested by Singer and Nicolson.
Highlights of model:
(a) Plasma membrane is a bilayer of phospholipids. The phospholipid bilayer is arranged with their hydrophilic heads protruding to the outside and the hydrophobic tails inside.
(b) Two types of proteins are present in the structure:
Intrinsic proteins-these proteins float in the fluid phospholipid forming a channel between inside and outside environment of the cells.
Extrinsic proteins- these proteins float either of the surfaces.